MadModder

The Shop => Wood & Stuff => Topic started by: S. Heslop on March 21, 2015, 08:42:27 PM

Title: Banjo Build
Post by: S. Heslop on March 21, 2015, 08:42:27 PM
So a while back I had the silly idea of trying to build banjos to sell. And for a good while I was building stupid tools to do jobs the hard way.

Before I built that drum sander I decided to just start actually building a banjo to see how it goes. Then I got distracted again by a friend asking me for help in building skateboards and built that drum sander. I finished the sander but the skateboard thing fell through so I'm getting back to continuing that banjo.

That's my life story out the way. So I started by making some wooden hexagons. The main wood i'm using is meranti, a sort of cheap knock-off mahogany.

(http://iforce.co.nz/i/0gip3wti.krq.jpg)
Despite being careful, I didn't get the angles right. I really have no idea how people manage to do those fancy segmented turnings. I guess they must cut the last segment to fit.

They were glued in two halves and then the joining faces were sanded flat.

(http://iforce.co.nz/i/2bksuqhm.iw3.jpg)
Anyways after being left in the house for two months the meranti hexagons held up fine, but the top one made from goncalo alves shrunk enough to make a huge gap, the individual segments also twisted a huge amount. It's not a very stable wood, evidently.

The idea is that fancy banjos use a metal tone ring that sits between the skin head and the pot, and that gives it a brighter tone. So instead of that I'm going to use a hard wood as the top layer in the pot. That said, i'm not a big believer in tone. I guess there are differences, but which one is better is highly subjective. But it's still something I wanted to try.

(http://iforce.co.nz/i/axvwlgcr.svl.jpg)
The meranti hexagons didn't warp at all, but weren't perfectly flat to begin with. So I sanded them true on the drum sander.

(http://iforce.co.nz/i/gixtn4lt.aw4.jpg)
These were then glued into a stack, on a board of plywood. It was awkward with the thing sliding about on the glue. If or when I do this next, i'll probably drive some pins into the wood to prevent that. A layer of paper should hopefully make it possible to separate the pot from the plywood once it's round.

(http://iforce.co.nz/i/o4mwdxhj.fmc.jpg)
There was still that top layer to sort though. The goncalo alves was too warped to try forcing flat, so I went through my basket of hardwood to try find something else. I first tried using a piece of chechen, and after cutting it up I realised I didn't have enough wood. I'd checked to see how stable chechen was online before cutting it up, and it seemed to rate fairly well. But I was fed up at this point and decided to just cut some apple wood and see how that goes.

(http://iforce.co.nz/i/uhi0z1x2.jeu.jpg)
That was then glued up.


Tomorrow I'm planning to build a rubbish wood lathe to turn the inside of the banjo. The outside will probably be sanded on the spindle sander. I'd actually built that sander with the intention of using it to sand banjo pots round internally, but i've since deiced that it wasn't the best of ideas. I guess i've warmed up to the idea of awkward dangerous looking wood lathes after building the drum sander.

(http://iforce.co.nz/i/p0cb2eg3.jye.jpg)

I measured up some various scraps in the garage and here's what i'm going with so far. I'll probably add a bit more bracing to the headstock side of things, but there's no point in drawing that up I suppose.
Title: Re: Banjo Build
Post by: vtsteam on March 21, 2015, 09:42:34 PM
Simon, have you considered splining those end grain joints? Make a jig for your tablesaw and run the pieces through, then rip up some spline stock and glue it in. You can do that to individual pieces before assembling, or do it at the joints to the ring you.ve already made. It will be easier and much better than doweling for this kind of joint -- gluing surface area where it should be, and grain running across the joint. And you don't need to buy (or make) dowels. If you really want to lock it, spline, and then dowel from the face through the spline, ie wooden fasteners.
Title: Re: Banjo Build
Post by: S. Heslop on March 21, 2015, 10:14:59 PM
Simon, have you considered splining those end grain joints? Make a jig for your tablesaw and run the pieces through, then rip up some spline stock and glue it in. You can do that to individual pieces before assembling, or do it at the joints to the ring you.ve already made. It will be easier and much better than doweling for this kind of joint -- gluing surface area where it should be, and grain running across the joint. And you don't need to buy (or make) dowels. If you really want to lock it, spline, and then dowel from the face through the spline, ie wooden fasteners.

Oh by pin I meant like veneer pins, tiny nails. Just tapping them in a bit and cutting most of the rest off, so that it doesn't want to slide as much when clamping up each layer. I'm a little worried that I might not have gotten each layer lined up properly and won't be able to turn it 11 inches. But if that happens I guess i'll just turn one of the layers a bit narrower than the top, and try pretend it's something decorative.

I'm not expecting the end grain joints to hold that strongly, most of the strength will come from the edge grain joints with each layer.
Title: Re: Banjo Build
Post by: vtsteam on March 21, 2015, 10:37:13 PM
I see. I thought it was just a single thickness, and you were making several at a time.

Woud it be possible to do a single thickness with a splined joint (or a couple splines per joint)?

Apple is a beautiful wood.
Title: Re: Banjo Build
Post by: Lew_Merrick_PE on March 22, 2015, 02:11:46 PM
Simon,

I have been making 5-string banjos for 51 years now.  One of the things that makes the job a lot easier is to cut your "shell wood" into thin (call it 2-2.5 mm thick) strips and laminate them inside of a (hollow) circular jig.  Here in the U.S. nearly all banjo heads are 11 inches in diameter -- making 10.950/10.900 inches the correct OD for the shell.  The circular clamping jig I use has the OD set to 15 inches -- which means that I can use it in my table saw to "trim off" the (inevitable) "mismatch" at the top and bottom edges.  I "wax" the ID of the jig to keep glue from sticking to it.

My "ID Clamp" is an inner tube from a hand truck (5 inch hub, as I recall) that fits on an inner (about 7.5 inches OD) piece with an extension that allows me to inflate it to clamp each "layer" as I laminate the shell.  I find that (about) 30 psi works really well.

I normally make my shells 3.5 inches tall, so I start off with a piece of wood that is 3.75 inches wide and 34.75 inches long.  I "dress" the face of the stock on my joiner and slice off a piece on my bandsaw, take it back to the joiner, and repeat until I have all my strips.  I then use my thickness sander to finish each "layer" to thickness (.090 inches for my approach).  I cut them to length, steam them, and insert them into my jig and force them to round using the "ID Clamp."  The "outer joint" of the shell gets located under the heel of the neck, so the slight "mismatch" is (virtually) never seen.

I make my frailing banjos with a (roughly) 10 mm thick shell.  Bluegrass banjos get a (roughly) 20 mm thick shell.  After the slightly over-tall shell is complete, I return it to the "circular jig" and use that to trim it to length.  I then glue "strips" to the bottom of the shell and trim them flush using a trim-router.  I can then, if so desired, route a "perfling rabit" for final clean-up trim.
Title: Re: Banjo Build
Post by: S. Heslop on March 22, 2015, 04:01:33 PM
Simon,

I have been making 5-string banjos for 51 years now.  One of the things that makes the job a lot easier is to cut your "shell wood" into thin (call it 2-2.5 mm thick) strips and laminate them inside of a (hollow) circular jig.  Here in the U.S. nearly all banjo heads are 11 inches in diameter -- making 10.950/10.900 inches the correct OD for the shell.  The circular clamping jig I use has the OD set to 15 inches -- which means that I can use it in my table saw to "trim off" the (inevitable) "mismatch" at the top and bottom edges.  I "wax" the ID of the jig to keep glue from sticking to it.

My "ID Clamp" is an inner tube from a hand truck (5 inch hub, as I recall) that fits on an inner (about 7.5 inches OD) piece with an extension that allows me to inflate it to clamp each "layer" as I laminate the shell.  I find that (about) 30 psi works really well.

I normally make my shells 3.5 inches tall, so I start off with a piece of wood that is 3.75 inches wide and 34.75 inches long.  I "dress" the face of the stock on my joiner and slice off a piece on my bandsaw, take it back to the joiner, and repeat until I have all my strips.  I then use my thickness sander to finish each "layer" to thickness (.090 inches for my approach).  I cut them to length, steam them, and insert them into my jig and force them to round using the "ID Clamp."  The "outer joint" of the shell gets located under the heel of the neck, so the slight "mismatch" is (virtually) never seen.

I make my frailing banjos with a (roughly) 10 mm thick shell.  Bluegrass banjos get a (roughly) 20 mm thick shell.  After the slightly over-tall shell is complete, I return it to the "circular jig" and use that to trim it to length.  I then glue "strips" to the bottom of the shell and trim them flush using a trim-router.  I can then, if so desired, route a "perfling rabit" for final clean-up trim.

That's some good information. Thanks!

The reason i'm going with the segmented construction is because I was hoping to be able to make some fancy segmented bowl style patterns from the wood. Although i'm just trying to get anything working right now.

My current banjo is cobbled together from a banjo neck, some hardware, and a wooden box that had paints. Kinda like a cigar box banjo but not at all solidly constructed. The whole thing can flex too easily and it goes in and out of tune. I'm long overdue a replacement.


I've all but finished that rubbish lathe. Apologies for the busy photos, it's hard to see whats what.

(http://iforce.co.nz/i/vv4an4cl.ck2.jpg)
(http://iforce.co.nz/i/s5bnsexi.oyk.jpg)

Turned the faceplate round without any issues so i'm fairly convinced it should work.

Also I'm pretty pleased with that router base. It's just screwed into the side of the headstock to hold the drill in place. It's a pretty cheap and flimsy thing, but i've been finding all kinds of uses for it since it grips regular drills. The router/ laminate trimmer itself also works as (and is pretty much built exactly the same as) a die grinder. I found it in a second hand shop.
Title: Re: Banjo Build
Post by: S. Heslop on March 24, 2015, 01:02:14 PM
Didn't get anything done yesterday since I needed some 9mm plywood. I usually buy it from a builders merchants in full sized boards, quartered so I can get them home, but without a car it's a weekend thing. Had a while to wait for the bus up in Consett today so I decided to head to the hardware store and see if maybe they sold some. And sure enough, they did. For a fair price too. 6 for a quarter board.

The hardware store is called Gralands and it's well worth checking out if you're in the area. It's amazing what they fit into a small place. I keep thinking I might take some photos of the place but it's a bit of a dorky thing to do, but afaik hardware stores like that (the sort that sell screws by weight) are a rare thing.

Anyways it's now pissing it down with rain so I've got everything up on the benches in case the garage floods, so there's not alot to do till it stops.
Title: Re: Banjo Build
Post by: S. Heslop on March 24, 2015, 04:41:36 PM
(http://iforce.co.nz/i/gwnvwyfx.cwi.jpg)

Here's what happens when I try be clever. Instead of just clamping a bit of plywood to the table I thought i'd put some threaded inserts into the table to bolt a fancy thing to. I put the first threaded inserts in the wrong place, down at the bottom of those slots, and then realised that the banjo pot would cover them so I couldn't use that to screw it down, so I put a couple further up. Which I put too high so I had to sand the middle part longer.

I also made a mess of trying to make the thing. You can see all the lines where I kept bungling it up, and the slots are terribly long (and cut roughly with a jigsaw) since I kept putting them in the wrong place too.

I also bungled up transferring the banjo pot from the 18mm ply to the 9mm ply, by forgetting to first draw a circle on it so I could find the center again. So I'm probably going to print out a circle and try find a place to fit it, then use that to find the center. At least the paper thing worked and it was possible to remove it from the plywood, although now i'm worried it wont be able to survive the force of being turned on that lathe.
Title: Re: Banjo Build
Post by: vtsteam on March 25, 2015, 09:38:23 AM
Trial and error has a great friend in me, Simon. Keep up the exploration of your ideas! :thumbup: :clap:
Title: Re: Banjo Build
Post by: S. Heslop on March 26, 2015, 11:15:58 PM
Spent the last couple days doing other things for the most part. I'm having trouble again with the sanding sleeves on the spindle sander. I'm mostly going through each half-assed idea I can think of to avoid doing the best solution and copying commercial sanders (that use a rubber block that gets compressed down with a nut, to expand out and grip the sleeve).

Another vaguely interesting thing i've been doing is editing a clip show for some sort of conference (I don't know what to expect but I was asked to do it). Condensing 4 projects into a 5 minute video turned out to be a difficult task. I really expected it to be a quick job but since I can't use the rendered files (they've got baked-in commentary) i've had to sort through all the source clips. So it was almost equivalent to editing 4 videos back to back. I didn't have to record commentary at least.
Title: Re: Banjo Build
Post by: S. Heslop on March 27, 2015, 01:17:35 PM
More fussing with the spindle sander with no luck. I think what I might try doing is cross drilling the spindle and putting a pin in, then making a plywood sleeve of sorts that I'll just glue the sandpaper to directly with a slot to index with the pin. Might make a few sleeves while i'm at it.

I've also got a slight alignment issue that I noticed pretty much after I built the thing, but I didn't give it a whole lot of thought till now. The motor isn't mounted parallel to the rails that it slides on, and fixing that will probably require an almost full disassembly. It causes the spindle to move forwards a bit as it raises up. While I can get around it affecting the work by just switching off the oscillating for a final pass, I doubt it's doing the sandpaper any favours to be heavily pushed into the work each time the spindle moves upwards.

I should've fixed this a long time ago but I tend to leave stuff like this until it's absolutely necessary.
Title: Re: Banjo Build
Post by: S. Heslop on March 29, 2015, 02:31:39 PM
Yet more fussing. Alot of time is spent waiting for glue to dry. I've been trying to bore a 20mm hole into the plywood spindle with no luck. Trying to make crappy reamers out of bits of barstock. That works for shallow holes but it's killing the drill and just causing alot of friction trying to do it with something so deep.

I did think for a bit about making some sort of boring tool using a bit of square high speed steel but at this point I should really just go out and buy a damn 20mm drill. So i'm going to do that tomorrow.

It's always these little jobs that seem to take the longest.

(and in all honesty, I could probably just turn the outside of the thing on the rubbish lathe i'd made too, but i'm dead set on doing it this way. Maybe just to prove the sander wasn't a waste of time).
Title: Re: Banjo Build
Post by: S. Heslop on March 31, 2015, 03:02:24 PM
Got a drill bit. An auger, actually. I'm still not sure what advantages augers have over anything else (maybe if you insist on using an old bit and brace), but they were alot cheaper and longer than the blacksmith drills. I'll probably regret being so tight when I need a 20mm hole in metal.

But anyways, it made a nice hole just the right size. But now i've got yet another problem with the spindle no longer being in axis with the motor's spindle. My best guess is that a bit of sawdust is trapped somewhere in between but it's a bit awkward to get at to see clearly or clean it. So I've got no choice but to disassemble it. Could also just be a problem with the spindle not being balanced, and if that's the case then there's probably no hope of fixing the problem. Garage is a total mess though and needs a good tidying up so I have my workbenches back. Had another thunder storm so I piled everything off the floor that I didn't want to get potentially wet on the benchtops.

This project is going at a glacial pace. Hopefully I've got everything i'll need for now though and can get back to it. But spending the weekend fussing with the sander has killed alot of my enthusiasm.
Title: Re: Banjo Build
Post by: S. Heslop on April 01, 2015, 04:27:07 PM
(http://iforce.co.nz/i/2zv3ltmg.wfa.jpg)

I've been holding off posting pictures since I thought this whole spindle sander tune-up would be a quick and boring job.

Got the spindle trued up. Not sure how it ended up shifting out of alignment. Maybe the metal settled or something when I drilled that hole through the middle. It was trued up the same way as when I built it, with scraping the mating face. Ended up reducing the runout to damn near zero.

(http://iforce.co.nz/i/fghr33lf.ij1.jpg)

Hot off of that I thought i'd tackle the spindle not being parallel to the rails and... well I've got no easy way to adjust it, so after alot of thinking about which way things needed to move I shaved a bit of wood off the inside of the lower motor mounts (the ones held on by a jubilee clip) and tried shimming them. Didn't expect to get this perfect but I figured I could improve the situation a bit.

(http://iforce.co.nz/i/mmhjtqm3.tl5.jpg)

And I think when I put the holes in to begin with I must've just gotten lucky with the placement because I could not get the thing back together at all without it jamming up once the jubilee clip was tightened. Spent more than an hour trying to brute force it with various paper shims. Another interesting thing was inspecting the wear inside the thing. The pin that the crank arm connects to to lift the motor up and down has become fairly loose and it'll probably eventually split the plywood. A few posts ago I was patting myself on the back for a good design but I think this is a weak part and could probably do with some fixing up too. A couple of screws might just do the job in holding the plywood together against splitting.

Anyways I'm probably going to have to think up a solution for the lower mounts that makes them more easily adjustable. The alternative could be to make the parts again, and use the spiked ends of the bars once more to locate the hole centers. Perhaps that way is more accurate than I give it credit for.

No such thing as a quick job I guess.
Title: Re: Banjo Build
Post by: S. Heslop on April 01, 2015, 06:56:27 PM
(http://iforce.co.nz/i/se5vk0nj.nx5.jpg)
(http://iforce.co.nz/i/2j0lvkzk.dsy.jpg)

Here's what i've come up with. Flat wooden block that another screws into. There's 4 screws so a jubilee clip can fit between them. I forgot to model the slot required. But it should give fairly easy adjustment in alot of directions (screw holes will be enlarged and washers used to give it some play). Shims can also be used for the other directions, and being square it should be easier to guess where to put them and how much to use. It should also be possible to adjust the thing without disassembling it.

I was wondering why I didn't do something like this the first time around, but then I remembered I didn't have a tablesaw back then and this would've been difficult to do well on the bandsaw.
Title: Re: Banjo Build
Post by: vtsteam on April 01, 2015, 08:14:24 PM
Simon, you're doing the right thing, making things easier on yourself for the future. You'll save this time and a lot more down the road, make better parts and reduce mistakes and frustration. Good investment! :thumbup: :clap:
Title: Re: Banjo Build
Post by: S. Heslop on April 02, 2015, 10:31:25 AM
Simon, you're doing the right thing, making things easier on yourself for the future. You'll save this time and a lot more down the road, make better parts and reduce mistakes and frustration. Good investment! :thumbup: :clap:

Yeah hopefully it works out. I try to make things as adjustable as possible now since expecting things to just work out never.. works out. One really stupid thing I did when building the sander was gluing the trunnions onto the table, and then epoxying threaded rod into the sides of the thing. So it's impossible to take the table fully off unless I want to break the glue joints. If I was doing it again i'd use knobs and threaded inserts. I suppose I could still do that but i'd rather not give myself more work.

Right now i'm waiting for glue to dry. I spend my life waiting for glue to dry. It's the real downside of working with wood (aside from the dust). Wish I had the forethought to do that last night. I've sharpened the bandsaw blade in the meantime and, even though I mangled alot of the teeth, it cut's like new.
Title: Re: Banjo Build
Post by: vtsteam on April 02, 2015, 10:55:48 AM
Depending on the job size and strength needed, I tend to use 5 minute epoxy for small jobs for just that reason. Big jobs, it's way too expensive. Same for highly absorptive jobs. Also it's not as strong as slower epoxies, and not entirely waterproof. But it is very useful in a lot of situations.

If the type of glue connection can use it, I also sometimes use contact adhesives, to speed up the work. Laminating sections of casting patterns is an example. Again, not tremendously strong unless the glueline surface area is high and stresses are low/area but certainly adequate for certain situations, and very fast.

I tend to back up weaker gluelines with fasteners -- they are fast and prevent shifting and splitting, and it doesn't take many to do that. It oftan also means the part can be used imediately in building up a structure, since the fastener is a clamp. Dowels can work as fasteners in that way, too, for an all glued structure. Treenails are the ultimate, that way.
Title: Re: Banjo Build
Post by: S. Heslop on April 02, 2015, 02:50:43 PM
More problems. I've ran out of 2 inch screws and need to buy some more, plus the forstner bit I used to originally drill holes at 19mm/ 3/4" is the one I'd turned down to 18mm when making that bike. So I either need to get a new forstner bit or make some new bushings at a wider outer diameter. Either way i'll have to buy something before I can continue.
Title: Re: Banjo Build
Post by: S. Heslop on April 03, 2015, 12:03:55 PM
Might as well continue with the theme of moaning about everything. Must've pulled my back somehow yesterday and had an awful nights sleep with it. Took some codeine and got back into the garage for a bit. I'd forgotten to record cutting the blocks so I'll probably make another one and record that after I get the sander back where it belongs since it's currently on top of the tablesaw.

(http://iforce.co.nz/i/uk41mtj2.rf4.jpg)

Got these bits on and close enough to parallel. Unfortunately it turns out today is Good Friday so no shops will be open to get some screws.

I'm thinking that while i'm at all this I might try make a new rail and spindle (or part of one) without using the lathe, to make a dedicated spindle sander update video. I know the rails could be made without a lathe since they don't need to be that accurate and can be scraped and filed square, but the spindle might be trickier. Tilting the drill press table to be parallel to the drill's spindle and fixing the steel bar on square might get it accurate enough to work.

I find update videos a little cheesy so I might put something else in too. Considering doing a segment on how I feel about 'taking care of tools'. Stuff like crashing a lathe or dropping a chuck onto the ways is worth avoiding, but you get people out there who fuss about things like using chisels to open paint tins, or a drill as an improvised mallet while it's already in your hand. It's not that interesting a video topic though.
Title: Re: Banjo Build
Post by: S. Heslop on April 05, 2015, 11:36:52 AM
(http://iforce.co.nz/i/3ifeoh3j.ib3.jpg)
Ground down a (supposedly) 20mm spade bit to cut a tight hole for the bushing.

(http://iforce.co.nz/i/2uigcli5.yjn.jpg)
Over-did it a little and it took alot of pressure to press the things in.

(http://iforce.co.nz/i/ekr04an4.gda.jpg)
Didn't check the drill press table before drilling the hole and it was a fair ways off of square, so it was alot of shimming to get this thing to slide. It's still fairly tight and could probably do with a bit more work. But if I remember right, it was never really that smooth a slide to begin with. It'll probably wear itself in eventually.

(http://iforce.co.nz/i/azsjfylj.2yq.jpg)
Pressing the second one in using a very long cheating bar ended up shearing the vise's screw off towards the end. Just means the vise has a smaller travel now, but I'm almost glad this happened. I never expected this vise to last very long, being a cheap one at reduced price from LIDLs. But 3 years of very heavy abuse (whacking it with a hammer n all) it's held up pretty well.

It'll give a lead-in if I do make that video segment about taking care of tools. If it was some swish expensive record vise i'd be compelled to take care of it, and probably not get as much use from it.

(http://iforce.co.nz/i/dpj5a4mk.wfx.jpg)
Anyways I drilled the second hole a ways out so it's going to require some fairly heavy shimming. I'm taking a break for now though.


I think all of this is proving that I was just very lucky the first time I built this.
Title: Re: Banjo Build
Post by: S. Heslop on April 05, 2015, 03:39:10 PM
Had surprisingly no problems getting that second thing on.

Little cousins came over and hung out in the workshop and helped out while I reenforced the wood around that pin that was coming loose and then reassembled the thing. That again was a hassle. The connection between the yoke and the windscreen wiper motor was slipping so I tried shimming it up to tighten the joint. Worked for a bit then came undone (which won't be too big a hassle to fix). But just before it came undone I noticed that the spindle was tilting back and forth as the motor went up and down; a problem that wasn't happening before.

It seems very sturdy trying to shift it about by hand but maybe the torque of the motor was enough to slide the new lower motor mounts back and forth. If that's the case then i'll probably put some plywood blocks on the front and backs of them to reenforce them in their position. Although at that point the design won't be so elegant and will look a mess. The other option might be to make some largeish washers to go under the heads of the screw that hold it on, so I can really tighten them down to try get it to grip. But that'll then probably compress the shims more and require more fiddling and adjusting.

It's a shame because I really thought I had it. I guess the good news is that the spindle is running very true and doesn't seem to be precessing or vibrating at all. I was worried adding that pin across it would throw the balance out.
Title: Re: Banjo Build
Post by: S. Heslop on April 06, 2015, 01:21:24 PM
Used some thicker and longer screws on the motor mounts and fussed with shims to get them really cranked down, since the smaller ones were stripping the wood. It slides alot smoother now than before too.

t=8m24s In this bit of the video you can see the windscreen wiper motor moving back and forth. I never got around to fixing that since it didn't seem to be causing any trouble but i'd noticed that the bushings in the crank arm are surprisingly worn and this probably didn't help.

(http://iforce.co.nz/i/d1dtpmbe.ud3.jpg)
Welded a brace on. 2mm steel with 3.2mm rods with a cheap buzz box. Unfortunately someone borrowed my better welding mask, took it to work, then got laid off so i'm using the rubbish hand visor that came with the welder.

I'm doing it outside since there's still piles of sawdust about to catch fire.

(http://iforce.co.nz/i/tepqp2m1.ylh.jpg)
Not the prettiest welds but they're plenty strong enough.

(http://iforce.co.nz/i/wdm10rcc.zfy.jpg)
To try get the motor to grip the yoke better I turned a thing. One part of making stuff that I find funny is trying to come up with names for all the parts. Got no idea what i'd call this though. An insert? A flange?

Whatever it's called, I cant mount it in yet since I've ran out of epoxy on a bank holiday Monday. So i've reached a dead end for today.

Continuing with the topic of abusing tools, I turned down this bedford socket so it could reach inside the part i'd made.
Title: Re: Banjo Build
Post by: bertie_bassett on April 06, 2015, 02:12:50 PM
I'm doing it outside since there's still piles of sawdust about to catch fire 

where's your sense of adventure??

looks like your making progress, im sure you'll get there in the end
Title: Re: Banjo Build
Post by: S. Heslop on April 06, 2015, 02:54:22 PM
I'm doing it outside since there's still piles of sawdust about to catch fire 

where's your sense of adventure??

looks like your making progress, im sure you'll get there in the end

The adventure in this case would be going down into the garage every half our to make sure no sparks snuck into a pile and left it smouldering for a while before it fully caught light. I have managed to set oily rags on fire before while welding though!

Thanks for the encouragement. I'm really wishing I just left the thing misaligned though so I could move on with the project. Turning the pot round was supposed to be the easy part!
Title: Re: Banjo Build
Post by: S. Heslop on April 07, 2015, 04:46:08 PM
(http://iforce.co.nz/i/bhhdyq2e.q05.jpg)

Got it back together for now. It was still acting funny but then I realised what the problem was; the crank arm was hitting the horizontal beam at the top of its travel. Helps show how strong those windscreen wiper motors are since it was flexing the whole plywood block that the motor is mounted to instead of stalling it. All that'll require is some adjusting of the yoke to fix it.

There's alot of little things here and there I could do to improve the thing too. I thought up a slightly better idea for the yoke part that i'm tempted to try, but I could get caught up in all this stuff if I let myself. If nothing else I might just update the cad model of the machine.

Looking at the video I took it looks like the thing I was trying to fix in the first place isn't aligned, it's now about as far out in the other direction. With the billions of shims I hope that trying to shift the thing parallel doesn't make the slide jam up. But hopefully it should be easier to do.

Also since this thing was about 99% fiddling I didn't record much of it. And I've neglected to take any clips of putting the shims in.
Title: Re: Banjo Build
Post by: sparky961 on April 07, 2015, 07:04:28 PM
I have managed to set oily rags on fire before while welding though!

A few months back I started a new job.  Within the first month on two separate occasions I set a rag on fire while welding.  Fortunately it was more funny than scary, but unnoticed in a home shop it could have been devastating.
Title: Re: Banjo Build
Post by: S. Heslop on April 08, 2015, 12:57:46 PM
Got the thing reassembled. Also put the sandpaper on with a thin layer of 5 minute epoxy. It's brittle stuff and the idea is that it should hopefully be quite strong in shear as it sands, but should peel off easily. I'll be replacing the paper when I finish sanding the drum, so I can use some finer stuff to get a smoother finish. So i'll find out if this idea works then.

(http://iforce.co.nz/i/nnqedaof.mej.jpg)

Not sure if I'll call this whole thing a success though. All I really did was broke everything and fumbled about for a week trying to get it back together. It's still out of alignment and I could try fixing that but... I don't want to end up stuck with another weeks worth of this bullshit.

I suppose I'll get this pot round first and then maybe fuss with the alignment.

At this point though this whole project has taken alot longer than expected (as usual) and i've got some essential stuff I need to get around to. So I might shelve it again after getting the pot round.
Title: Re: Banjo Build
Post by: Brass_Machine on April 08, 2015, 01:55:00 PM
...
Not sure if I'll call this whole thing a success though. All I really did was broke everything and fumbled about for a week trying to get it back together.
...

That's a line right out of my book! You are not alone...
Title: Re: Banjo Build
Post by: S. Heslop on April 11, 2015, 03:58:44 PM
Where abouts is a good place to buy high speed steel tool blanks? I've checked the usual places (arc euro and rdg) but they don't offer it in larger diameters. Cromwell tools does, but at 20 or w/e for the size i'm after that's quite pricey. Especially since I need a few

I'm trying to make some better wood lathe tools since the price of the tools themselves is incredible, and the profiles don't seem to be anything I couldn't grind and make handles for myself.

(http://iforce.co.nz/i/abhedskq.xrw.jpg)

Regular chisels don't give alot of leverage and i've had the tool dig in a couple of times. Plus they're going blunt very fast. The outside is fairly smooth already but it'd be a stupid idea to try do the inside interrupted cut with the same chisel.

Also I need to figure out better speed control for that drill. It has speed control but it's fussy, and won't stay at a steady speed. Might try a dimmer switch, but i'll have to check if they can handle the load.
Title: Re: Banjo Build
Post by: S. Heslop on April 11, 2015, 04:29:35 PM
Actually, forget that. Thinking about it I should really just shelve this project now so it doesn't distract me. I'm not a great multi-tasker.

If I was doing it properly, seriously trying to make a banjo, i'd probably be best off making some sort of lathe from welded steel and buy one of those x-y tables they sell for drill presses. But i've mostly been playing around with goofy ideas that haven't really worked out that well.

I've mentioned in the past about setting up businesses, but with those I was mostly playing around with the idea too. But since my brother got involved i've started taking it more seriously. We've been looking at renting units the last week and we're considering taking out a loan to pay for tools and vehicles. Fleshing out the business plan and all that.

So RIP the banjo, for now.
Title: Re: Banjo Build
Post by: vtsteam on April 12, 2015, 09:25:07 PM
Leaf springs?
Title: Re: Banjo Build
Post by: Will_D on April 19, 2015, 06:46:00 AM
What about 12" or longer files? Either big flat ones or big half round ones. They don't need to be new as its not the teeth you wants its a sharp end. So any old files from the 'bay or the boot would do.

Great quality steel and you could always reforge the ends to make V's and gouges. If you can't forge yourself find a blacksmith!
Title: Re: Banjo Build
Post by: S. Heslop on April 19, 2015, 08:59:03 AM
What about 12" or longer files? Either big flat ones or big half round ones. They don't need to be new as its not the teeth you wants its a sharp end. So any old files from the 'bay or the boot would do.

Great quality steel and you could always reforge the ends to make V's and gouges. If you can't forge yourself find a blacksmith!

That's a good idea. I might give it a try.
Title: Re: Banjo Build
Post by: awemawson on April 19, 2015, 09:02:51 AM
Beware that many modern files are only case hardened - not true of older ones
Title: Re: Banjo Build
Post by: vtsteam on April 19, 2015, 09:39:30 AM
I was wondering myself about using the steel in wde brick chisels for home forged tools, since they can be sharpened and case hardening would't work for that. They are usually much more substanial than wood chisels and there's a nice wide slab of metal there. Also big cold chsels found at tag sales sometimes.

I have had good luck forging, hardening, and tempering older leaf springs from junkyards. I don't know about whether newer ones are case hardened. Some are fberglass. :(

For anyone who wants to make their own woodworking and stone working hand tools, a must read is Andrew Weygers two blacksmithing books.
Title: Re: Banjo Build
Post by: awemawson on April 19, 2015, 10:30:39 AM
If you are prepared to forge it, rebar is usually hardenable, certainly ok for masonry chisels
Title: Re: Banjo Build
Post by: S. Heslop on April 19, 2015, 02:04:59 PM
Beware that many modern files are only case hardened - not true of older ones

I got some old one here, Made in Sunderland. They were throwing a whole bunch of worn files out at Tanfield Railway and I asked if I could have any sharp-enough ones. Wish I knew at the time that the steel itself was worth keeping, since there were alot of totally blunt files I left behind.
Title: Re: Banjo Build
Post by: S. Heslop on April 30, 2015, 04:04:21 PM
I spent a few days reading up on wood lathe chisels and didn't really find much information on how to handle heavy internal interrupted cuts. Plus with the whole arrangement not being too rigid to begin with it seemed kinda dodgy.

So I thought i'd try something different.

(http://iforce.co.nz/i/cxl5zvfg.vcp.jpg)
It's a wooden arrangement built similar to a metal lathe cross-slide. Alot of the details in this cad are missing since i'm probably going to figure that stuff out in person.

(http://iforce.co.nz/i/0jgnljat.vba.jpg)
Parts rough cut and arranged.

(http://iforce.co.nz/i/wdnm5n0r.pkl.jpg)
Used wood glue to attach the paper templates (I was going to mark it out properly but somehow all 3 of my tape measures have gone missing), and it was tough to get off with a chisel. So I tried just sanding it.

(http://iforce.co.nz/i/tn3dv3k2.lq5.jpg)
And... oh... looking at this photo, i've glued these parts on upside down. Hope that glue is still soft so I can separate them.
Title: Re: Banjo Build
Post by: S. Heslop on April 30, 2015, 04:17:10 PM
Could just barely separate them. I'll let the residual glue dry and send them through the drum sander tomorrow. I'm getting alot of use out of that machine, much more useful than the spindle sander.

Also I think I jumped the gun on declaring this project dead. Turns out trying to set a business up involves alot of waiting.
Title: Re: Banjo Build
Post by: efrench on May 01, 2015, 04:43:41 AM
Old planer blades are a good source of high carbon or high speed steel for making scraper type tools. Car shock absorber rods are usually HSS and can be ground into gouges.  Files are a bit iffy as they are prone to cracking.  Be sure to wear adequate face protection when turning.   Scraper tools should be ground with an included angle between 60 and 80 degrees. Use 60 degrees for softer wood and up to 80 for hard woods (hardness not type).

Putting longer handles on the tools will make them easier to control.  My main roughing gouge has a 36" handle.
Title: Re: Banjo Build
Post by: S. Heslop on May 01, 2015, 03:01:58 PM
(http://iforce.co.nz/i/au4s4g2q.jwd.jpg)

I think i've built something very silly.

Still thinking about how i'm going to do the toolpost. Adjusting the cut with the slots in the base were my original idea but i'd have to get it all aligned between each cut. Just advancing the tool in the toolpost would probably work alot better. Facing it with a bit of steel would probably also help, since I can see the tool wanting to squash the wood beneath it from the force of the cut.

Still no idea if this'll even work though, might not be rigid enough to handle the cutting forces (even if it's just cutting wood).
Title: Re: Banjo Build
Post by: RobWilson on May 01, 2015, 03:19:08 PM
Car shock absorber rods are usually HSS . 

You sure about that ?   :scratch:

Rob
Title: Re: Banjo Build
Post by: efrench on May 01, 2015, 10:09:47 PM
Car shock absorber rods are usually HSS . 

You sure about that ?   :scratch:

Rob

Yes.  It's easy to tell. HSS will create orange sparks when ground. High carbon steel sparks will be yellow.
Title: Re: Banjo Build
Post by: efrench on May 01, 2015, 10:20:55 PM
(http://iforce.co.nz/i/au4s4g2q.jwd.jpg)

I think i've built something very silly.

Still thinking about how i'm going to do the toolpost. Adjusting the cut with the slots in the base were my original idea but i'd have to get it all aligned between each cut. Just advancing the tool in the toolpost would probably work alot better. Facing it with a bit of steel would probably also help, since I can see the tool wanting to squash the wood beneath it from the force of the cut.

Still no idea if this'll even work though, might not be rigid enough to handle the cutting forces (even if it's just cutting wood).

I think you would be better off with turning the original toolpost 90 degrees and make a beefier tool that can handle a two or three inch overhang.  One easy to make boring tool for wood is to drill a hole in the end of a 3/4" mild steel rod and insert either a round or square HSS tool bit in it.  Secure it with a set screw.  The hole can be anywhere from 90 degrees to the axis to on the axis.  Broken endmills work well for this.
Title: Re: Banjo Build
Post by: S. Heslop on May 01, 2015, 10:39:52 PM
I think you would be better off with turning the original toolpost 90 degrees and make a beefier tool that can handle a two or three inch overhang.  One easy to make boring tool for wood is to drill a hole in the end of a 3/4" mild steel rod and insert either a round or square HSS tool bit in it.  Secure it with a set screw.  The hole can be anywhere from 90 degrees to the axis to on the axis.  Broken endmills work well for this.

That's not a bad idea. I'm not so worried about the tool itself having too much overhang though, and more concerned that the extra leverage will cause trouble with the fairly flimsy wooden arrangement.
Title: Re: Banjo Build
Post by: chipenter on May 02, 2015, 01:32:56 AM
I would use TC inserts just bolted onto a bar with a lever arangement for feed , there are wood turning chisels that take inserts available and they last for ages , 
Title: Re: Banjo Build
Post by: RobWilson on May 02, 2015, 04:04:14 AM
Car shock absorber rods are usually HSS . 

You sure about that ?   :scratch:

Rob


Yes.  It's easy to tell. HSS will create orange sparks when ground. High carbon steel sparks will be yellow.


Interesting , I will look into that , just cant see why they would use a tool steel in car shocker rods .


Rob
Title: Re: Banjo Build
Post by: DavidA on May 02, 2015, 07:54:31 AM
Efrench,

It's not that simple.

There are lots of steels that will produce sparks of this colour.

I spent the last seven years of my working life producing samples for spectrograph (and chemical) analysis. There was a lot of grinding involved in this.

We  had a few shock absorber shafts to check,  as I recall,  non of them were made from HSS. Just heat treated high quality steels.

I suppose one could test this by getting an old shock absorber shaft and trying to make some lathe tools from it. See how the edge holds up.

Dave.
Title: Re: Banjo Build
Post by: vtsteam on May 02, 2015, 12:46:28 PM
Now there's a practical suggestion.  :thumbup:
Title: Re: Banjo Build
Post by: S. Heslop on May 02, 2015, 02:03:31 PM
(http://iforce.co.nz/i/lrapsqh5.cfj.jpg)
Just going with this for the toolpost. Turned the thing by hand and it seems to be cutting okay.

(http://iforce.co.nz/i/slmmzlmf.zv1.jpg)
For adjusting the depth of cut I can just use this threaded rod with a couple of nuts on it, and a bit of trig, to tap the tool forwards in the holder. I'll probably be moving the whole thing forward a few times to reduce the overhang when roughing this out.

(http://iforce.co.nz/i/vc350gtt.0y1.jpg)
Need to deal with the runaway speed control next though. My first thought was dimmer switches but they're surprisingly expensive and I can't find any nearby rated at over 400w. I guess i'd need about 800 for this drill.

Wonder if it'd be possible to take the speed controller out of another power tool...
Title: Re: Banjo Build
Post by: Will_D on May 02, 2015, 02:17:17 PM
We use these to control out boilers in the homebrew world:

http://www.ebay.ie/sch/i.html?_from=R40&_trksid=p3984.m570.l1313.TR0.TRC0.H0.X3800w+dimmer.TRS0&_nkw=3800w+dimmer&_sacat=0 (http://www.ebay.ie/sch/i.html?_from=R40&_trksid=p3984.m570.l1313.TR0.TRC0.H0.X3800w+dimmer.TRS0&_nkw=3800w+dimmer&_sacat=0)

They really are rated at 3.8 kW and are pretty cheap (from China) or OK from the UK.

The heatsinks need to be earthed (to be sure to be sure) and will get hot if dimming  2.5 kW and above
[edit: fixed typo!]

HTH - Will
Title: Re: Banjo Build
Post by: philf on May 02, 2015, 03:13:27 PM
Simon,

Years ago I built a basic drill speed controller which worked very well giving a large speed range with good torque at slow speed and had very few components.

(http://listerengine.com/coppermine/albums/userpics/10017/BT151SpeedControl_zps48fcc314.jpg)

I used to be involved in making BT151 thyristors and still have a few somewhere if you fancy building one.  The BT151 would need a small heatsink.

I can't find the control - I probably binned it as most drills come with speed control as standard.

Phil.

Title: Re: Banjo Build
Post by: S. Heslop on May 03, 2015, 06:25:12 AM
Thanks for the offer and suggestion but I want to see if I can get this working with what i've currently got for now.

(http://iforce.co.nz/i/d5chtccr.je4.jpg)
I thought that maybe the runaway speed was caused by vibrations so I tried removing the trigger and mounting it to a board and using a cam to push it in. Unfortunately the speed controller is just garbage, and while it can start slower (but still fast) it picks up speed slowly till it's running full speed.

I think next i'll try taking the speed controller out of the jigsaw.

(http://iforce.co.nz/i/m3y1ntlk.ksk.jpg)
Turned a little bit with the runaway speed though. It's hard work turning the crank all the way in and out. I might just try autofeeding with the cordless drill once I figure the speed problem out.
Title: Re: Banjo Build
Post by: krv3000 on May 03, 2015, 06:27:22 AM
Hi I like the switch mod
Title: Re: Banjo Build
Post by: vtsteam on May 03, 2015, 08:18:13 AM
How about a belt to the outside of the banjo, since you've got that round? a vee belt will work on that much wood surface area without need for a vee. A small rod in wood bearings for an arbor (jackshaft) and a small vee-belt pulley between them at the other end. A couple of machinery bushings (stop collars) on the arbor to trap it. Chuck the arbor end. That takes the side load off the drill/motor.
Title: Re: Banjo Build
Post by: S. Heslop on May 04, 2015, 04:49:10 PM
Hi I like the switch mod

Me too, shame it didn't work!

How about a belt to the outside of the banjo, since you've got that round? a vee belt will work on that much wood surface area without need for a vee. A small rod in wood bearings for an arbor (jackshaft) and a small vee-belt pulley between them at the other end. A couple of machinery bushings (stop collars) on the arbor to trap it. Chuck the arbor end. That takes the side load off the drill/motor.

The outside isn't really round yet. I was going to try cutting the outside first, but decided it'd probably be better to try get the thing more balanced by cutting the inside first. Plus it'd get in the way when I eventually get around to cutting the outside. I did consider a jack shaft to reduce the rpm but that was starting to get complicated.

(http://iforce.co.nz/i/yuji3mxd.flo.jpg)
I ended up pinching the speed controller from the jigsaw. If it doesn't catch fire I shouldn't have any trouble putting it back when i'm finished. The drill still has runaway speed, but it's much more adjustable than just with the trigger, so i'm able to fiddle with it and the speed of cut so that it maintains a steady and slower speed when working.

(http://iforce.co.nz/i/pahohqej.pis.jpg)
Using the battery drill to control the cut. Much easier than the crank and it doesn't sway the slide like when cranking it.

(http://iforce.co.nz/i/nip5f45q.tkh.jpg)
Managing a fairly heavy cut, about 3-4mm.

(http://iforce.co.nz/i/sxjvs1z1.ckt.jpg)
It's leaving a fairly okay cut. Bit hairy on where its cutting into the endgrain but it isn't tearing chunks out and its nothing a bit of sanding can't clean up.

Had a bit of a weird day today and didn't get alot done. I probably could've cut more but at the time I was thinking I might regrind the tool to reach all the way to the end. But I just realised that I probably wont need to cut it all the way since it can be cleaned up with one of those flush cutting router bits.

Also, just for the record, i'm switching the thing off when fiddling with the speed controller since it's all very exposed. If it was a more permanent setup i'd have built an enclosure for it.
Title: Re: Banjo Build
Post by: S. Heslop on May 05, 2015, 05:03:56 PM
Damn thing seized up, then the nut the threaded rod was working against started spinning. Took it apart to see what the problem was.

(http://iforce.co.nz/i/f2jd5qil.1n5.jpg)

That's alot of filings for just moving the thing in and out about 15 times. The nut was really fused onto the bar and I couldn't get it off with it in the vise. My guess is either that the filings built up and clogged the nut, or the nut wore so much that what was left of the threads swaged into each other.

I'm just going to try the same thing again but with some grease and see how that works.
Title: Re: Banjo Build
Post by: S. Heslop on May 06, 2015, 12:33:04 PM
Tried John Mill's thing of squashing a nut into aluminium, but M8 was too much for my vise and it broke the screw. The screw had already broken at the tip and really I sort of anticipated this'd eventually happen, but i've been abusing the hell out of that vise since i've got a nicer one to replace it with. Problem with the nicer vise though is that I won't be able to abuse it so freely.

(http://iforce.co.nz/i/rn2uaxdb.gkk.jpg)
Plenty of grease. I'd expect the grease to just swell the wood, but with the layer of wax and not expecting this thing to last for long anyways I thought i'd try it.

(http://iforce.co.nz/i/4htlnrac.se2.jpg)
But...

(http://iforce.co.nz/i/dq1iijir.zym.jpg)
Inspecting the damage, it doesn't seem that the the tool moved in the toolpost as I'd imagined would happen, but the whole thing must've moved.

To be fair, before this happened the tool was digging in a fair bit. It was making unpleasant sounds, but I sort of just wanted to get the thing more or less to size. I think it was mostly the tool geometry at fault. I was being lazy in not wanting to regrind it into something more suitable. Although it's not a wholly rigid setup to begin with.

Shouldn't be a hassle to glue it back on at least.
Title: Re: Banjo Build
Post by: Will_D on May 07, 2015, 06:18:51 AM
Simon,

I really admire your ability to take some pieces of plywood and build machine tools that work.

And boy do you test them to the limit!

Keep safe and keep up the good work
Title: Re: Banjo Build
Post by: RussellT on May 07, 2015, 08:24:25 AM
Simon

I don't know how thick it has to end up but there seems to be a lot of material to remove.  Could you use a jig saw to take some of the wood out - if you can't find a long enough blade you could make an angled cut to remove some material.

The area glueing it to the face plate will become smaller as it gets thinner.  How about making some clamps around the edge of the faceplate, or even screwing the banjo on if the screw holes could be hidden later.

I'm following with interest. :thumbup:

Russell
Title: Re: Banjo Build
Post by: S. Heslop on May 07, 2015, 10:09:49 AM
Simon,

I really admire your ability to take some pieces of plywood and build machine tools that work.

And boy do you test them to the limit!

Keep safe and keep up the good work

Continuing the theme, the conveyor motor on the thickness sander stopped working. Got a surprise looking at the electronics, but it seems that the mosfet got hot enough to melt the solder on the leads attached to it and they fell off. Surprised it could even still work at those temperatures. I remembered I forgot to put a diode over the motor and I wonder if it's just inductive currents from the motor causing that, but it could be what bluechip suggested in that thread with the power supply being too crappy to keep a stable voltage to the rest of the circuit.

Simon

I don't know how thick it has to end up but there seems to be a lot of material to remove.  Could you use a jig saw to take some of the wood out - if you can't find a long enough blade you could make an angled cut to remove some material.

The area glueing it to the face plate will become smaller as it gets thinner.  How about making some clamps around the edge of the faceplate, or even screwing the banjo on if the screw holes could be hidden later.

I'm following with interest. :thumbup:

Russell

My experience with jigsaws and deep cuts in the past is that the blade tends to wander. I did think about ways to rough out the material (was considering trying it with a router, as dangerous as that may be. But I couldn't think of any ways that wouldn't end up being more work than just turning it off.


Anyways I got the board glued back on and drying now. I was shy with the glue since I wanted it to be easy to separate later, but it was perhaps too easy to separate...

Still trying to think of a good tool geometry. Having a back rake seems like a bad idea since that's what I had, and a side rake might work better but i'm worried that with all the backlash (theres alot!) it'll risk pulling the slide forwards and digging the tool in. I could try a shallow rake (or no rake) but with wood that'd probably leave an awful cut and risk pulling chunks out anyways.
Title: Re: Banjo Build
Post by: mattinker on May 07, 2015, 10:34:58 AM
Simon,

I really admire your ability to take some pieces of plywood and build machine tools that work.

And boy do you test them to the limit!

Keep safe and keep up the good work

Maybe Simon forgot to reply, Matias Wandell http://www.sentex.net/~mwandel/ has been an important influence, very interesting aproach to machines!
regards, Matthew
Title: Re: Banjo Build
Post by: Lew_Merrick_PE on May 07, 2015, 11:54:28 AM
Simon,

You are now finding out why I use the circular lamination approach to banjo shells.  The outer guide is the female piece cut-off from the tool blank first using a bandsaw (OD then ID).  By making the tool blank in "halves," the ID of the outer guide may be "opened" to access a drilled hole from which the ID may be bandsaw cut (and finished on a spindle sander).  The inner core is a male piece that is easily cut with a bandsaw and finished on a disc sander.

A tire from a 6 inch hand-truck tire is the "clamp."  I carefully trim and place the outer (really nice wood) lamination to the ID of the outer guide, trim & fit the next layer in to that, remove the next layer, slather up the ID of the (first) layer, re-insert the next layer, insert the inner core (with inner tube), and inflate the inner tube as the clamp.  Repeat as required until your desired thickness is reached.

Another advantage of this approach is that only the inner and outer laminates need to be "matched" and "pretty."  The "filler layers" can be whatever wood is structurally sufficient and inexpensive.  A fascia of "pretty wood" covers up the "filler layers" and, itself, is hidden by an appropriate edge binding.
Title: Re: Banjo Build
Post by: S. Heslop on May 07, 2015, 02:24:36 PM
The outer guide is the female piece cut-off from the tool blank first using a bandsaw (OD then ID).  By making the tool blank in "halves," the ID of the outer guide may be "opened" to access a drilled hole from which the ID may be bandsaw cut (and finished on a spindle sander).  The inner core is a male piece that is easily cut with a bandsaw and finished on a disc sander.

I don't fully understand what you mean. But either you've given me an idea or this is what you're saying; but I wonder if I could just make a plywood template for a router bit's bearing to follow, attached to the rough rim. Of course such a deep cut would be fairly dangerous (even if router bits of that length exist), especially with my crappy wooden router lift with questionable rigidity... Perhaps I could've routed each layer separate before glueing them together.

One thing that concerned me with laminate rims is the possibility of it warping. Since (as far as I know) there's no huge shaping after it's been glued up, and you've got a fairly damp thing soaked with glue, won't there be a fair bit of warpage as it dries? I assume that mustn't be that big of a problem since plenty of banjos are made that way, but it's still something I didn't want to risk having to tackle.


Anyways I ground up a tool bit without thinking too hard. I think I just ended up automatically making a bog standard turning tool with heavy rakes and reliefs.

(http://iforce.co.nz/i/42sljfbn.ddy.jpg)

I think trying to use that would be a bad idea since it's got more than a few ways it'd want to dig in.

So I figured that if I ground it again but with no (or very little) side relief, then that would prevent the tool from digging in too deep.

(http://iforce.co.nz/i/g3jctnty.0gp.jpg)

Title: Re: Banjo Build
Post by: Lew_Merrick_PE on May 07, 2015, 05:33:34 PM
Simon -- I start off with two blocks laid up as 8 inches X 16 inches X 4 inches.  I create mortises in between the outer area (16 inch OD X 11 inch ID) and at the center of the (7 inch OD) inner core that I will use to screw together (and release) the "halves" of the mold.  I then bore a (usually 1-1/2 inch) hole on the "inside tangent" of my 11 inch ID right on the (8 inch) "center mate."  I bore a (usually 1/4 inch) hole at the center of my block set to use as a "pivot" when cutting on the bandsaw.

I cut the (16 inch) OD, take the pieces apart to insert the bandsaw blade into the (1-1/2 inch) clearance hole, reassemble the pieces, and cut my (11 inch) ID.  I can now unscrew the batten/inserts in the OD ring and remove it from the bandsaw.

It is now trivial to cut the 7 inch OD on the inner core.  I then drill a (1-1/2 inch) hole approximately 1 inch inside of the (7 inch) ID.  This is to access the filler stem of the inner tube.  I then bore (approximately centered on the 4 inch thickness) a (roughly) 7/16 hole into that (1-1/2 inch) access hole for the filler stem itself.

Add a couple of "side plates" to cover the "gap" between the inner OD and the outer ID and you have a chamber that will support an inflated inner tube.  Lay-up the pieces as indicated in my previous missive.

When you are done, you can clamp the lay-up such that it extends a bit beyond the edge of the OD ring and hold that against a rip-fence of your table saw to get a nice, clean trim.

Does that clarify things?
Title: Re: Banjo Build
Post by: S. Heslop on May 08, 2015, 06:24:10 PM
(http://iforce.co.nz/i/xc12edt4.o4w.jpg)
Got it all back together, which took a while since everything was going wrong. Forgot if I mentioned it but the faceplate got knocked when the thing exploded, so I had to remake that part since the hole was warped and it'd become fairly loose. Had to turn that flat by hand since I could only drill an undersized hole, and the shaft was crooked when I hammered it in (kind of wish I recorded it all but it seemed boring at the time).

Got all ready to cut though and the drill seized up.

(http://iforce.co.nz/i/gbj5e54m.gvb.jpg)
The top hat part is stuck pretty solid. Too late to make alot of noise doing a postmortem, but I wonder if it managed to friction weld itself on. I'd actually made that top hat part myself since the original once (which appeared to be made from steel, but maybe it was a zinc alloy) was incredibly worn. I'll try find a new cheap drill to replace it at the boot sale on Sunday. Hopefully one with better speed control.

(http://iforce.co.nz/i/2hweftnw.gjf.jpg)
Anyways I had a go at cutting a bit turning the thing by hand, to see how the tool works. Cuts lovely and smooth going into the wood but was leaving some ragged stuff when going into endgrain. Perhaps it'll work better spinning at a higher speed.
Title: Re: Banjo Build
Post by: vtsteam on May 08, 2015, 07:43:44 PM
Simon there's a silver colored heavy duty oilite sleeve bearing material that could be mistaken for steel. Maybe that was the material your first bearing was made from.
Title: Re: Banjo Build
Post by: S. Heslop on May 17, 2015, 05:15:03 PM
Simon there's a silver colored heavy duty oilite sleeve bearing material that could be mistaken for steel. Maybe that was the material your first bearing was made from.

Yeah that seems likely. The shaft wasn't too worn if I remember right but the bearing was insanely so.

At the boot sale I managed to find a cheap drill that had the exact same problem with an extremely worn plain front bearing.

(http://iforce.co.nz/i/i0we3uex.y01.jpg)

Lots of chips. The new tool geometry needed a slight change to flatten the tip of it so it'd not leave the cut strands still attached to the wood. I'll have to remember to get a close up photo of that. The new drill worked fairly well, the speed control built in is much more adjustable than the first and didn't require any fussing, but since the drill is running in reverse the chuck tended to unscrew itself since there's no second left hand screw to lock the chuck on. Some locktite more or less sorted that out though.

(http://iforce.co.nz/i/z4bxvzq1.hsc.jpg)

Got the inside turned true-ish and sanded. I made a wooden set of inside calipers to try gauge the diameters, and according to those measurements the inside should be fairly parallel. It'll of course be easier to measure the outside diameter (via the circumference) to get that closer to parallel, then I can see how well those calipers worked for the inside.

(http://iforce.co.nz/i/iow3xmn4.hw1.jpg)

Got it partly set up for cutting the outside tomorrow. Too late now to continue making noise.

I'm also trying a new thing with also attaching the same photos for longevity. My usual image host went down for a bit a few days ago and it worried me that it might be gone for good.
Title: Re: Banjo Build
Post by: S. Heslop on May 20, 2015, 08:34:08 AM
More problems. It's easy to blame all this on bad luck but it's probably more just carelessness.

(http://iforce.co.nz/i/o0hscpuf.nn1.jpg)

I was getting a particularly rough finish on the outer diameter, and this probably should've tipped me off that something wasn't right. But after a few passes the tool dug in and stalled the drill, which was enough to cause something to start smoking inside of it. It wouldn't work at all after this.

(http://iforce.co.nz/i/i4t2kpez.xnj.jpg)
So I opened it up to have a look inside, and it turns out that it was just the brushes overheating. They must've swollen or melted the plastic housings since they no longer fit, and the wires had detached from them. I had to shave down some oversized brushes with a file to get them to fit. It's working fine now but i'm gonna give it some time to cool down fully.

It also gives me a chance to think about tool geometry again. My guess is that the large relief for the inside diameter meant that not much of the tool was getting supported against the workpiece. I'll probably grind the other end of the tool similar to the first but give it no end relief.

I am a little concerned that I might've overdone the cut though. What I really need for this is a pair of long calipers. I made a sort of giant scissor caliper from wood but it's all too flexible to feel at all accurate. I might make some sort of caliper extender for the digital calipers. Hopefully I haven't already overdone the cut though.
Title: Re: Banjo Build
Post by: vtsteam on May 20, 2015, 09:02:03 AM
Simon, just letting you know I'm continuing along with you here and reading every post. Not much to say as you're doing things I wouldn't do  :), but I have a feeling you're going to be successful in the end, after whatever trials and tribulations occur. And I expect to learn as much as you do in the process! Be careful, stay safe -- other than that, it's all learning.
Title: Re: Banjo Build
Post by: awemawson on May 20, 2015, 10:47:31 AM
Simon, yes just like Steve I'm following and silently encouraging you. What wall thickness are you aiming for? I imagine it'll get rather wobbly if too thin.
Title: Re: Banjo Build
Post by: S. Heslop on May 20, 2015, 01:22:59 PM
Simon, yes just like Steve I'm following and silently encouraging you. What wall thickness are you aiming for? I imagine it'll get rather wobbly if too thin.

I'm going for around about 20mm, but ideally it'll be as thick as possible.

From what I understand, most of the force (from the strings) in a banjo is taken by the coordinating rod(s) that go through the rim. So you can get away with it being fairly flimsy.


I made that caliper extender. It's kind of goofy.

(http://iforce.co.nz/i/45b1ba5o.xz0.jpg)
It would've been more rigid with the 'rods' running in line with the blades rather than perpendicular to them, but it's useable as is. I just didn't think to do it that way till after. Seems repeatable to about .1 of a mm at least and that's good enough for wood. Also with the rods not being in line it's not really reading millimeters but it doesn't really matter since I just want to get the sides parallel.

(http://iforce.co.nz/i/rthl2wwe.e5s.jpg)
Here's the wooden thing I was trying to use before.


Also I appreciate people posting but don't feel you have to!
Title: Re: Banjo Build
Post by: awemawson on May 20, 2015, 01:50:58 PM
I know zilch about banjo's, but I always imagined that the 'drum' was laminated up from thin veneers making in effect a custom plywood 'short tube'.

Now other string instruments that I have examined have deliberately thin walls ('cellos, violins and violas) so to me 20 mm seems extremely heavy - but then as I say I know zilch about banjos !
Title: Re: Banjo Build
Post by: S. Heslop on May 20, 2015, 02:43:50 PM
I know zilch about banjo's, but I always imagined that the 'drum' was laminated up from thin veneers making in effect a custom plywood 'short tube'.

Now other string instruments that I have examined have deliberately thin walls ('cellos, violins and violas) so to me 20 mm seems extremely heavy - but then as I say I know zilch about banjos !

Most banjos are made that way but some are made from block rims like this. I don't think there's anything wrong with building them the other way, but I didn't have a drum sander at the time to easily make the veneers.

Violins and guitars do have fairly thin wood with bracing to strengthen it, because the vibrations from the strings are transmitted to those surfaces to make the sound (I guess the bigger surface just moves more air). Boy i'm having a hard time wording this elegantly. But in a banjo the skin head vibrates to move the air.

Guitars always amaze me with how they can stand the force of the steel strings considering how thin all the wood is.


Actually the main reason I wanted to build a banjo this way was because I thought it'd be nice to make some fancy patterns out of wood for the sides. The frame thing in this drawing was for a zither style banjo I was trying to make, although I thought i'd best make a regular old banjo before trying anything fancy.

(http://iforce.co.nz/i/mwexwlx5.ycn.jpg)

If you look up segmented turning you can find all kinds of fancy patterns used mostly for vases and bowls. It requires some pretty accurate cuts and alot of work fitting it though, and with my crap tablesaw it'd be difficult to achieve. I couldn't even cut a six sided thing without large gaps.
Title: Re: Banjo Build
Post by: S. Heslop on May 21, 2015, 02:45:25 PM
(http://iforce.co.nz/i/4v25qf1o.hxz.jpg)
(http://iforce.co.nz/i/5n0xztfw.ga3.jpg)
Amazing what a bit of sanding can do. It's to size now with about .6mm taper end to end, and that's good enough for me. Those visible gaps are filled with glue unfortunately, so I don't think I can fill them. But they'll probably be alot less noticeable once all the hardware is attached. I could also place the worst ones where the neck joins.

(http://iforce.co.nz/i/4fc134ai.nwt.jpg)
Started turning the inside, but I didn't feel wholly comfortable doing this. Had a couple of minor gouges before deciding that I was risking making more problems for myself (if not my safety). I then fiddled with router bits for a while, replacing the bearing on one with a bigger bearing. Although the bearing I replaced it with was too big, and I figured it'd probably make more sense to just turn a sort of washer to fit over the existing bearings.

I need to think a bit about what i'm going to do next though. Fancy banjos have tone rings installed, which come in all kinds of ridiculous styles, the simplest being a bit of brass wire or rectangular section set into the top. I think the idea with the tone ring is to have the skin resting on a hard surface so it absorbs less energy. The idea with the apple wood surface is that it's a fairly hard wood and might work by itself, but i'd want to shape it into an inward taper.

If I do go for bare wood I should be able to shape it with a selection of router bits rather than on the lathe. Although i've noticed that the apple wood is awkward to cut so I'll have to test a spare bit (hope i've got a spare bit!) before I risk ruining the rim.
Title: Re: Banjo Build
Post by: S. Heslop on May 21, 2015, 05:38:34 PM
(http://iforce.co.nz/i/pctib2f4.2sw.jpg)
Routed the taper with this conical bit. Also did a fairly large roundover, larger than i'd have liked but it's the bit I had and the cone didn't reach far enough in.

(http://iforce.co.nz/i/zfnmpjc2.ynj.jpg)
Sanded.

(http://iforce.co.nz/i/qllqkrrc.5uo.jpg)
Separated.

(http://iforce.co.nz/i/011jjcjy.vti.jpg)
Flush trimmed the remaining bits inside. Always surprises me how accurate this bit is since it came in a cheap set.

(http://iforce.co.nz/i/ndip2cgq.10j.jpg)
Trust a camera and harsh lightingn to show up all the blemishes.

(http://iforce.co.nz/i/ykyczy1i.eot.jpg)

Gotta finish up the bottom since it's still got paper stuck to it. I forget what the max depth on my drum sander is but hopefully i'll be able to just send it through that. Although there's not alot of contact area with the conveyor with the fairly hard apple, so it might be better to just glue a bunch of sandpaper to a board and rub it against that for a while.

I think i'll save drilling holes in the thing till i've made the hardware to attach to it. I know how i'm gonna make the hooks and nuts since I made 50 of them in the past for this absolutely ridiculous (but pretty) rim.

(http://iforce.co.nz/i/5yw0ypod.y4b.jpg)

But the L shoe brackets seem like they might be tricky without a mill. I had the idea in the past that i'd try lost wax casting them but since i've yet to successfully cast aluminium i'm not gonna try brass.

I might just have to spend a day making them the hard way with files. I'm gonna aim for about 24 hooks and nuts around the rim so that's not a huge amount for a one-off.
Title: Re: Banjo Build
Post by: S. Heslop on May 21, 2015, 05:51:36 PM
Oh I tend to forget that I have a die grinder now. Found some carbide burrs at a boot sale last year and a 'laminate trimmer' I bought turned out to just be a die grinder with a plunge base. That'll probably make life easier.

Another thing I might be able to do is make most of the shape and drill the holes into a long bar, then cut sections off and tidy them up with a file. With it in a long bar I could also possibly rough the concave material out by putting a burr in the router table and making alot of passes.

The problem is is that I don't find the idea of sitting down for a day and doing it the obvious way particularly exciting. I'd rather spend weeks like I did with the rim in trying to find a 'clever' solution that will most likely backfire.
Title: Re: Banjo Build
Post by: vtsteam on May 21, 2015, 05:52:08 PM
Hey, it's looking like the bottom of a banjo!!! :thumbup: :clap: :beer:
Title: Re: Banjo Build
Post by: S. Heslop on May 21, 2015, 06:22:12 PM
Hey, it's looking like the bottom of a banjo!!! :thumbup: :clap: :beer:

Thanks. And not a moment too soon.

I really hope the rest of it doesn't take me over three months.
Title: Re: Banjo Build
Post by: S. Heslop on May 22, 2015, 03:54:47 PM
Haven't done much today in the garage. But I did test that burr idea.

(http://iforce.co.nz/i/kny0ebbj.ury.jpg)
Seems to work fine. I tried it first with aluminium and it clogged the burr in seconds, but I then remembered I had a square bit of brass (about 1/2" wide). Depth of cut is about 4mm. The cut was made fairly fast and the brass heated up a bit but not to the point that it hurt to touch. So I think this idea seems fairly viable for brass at least. Possibly cast iron too, and anything where the chips aren't gonna clog the burr.

The only concern I have is the brass chips falling into the router below. I might try cover the vents (will still have to allow airflow).

While waiting for a chance to buy the brass required I'll probably make the hooks and nuts.
Title: Re: Banjo Build
Post by: NormanV on May 22, 2015, 04:02:26 PM
I've been following this with interest, I've made a Ukelele and a rough Guitar. I have an ambition to make a proper Guitar. What is the skin made from?
Title: Re: Banjo Build
Post by: chipenter on May 22, 2015, 04:24:45 PM
TCT router bits work well on aluminum spray the cutter with wd40 to stop a build up .
Title: Re: Banjo Build
Post by: S. Heslop on May 22, 2015, 04:47:28 PM
I've been following this with interest, I've made a Ukelele and a rough Guitar. I have an ambition to make a proper Guitar. What is the skin made from?

Mylar plastic as far as I know. Some folk like to use calf or goat skin for an 'authentic old time tone' but I think that's silly. Skin heads tend to change tension with humidity changes and can sometimes burst from it, and they're awkward to fit from what i've read. I did consider getting some skin for that rim with the 50 hooks, since there wasn't alot of space between the rim and the hooks to fit the rim of the head. I ended up filing notches into it to get it to fit.

I also tried looking up using plastic sheet as a head material but couldn't find much information on it other than a few failure stories (mostly with it stretching over time until eventually breaking). Didn't fancy experimenting.


TCT router bits work well on aluminum spray the cutter with wd40 to stop a build up .

I'm concerned this router table won't be at all strong enough for any serious cutting forces. I figured that since I can control a burr with my arms no problem it won't have too much force to deal with.
Title: Re: Banjo Build
Post by: chipenter on May 23, 2015, 02:33:50 AM
I have cut ally with a circular saw a planer and a router , no table or bench on site you don't have to cut it all out in one cut .
Title: Re: Banjo Build
Post by: SwarfnStuff on May 23, 2015, 03:32:42 AM
This has been and still is a fascinating thread. Thanks for posting.
John B
Title: Re: Banjo Build
Post by: S. Heslop on May 25, 2015, 01:14:47 PM
This has been and still is a fascinating thread. Thanks for posting.
John B

Thanks very much!

I've been hesitating to do much lately until I know what i'm doing. But I think i've finally got the general sizes and shapes of the hooks, nuts, and brackets figured out.

I dug out all the junk I used to make those 50 hooks a few years ago.

(http://iforce.co.nz/i/5mfzm0ji.sif.jpg)
On the left is a test hook with a wider angle than what I used in the past. Then next to it is an aluminium block used for holding the hooks in the lathe so I could trim them quickly. Then is a reshaped chisel to act as the punch for the die on the right. The small slug of steel is something new that I've put into the middle of the die to limit the depth that the brass can go, so I can adjust the angle and hopefully keep it consistent.

(http://iforce.co.nz/i/lbnrpcoi.d5x.jpg)
Closeup of the fixture. Not much holds it in but the slight wedge where the short end of the hook sits. You can see a flat spot on the brass wire from the punch, there's one on the other side too. The hooks on an old banjo I was looking at a while ago had the same flat spots and i'd assume they used a similar method to produce them as I did.


I'm still hesitating to go full steam ahead and make all the hooks I need (and a few spares), since there's still a bit of doubt as to if i'm getting the dimensions right.
Title: Re: Banjo Build
Post by: S. Heslop on May 25, 2015, 04:36:22 PM
(http://iforce.co.nz/i/0eulj12n.kaz.jpg)
Cut the rods to length. I need to clean my lathe at some point. The chuck isn't holding the rods, it's just at the end of its travel so I can pull the full rod out to touch it, and its then backed off a bit before cutting so it doesn't get in the way.

(http://iforce.co.nz/i/5dpx3aop.f1v.jpg)

Next I need to thread them. My 4mm die came with a very cheap set from Lidl's, and the 4mm die unfortunately cuts noticeably undersize. I'm considering ordering a better quality one so my threads look a little less dorky. An M4 die costs 25 from Cromwell tools though so sod that. I might try getting one from arc euro trade, although it won't let me see estimated delivery times until I put my credit card details.

I think i'll check a couple of local hardware stores before ordering one for delivery. I'm impatient!
Title: Re: Banjo Build
Post by: DavidA on May 26, 2015, 06:05:48 AM
Just wondering,  Would it be easier to thread all those rods using a tailstock die holder before bending them ?

Dave.
Title: Re: Banjo Build
Post by: Fergus OMore on May 26, 2015, 07:57:27 AM
If your cheap Lidl die is cutting too much( and Lidl dies are only for restoration work) you can refresh the die.

Frankly, you have already entered into a discussion here about making a set of dies etc. in - in this case- gauge plate. If it were me, I'd check how corresponding tap behaved and if it needed reducing in size, it would be a dead easy task.

Yes? It is what we Geordies called in the Pitmatic- ettling

Regards

Norman
Title: Re: Banjo Build
Post by: S. Heslop on May 27, 2015, 04:55:33 PM
I could've sworn I made a post last night about this. I must've forgotten to actually post it after previewing.

Decided to just use the die I have after remembering the prime directive; keep it simple. Doesn't cut as undersized as I remembered.

(http://iforce.co.nz/i/nsvltzqs.lvt.jpg)
The die is pushed forwards with the face of the chuck. There's a steel slug held in it that stops the tailstock when it hits the bar, and the die starts moving away from the chuck. The lathe is reversed when this happens. My reactions aren't great but it kept the threads within about a millimeter's difference.

(http://iforce.co.nz/i/q5jazkmq.tlj.jpg)
All marked for the bend.

(http://iforce.co.nz/i/vkh3pabu.3ow.jpg)
And bent.

(http://iforce.co.nz/i/0tir0m3h.aew.jpg)
I thought i'd get away with bending them all at once with the shallower bend than last time, but this one broke. It was a rod that span in the lathe chuck when the die got clogged with chips (forgot to blow them out) so perhaps that work hardened it.

(http://iforce.co.nz/i/3fgdhc5i.3zv.jpg)
Annealing them part way through solves the problem.


Today I started cutting the front of them.
(http://iforce.co.nz/i/pwp5joln.4ki.jpg)

(http://iforce.co.nz/i/redwd2cg.xxm.jpg)
Started keeping them in these drawers too since they were starting to get lost.

Tomorrow i'm going to buy some brass for the L shoe brackets, and also a new length of stainless for the tension hoop since the steel I bought previously was 3mm thick when I really want 5mm.
Title: Re: Banjo Build
Post by: S. Heslop on May 28, 2015, 07:28:04 AM
Finished up the hooks for now. Gotta polish them but I think I might go all out with a buffing wheel. I'm wondering what are the chances of the sharp edges of the hooks getting snagged on a mop? I was thinking I could make a handle to screw the hooks into to get more of a hold on them, but then I also think that it's just more mass to get thrown if or when they do snag.

(http://iforce.co.nz/i/fqawg5gp.tzi.jpg)
You can see how inconsistent they are. I thought of a way to make the hooks more consistent but I think the way I did them is pretty fast. It took me a while because i've spent the last few days helping look after a baby. Babies are hard work!

The inconsistency might bother me enough to make me trim the obviously long ones but I'll wait till it's assembled before worrying about that.


Also made a carriage stop to help with making the nuts. I've wanted to make one for years but was saving it for when I eventually get a milling machine. I think in the past for the same job I just set the compound to 90 degrees and moved that back and forth, but it's fairly slow and I don't fancy taking chances with my ability to count the turns.
(http://iforce.co.nz/i/t4pre0ml.w3g.jpg)

It's ugly as hell but it should work.
Title: Re: Banjo Build
Post by: vtsteam on May 28, 2015, 08:55:18 AM
You're coming along quickly Simon, particularly with a baby to look after! I didn't entirely understand how the threading die operation in the lathe is set up and works, but it clearly did work well.  :thumbup: :thumbup: :clap: :beer:
Title: Re: Banjo Build
Post by: S. Heslop on May 28, 2015, 02:21:04 PM
The tailstock isn't... whats the word... clamped to the ways. Locked to the ways?

Anyways i'm just pushing it along with my hand to put pressure on the die, which starts threading the bar under power, and I keep some pressure on to keep the die fairly flat as it continues threading.

The tailstock chuck is holding a bit of steel bar, which I set to a specific depth within the chuck so that when the threads are completed the end of the brass rod contacts that bit of steel bar inside the chuck and prevents the tailstock, that im pushing, from continuing to move forwards. Meanwhile the die can continue moving forwards, and as soon as I notice this I set the lathe into reverse so it backs the die off.

The die holder contacts and slides along the lathe ways to 'drive' it. I remember when I first did this I thought i'd try and be all safe and proper, and turn the lathe chuck by hand using the chuck key, but quickly found out that it was incredibly slow and hard work.


The threading was fairly accurate. Not exact but more than close enough. The inaccurate step was putting the bend in. I did think for a while about putting some sort of stop to butt the bars against for putting the bend in, but then realised that I didn't know where to position the chisel. I think it would work alot better with a press. Perhaps I could've made some sort of arrangement to use the vise for pressing.
Title: Re: Banjo Build
Post by: S. Heslop on May 28, 2015, 04:42:11 PM
Oh also it's my brother's baby so it's not a full time job, and i'm mostly just helping our mom out. She's just learned how to crawl very fast and it's quite frightening! Still alot of work only as part time.

Got set up to cut the nuts.
(http://iforce.co.nz/i/1txt03gk.4dg.jpg)
Using the turret tool post with the indexing feature, 2 profile tools, and the parting tool. The procedure this time is to screw the tailstock to the end of its travel and pull the bar out till it touches, then screw the tailstock back so it doesn't get in the way. Move the lathe to the right carriage stop then start with the profile tool to cut the 'chamfer' part in the middle, then turn to the profile tool to cut the round part. The round profile tool is kind of pushing it with what this lathe is capable of. Then a tickle with emery before moving the carriage to the left stop and parting it off.

There's some of those drawers under the lathe to catch the parts so it doesn't get lost into that mess I really aught to clean up. Not a fan of cleaning this tiny lathe since it more or less requires scooping the greasy crap with my hand out of the small space, then it gets all over the bench in front which has to be cleared off of the clutter so it doesn't get buried under the swarf.

(http://iforce.co.nz/i/aqqndihm.ifv.jpg)
Right hand carriage stop is just the carriage lock. I figure it won't have any problems with swarf getting in the way of it and the carriage like it would on the left.

(http://iforce.co.nz/i/dnfcs0x3.pbd.jpg)
Cutting the rest tomorrow. They're about 16.4mm long within about .1mm. I made an error on the lower left one, forgetting to index the turret and trying to part with the form tool since I was distracted with filming. And I kinda like the way it looks. I'm considering making the rest in a similar way.

When I made them the first time I drilled the holes in them during this step too, also did part of the profiling with a file and they all came out wildly different. I guess it has that 'hand made' quality but I think they look a mess. Anyways the drilled hole tended to drift after a few were made and needed to be started again, so i'm planning to just drill the holes and tap them as a separate process.

Also the rounded bottom isn't entirely decorative, and is more to stop them from digging into my thighs as much when playing the banjo.
Title: Re: Banjo Build
Post by: S. Heslop on May 29, 2015, 04:32:13 PM
There was nothing thrilling about this drilling~♫

(http://iforce.co.nz/i/52o1aiip.ad1.jpg)
It was a long process, and so were some of the previous ones, but what made this one especially tedious is that it would've gone so much faster with a camlock tailstock and a keyless chuck. Almost all of the time spent was undoing the tailstock screw.

(http://iforce.co.nz/i/klxvfvsm.neo.jpg)
Got 28 done. Unlike previous steps i'm not compelled to finish off the spare ones since it didn't use a fancy setup. I can just make another one from the few unfinished spares if something goes wrong.

(http://iforce.co.nz/i/lkuqxyut.pkx.jpg)
At first I was drilling a 4mm deep clearance hole above the threads, since it looked neat. But I realised after doing a few of them that way that it was hard to tell the difference once screwed on.


Next I've got to polish them. Still waiting for the brass to make the shoes. I've got no real polishing equipment and i'm considering trying to make my own mops by stitching together a bunch of old clothes. The other alternative would be to try tumbling them with some builder's sand. Not fussed about getting a high shine or anything since brass eventually tarnishes and looks like crap anyways.
Title: Re: Banjo Build
Post by: vtsteam on May 29, 2015, 04:39:05 PM
I was sorta thinking of a banjo as a woodworking project, but I'm starting to think it's metalworking project with some wood bits attached! Keep up the good work!  :thumbup: :beer:
Title: Re: Banjo Build
Post by: S. Heslop on May 29, 2015, 05:00:42 PM
You could always just buy the hardware ready made.  The hooks and nuts are about 1 Canadian dollar each. Although the shoes are $4.

Boy that's almost $160 for a 28 hook rim, but it probably isn't too far off the materials cost. 28 hooks is also way more than you need, I just think they look nicer with more.

That 12" rim banjo with 50 hooks is very silly though. The big problem with that many hooks is that there's hardly any tension on each individual hook. So the nuts tend to work their way loose. I read that there was a period of history where banjos underwent a hook war because, like with everything else, the bigger number means a better product. Supposedly they got up to 60 hooks on an 11" rim before people realised how ridiculous it was.
Title: Re: Banjo Build
Post by: S. Heslop on May 31, 2015, 03:42:54 PM
Knocked the edges off and shaped them a bit with some emery cloth stuck to a bit of wood.
(http://iforce.co.nz/i/i1jnctvf.eyv.jpg)

(http://iforce.co.nz/i/orupw02w.i1c.jpg)
I was planning on making some wheels as an excuse to use the sewing machine, but I was looking for the compounds and the only local place I could find that sold them was Halfrauds, who sold them in a kit with some tiny wheels and an arbour. I thought they worked pretty well though, the arbour had a left hand screw so it didn't loosen itself when rotating in a drill chuck.

Maybe Cromwell stocked them but it's a bit awkward to get to.

(http://iforce.co.nz/i/vd0nt32j.yk4.jpg)
The sides of my fingers are also nice and shiny.

(http://iforce.co.nz/i/23ourkrh.j5o.jpg)
Made the handle to hold the hooks but I just found it awkward. With a bit of threaded rod in the end it could hold the nuts, but a problem is that the threaded rod tends to come loose. I'm waiting for the loctite to dry before finishing the nuts. If that comes loose i'll just turn the other end and make the threads one piece.

The sad thing about getting brass this shiny is that it's not going to stay so for very long. It's tempting to lacquer them but then that'll probably wear off and look tacky.
Title: Re: Banjo Build
Post by: Fergus OMore on May 31, 2015, 04:09:45 PM
From where I sit might I answer a couple of issues.

The first is that mop cloths are usually stapled together because unless you have a boot patching machine or better, you'll bust a normal domestic machine.  I did tent making  or more correctly, repairs in canvas tents for the Scouts in Workington. You need saddle making needles and protection for your hands. See a sailmaker - like Tommy Owen. I think that the old firm is still around somewhere.


As far as brass lacquer is concerned, my daughter has just phoned us to say that she has bought a piano. Her Mum is going to die just yet and she will not the 7/8th Bluthner Grand yet. Tough but it poses the point that the Bluthner has its second coat of lacquer - since 1911.

Good lacquers are still available  for Saxophones and so on and Ferries of the USA are still the best although people like Windcraft in Cambridge are pretty good.
My mates DO wind instruments and I have lacquer but that is not for general exposure.

Ferries cat. is compulsive reading, by the way.


Norman
Title: Re: Banjo Build
Post by: S. Heslop on June 01, 2015, 12:41:44 PM
(http://iforce.co.nz/i/1okzkqtx.wkh.jpg)
Buffed nuts. There's still some scratches on the sides of them from where I gripped the hex bar with the lathe chuck. I think to remove that properly I should've gave the 6 sides a quick rub on some emery cloth. But alas~

(http://iforce.co.nz/i/2adllyfj.z5i.jpg)
Lined their tray with felt to hopefully protect them a bit. Not that it matters too much if they get scratched. A few of them are already a bit mangled from slipping off the buffing wheel and getting pushed into the rotating drill chuck. They also have a bit of scub left on them but i'm saving removing that for when i'm about to actually install them. I don't think it'll do any harm being left on till then.

Still waiting to get a call about some metal arriving in stock at a place to make the shoes. I hope they haven't forgotten about me! In the mean time I might start working on the neck.
Title: Re: Banjo Build
Post by: vtsteam on June 01, 2015, 01:43:53 PM
They look dang purty!  :bow:  :beer:
Title: Re: Banjo Build
Post by: S. Heslop on June 01, 2015, 01:50:38 PM
Thanks. I wish I wasn't lazy and took some before and after pics of the red and blue buffing compounds. Because the red makes them shiny, and I was thinking of stopping at that point and decided to buff it with the blue mostly to get the bulk of the grease off. Then I noticed that it does enshine them further. It's funny that it's all relative but I thought they were real shiny with just the red.

I think I now understand how people get obsessive over finishing.
Title: Re: Banjo Build
Post by: micktoon on June 01, 2015, 05:58:04 PM
 :proj:hi Simon, they look the dogs bollocks to me  :bow:, I thought you gave up and bought some when I saw the top photo  :drool:
 Cheers Mick
Title: Re: Banjo Build
Post by: S. Heslop on June 02, 2015, 10:34:29 AM
:proj:hi Simon, they look the dogs bollocks to me  :bow:, I thought you gave up and bought some when I saw the top photo  :drool:
 Cheers Mick

I'm glad I decided to buff them properly instead of doing a quick rub with brasso like last time.

Also sod wood. I got a bit of meranti, 45x95mm, and in my plans I had it drawn up as 55x95 which was just big enough to make the banjo neck from. Turns out though that I was assuming i'd be able to get a bit of contrasting wood (maybe maple) at some point to make up the extra width, which i'd forgotten about. So I've been spending a while trying to think of how I can make use of this wood by itself but it might just be too narrow to do anything with, mostly due to the whole grain thing.

So I guess the neck is now postponed too due to material shortages too. The wood is also about as far from quartersawn as you can get, with the gain running diagonal. It seems to be a fairly stable wood besides that though so I think when I do laminate the neck i'll just arrange it so the grain is mirrored. I suppose I could try working on the truss rod in the meantime.
Title: Re: Banjo Build
Post by: vtsteam on June 02, 2015, 10:47:15 AM
Wish you were closer Simon. I could give you some hard and soft maple, cherry, black and yellow birch, beech, ash, basswood (lime), red oak, or white pine for your banjo, since they all grow here. I imagine shipping is prohibitive. Most hardwoods are about 4 pounds (2 kg) a board foot (300x300x25 mm).
Title: Re: Banjo Build
Post by: S. Heslop on June 02, 2015, 12:02:04 PM
Wish you were closer Simon. I could give you some hard and soft maple, cherry, black and yellow birch, beech, ash, basswood (lime), red oak, or white pine for your banjo, since they all grow here. I imagine shipping is prohibitive. Most hardwoods are about 4 pounds (2 kg) a board foot (300x300x25 mm).

From what I read online, Canada seems to be wood paradise. I don't think there's enough people interested in woodworking over here for many places to stock non construction lumber.

Started on the truss rod. I'm going for this style of rod since it seemed easiest to make.

(http://iforce.co.nz/i/xh4axloy.oht.jpg)

6x12 brass was cut off.

(http://iforce.co.nz/i/ejobbtth.tyj.jpg)
And filed close enough to square.

(http://iforce.co.nz/i/ez5f1fjn.t52.jpg)
And drilled. I got it square by just butting it against the drill bit in the vise. This vise is terrible and came with one of those things that're supposed to turn your hand drill into a drill press, which I got on offer to make a tapping stand out of. I was deathly afraid of breaking taps at one point since you hear alot of stories, but it's something i've yet to suffer. Anyways I keep thinking I should get a better drill press vise some day, but I also keep telling myself that a milling machine (that i'm totally definitely going to get some day) would make it redundant.

(http://iforce.co.nz/i/ikbo3wt4.p03.jpg)
And that's them finished. I had to tap from both ends since my tap was just barely too short, but left enough of a faint tap to get it lined up from the other side. One block has a 4mm hole and i'll secure the rod with a couple of nuts most likely. The real truss rods use a left hand thread to get the thing together, but I don't have any left hand taps or dies.

And now i'm back to having nothing to do. I guess I might start figuring out how i'm going to make the tailpiece. I've made simple ones in the past but for this I thought i'd try something a bit more fancy.
Title: Re: Banjo Build
Post by: S. Heslop on June 04, 2015, 03:37:11 PM
I just remembered while riding the bus that I have a piece of a (what I assume to be) walnut counter top, about 22mm thick. I can laminate the neck using that. I've got some sort of lung infection though so the last thing I should be doing is breathing sawdust, even with a mask some gets through.

The walnut and meranti look kinda similar though, so it's gonna be a silly looking neck, but I can live with that.

I'm also reading up on making rasps so if I get the neck laminated before starting that it'll give the wood time to stabilize.
Title: Re: Banjo Build
Post by: S. Heslop on June 05, 2015, 10:01:45 AM
(http://iforce.co.nz/i/oioekhfg.up4.jpg)
Split boards and tidied them up.

(http://iforce.co.nz/i/kkxruymy.dx5.jpg)
At 52mm it's about wide enough for a neck, but will need some extending at the peghead end, also there's some gaps and the jointing isn't perfect since my jointer sucks. It's not glued yet.
Title: Re: Banjo Build
Post by: S. Heslop on June 08, 2015, 04:45:23 PM
Got the neck blank glued and trued. Took me a while since i'm still recovering from that lung infection.

(http://iforce.co.nz/i/ia4ttxbk.34z.jpg)
Jesus Christ I shouldn't be wearing this shirt on film.

(http://iforce.co.nz/i/g4m3ixk4.psd.jpg)
I'd spent a while fiddling with that thicknesser/ planer to get it cutting a bit better. Tightening up the chain in the depth adjustment thing fixed the wobbly surface it was producing. The two surfaces on the jointer part are both fairly heavily dished, and i'd probably need to scrape them to get them flat. But despite them being crooked and all over the place they seem to cut a reasonably flat surface.

(http://iforce.co.nz/i/54pil4k1.jwn.jpg)
Wish i'd bothered to fiddle with the thing before cutting the boards to glue together though. There's hellacious gaps all over as a result. I'm hoping there's less gaps in the middle, as that'll be on the bottom of the neck. This top surface is gonna be covered by a fingerboard anyways, as well as routed out for a truss rod.


(http://iforce.co.nz/i/eweg4xyh.yls.jpg)
The whole neck skew thing has been confusing me but I think i've figured it out. From what i've read, you want to build the neck like an ordinary neck with the neck center line going through the middle of the peghead at the top. Then you mount it at an angle so that the third string goes through the center line of the banjo. Or something. I figure that means you want to put the truss rod through the neck center line rather than the 'true' centerline (the path of the third string).

I think what makes it hard to understand is that it's hard for people to explain without it sounding like a load of garbage like the above paragraph.

(http://iforce.co.nz/i/tesuey1z.zrk.jpg)
The truss rod doesn't leave alot of material in the top of the neck though. There's about 3.5mm from the corner of the truss rod channel to the edge of the neck. There's also going to be more material removed since i'm going for a tunneled 5th string. I might maybe make the neck a bit chunkier.


I watched a bunch of Czech Pat a Mat cartoons while 'off sick'. They never got broadcast in the UK, which is a shame, because they're really good!
t=49m57s
Title: Re: Banjo Build
Post by: DMIOM on June 08, 2015, 05:28:06 PM
........
I watched a bunch of Czech Pat a Mat cartoons while 'off sick'. They never got broadcast in the UK, which is a shame, because they're really good!
t=49m57s

Oh you so-and-so . :wack:  .... those look great, as if there wasn't enough to watch already!    :beer:
Title: Re: Banjo Build
Post by: S. Heslop on June 08, 2015, 06:30:42 PM
So I got a spokeshave at the boot sale on Sunday. It's a pretty hastily assembled looking thing, which is probably why the seller wanted rid of it despite it looking brand new and boxed. I was thinking about how I might flatten the face the blade rests on (I already had a quick go at it with a file). The obvious way would be to spot and scrape it, but they used an unfortunate choice of paint colour.

(http://iforce.co.nz/i/4lw0xczp.nfd.jpg)
The other problem is sort of visible here, with the closer thread being pitched higher upwards and getting in the way of the blade being held flat. I was gonna ask for advise on what to do, but I think I might make a screw to fit the hole and loctite it in place, then drill and tap that for a thread size smaller, and make a sort of stepped stud to go into it.

Edit: Looking at it further, with the adjusting thumb screws on they prevent the blade from contacting the whole of that face too. Wonder if it's a cock-up with the design in general or if it's only supposed to contact the front of the slot. I also appreciate that the steel of the blade is soft enough that the screw in the frog has put some healthy dents into it.

It's obviously junk but I was hoping I might be able to make something of it.
Title: Re: Banjo Build
Post by: vtsteam on June 08, 2015, 07:15:37 PM
I have a spokeshave bought decades ago that never worked, and I wonder if they are related. I've always since used a drawknife or a plane, or both. I like a drawknife.
Title: Re: Banjo Build
Post by: S. Heslop on June 08, 2015, 07:32:31 PM
Wonder if I could make a draw knife from an old file...

I've got a few old files and I keep trying to think of uses for them. Tried making a scraper from one but I don't think the file steel holds an edge too well when scraping steel or cast iron.

I'm also still considering making some rasps from the old files, perhaps only to spite that video that claimed it takes two years to learn the intricate art of hitting a chisel with a hammer.
Title: Re: Banjo Build
Post by: vtsteam on June 08, 2015, 08:34:34 PM
If the file was tool steel all the way through instead of case hardened, I'm sure you could make a very good drawknife from one. You'd want a good size file, like one of the 14" s I have, and the 5/16" thickness would be good -- better than the 1/4".

You'd need a second tang maybe welded on, or brazed. I guess you could also cut it out of the file, but that would be kind of a waste of good material, and shorten the drawknife. I like a good size one so you clear your hands on the work. A big drawknife can do small work by angling it while cutting. Never needed a smaller one.

The one I've used for 40 years has USN engraved in it -- I'm assuming navy. It's a fantastic tool. I've tried modern woodworking tool company drawknives and there is no comparison. It's shaped just right, perfectly proportioned for the work. Others I've tried are clumsy -- I've tried to teach a few people using those, and when we switch the difference is obvious..

If you get to the point where you want to make one, I can measure this one up and post some photos if you want. Might as well make it shaped well.

I'd love to see you make a rasp, and I bet after two years they do get better, but I bet they also work first time well enough to be happy to have made one!  :thumbup:
Title: Re: Banjo Build
Post by: S. Heslop on June 08, 2015, 09:47:43 PM
I'd very much appreciate some photos. I was looking on google image search and saw all kinds of funny shapes for drawknives and it did confuse me.

Also with skill thing... it's silly but I take that sort of thing personally. A few years ago I took it all serious, and really believed that alot of these things were inaccessible to mere mortals like me. At least not without 2 years of training under a Master Artisan. So it always bothers me when that sort of stuff crops up.
Title: Re: Banjo Build
Post by: vtsteam on June 08, 2015, 10:01:24 PM
Okay, Simon, I'll take some photos tomorrow in good light. Maybe even if I get a chance this next week do a very short video of using it -- they really work well.

Maybe I'll take a photo of the spokeshave I have and never used after the first few tries! It looks very similar to yours!  :beer:
Title: Re: Banjo Build
Post by: S. Heslop on June 09, 2015, 06:59:06 AM
I got the spoke shave working a bit better. Filed the paint off then scraped it a bit. Not a perfect scraping job i've got contact along the front of the blade. I now look like this.

(http://iforce.co.nz/i/30otgxcu.xql.jpg)


I also solved the stud problem by just removing the studs. It's easier to adjust it by tapping the top of the blade with a hammer when its snugged up a bit.
Title: Re: Banjo Build
Post by: vtsteam on June 09, 2015, 08:45:52 AM
 :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:
Title: Re: Banjo Build
Post by: S. Heslop on June 09, 2015, 01:54:01 PM
Trying to anneal the files. Be able to see if it worked in a few hours I suppose.

(http://iforce.co.nz/i/vddpxi2g.zjw.jpg)
Using Rob Wilson's fire bricks and John Mill's burner. Didn't take long for them to glow. In all honesty I almost forgot I had both of these. I rediscovered the fire bricks in the corner of the garage a week ago where i'd stored them so neatly that they were near invisible.

(http://iforce.co.nz/i/mzgchy0y.te5.jpg)
I probably would've been best just blocking the ends of the 'forge' off, but I didn't fancy my chances of the heat soaking through the bricks and doing a number on the patio furniture. So I stuck them in the fire.

Continuing the theme of not thinking ahead I also forgot to get anything to grab the files with. Burned my fingertips through the welding gauntlets.
Title: Re: Banjo Build
Post by: vtsteam on June 09, 2015, 03:20:26 PM
Simon I posted my drawknife pics in "Tools":

http://madmodder.net/index.php/topic,10747.0.html

Title: Re: Banjo Build
Post by: S. Heslop on June 09, 2015, 04:15:49 PM
The files softened. I was able to file them with another file.

(http://iforce.co.nz/i/otjl1qsw.phc.jpg)
Finger for scale, they're pretty tiny teeth. I think a more solid support (there's a table leg underneath this vise but I cut it too short, and it's supported by a wedge that tends to work loose) and a bigger hammer I should be able to get bigger teeth. Not sure how happy this high speed steel will be getting whacked though. Wish I remembered to look for some wee cold chisels at the boot sale.

(http://iforce.co.nz/i/zcfcegjh.mie.jpg)
I sort of assumed you'd want the teeth to lean forwards a bit so they bite the wood, here they're all over the place.

(http://iforce.co.nz/i/1tl3nz1s.c5p.jpg)
Did a little test and it seemed to cut this walnut fairly okay.

I've got two softened files and now i've got to decide which one I want to turn into a curved rasp. I've got some other dull ones I could use too, but the teeth on them are so mighty that it'd take alot of effort to grind them off.

This is all the easy part though. I've gotta find a good place to keep that compressor, then pressure test it to reassure myself that it won't detonate, then start fussing about a sand blasting setup.

The other thing i'm thinking about is how i'd best go about preventing the teeth from burning off when I harden it. I was thinking about perhaps dipping them in plaster of paris, but then that'd probably rust them. Maybe I could try something like cladding them in window putty, which as far as I know is just linseed oil and chalk. Alternately I wonder how well a heavily reducing flame would prevent the teeth from burning.


Edit: I found a photo of some rasp punches, as the guy called them, that i'm putting here mostly so I can find it easier.

(http://iforce.co.nz/i/q5fw5ij3.jan.jpg)
Title: Re: Banjo Build
Post by: vtsteam on June 09, 2015, 04:28:16 PM
Cool Simon!

Well, those are some of the questions I was having, too about old ways of protecting the teeth while hardening. Looks like immersion in a molten table salt bath is the way it's done, now. Linseed oil will burn up. Plaster of Paris might work for the heating phase, but plunging to harden would maybe be too slow with an insulating layer of poP. Lautard in the Machinist Bedside Reader mentions using hand soap rubbed on cutters to prevent scale when heat treating. I've done that and it seemed to work fairly well. Heating the file as much as possible without oxygen would help prevent burning and scale, so burying in hot embers might help as opposed to a burner/blower in air. Maybe a rich torch flame would hep some. Just all maybes, here.
Title: Re: Banjo Build
Post by: S. Heslop on June 10, 2015, 09:21:03 AM
Got the forge set up and ended up using it right away. Picked a helluva day to do it because it's pretty hot.

(http://iforce.co.nz/i/b3ivtwr4.u1a.jpg)
Made a... swaging block I think you'd call it? Ground the bulk material out with an angle grinder and filed the rest to get a good shape.

(http://iforce.co.nz/i/dmgqvyha.kfo.jpg)
It took a while to get the forge working. I kept rearranging the bricks (not a good idea when they're glowing hot!) to get a good shape, and this one seemed to work well for heating the whole thing up at once. It probably also just got better as the bricks got hotter.

(http://iforce.co.nz/i/ctdrrars.i2k.jpg)
The shape looks pretty good in this photo, but from the side it kept curling up. It was also twisting a bit which was spooking me since I had no idea how to try correcting that. As it's finished, i've got the top of it more or less flat I think. Or flat enough to finish up with a grinding. But the bottom of the file, towards the tang, is still a bit curly. I don't think it'll matter too much but it looks a bit silly.

I had problems with the brick barbeque I was doing this on falling apart from the hammer blows. Plus I gave myself a few burns, and singed a bunch of my hair off. And I wasn't too excited about having to heat the entire file up instead of just heating the areas i'm gonna shape. Ideally I probably should've shaped the forge to have a slot the file could pass through, but with the thing hot I couldn't rearrange it so heavily.

I also stuck another big rasp in with the file so hopefully that'll soften too. I was intending to cover it with bar soap to test that idea but I was so busy juggling all the problems I just forgot.
Title: Re: Banjo Build
Post by: S. Heslop on June 10, 2015, 11:29:06 AM
You can see the bendyness here. It also seems to have developed a sideways bend while cooling too.

(http://iforce.co.nz/i/c2xvc0h1.cqj.jpg)

I was thinking about hitting it with a hammer to straighten it out, but I think there's enough of a straight section to be useful. I can just pretend its some sort of exotic rasp for specialist work.

Had a go at smoothing it. I'm having the same problem I had with the helmet, where I can't find a way to remove material fast while grinding. I think it's mostly just the belts i'm using, but i've tried a few brands of belts and not found one that doesn't go blunt very quick. Maybe because they're intended for use with wood.

As a result, there's a bit of a dip inwards at the tip as well as some erosion pitting from the flame that would take alot of effort to grind out. Actually, thinking about it, the steel is soft enough to file...
Title: Re: Banjo Build
Post by: vtsteam on June 10, 2015, 11:53:45 AM
Simon, warping is almost always the result of uneven heating or cooling. One side increases in length from heat while the other possibly more or less plastic does not change at the same rate. When they cool, they are different lengths, and so, curved. So heating all over evenly is pretty much the way to avoid it.
Title: Re: Banjo Build
Post by: S. Heslop on June 10, 2015, 01:19:57 PM
That makes sense.

I've got a new problem now, I can't make a chisel/ punch that will hold an edge. Even went back to the HSS toolblank but it didn't take long for the tip to chip off. I'm wondering is perhaps the file is harder now than it was before.
Title: Re: Banjo Build
Post by: vtsteam on June 10, 2015, 02:31:18 PM
If it cooled rapidly, yes.

Also a lathe toolblank is not designed for impact like a cold chisel is. Start with a re-ground cold chisel and that will work better. You can use silver steel (drill rod) too but you need to harden first and then temper back down to a level that can be used as a metal chisel. Otherwise it will be too brittle.
Title: Re: Banjo Build
Post by: S. Heslop on June 10, 2015, 03:04:18 PM
If it cooled rapidly, yes.

Also a lathe toolblank is not designed for impact like a cold chisel is. Start with a re-ground cold chisel and that will work better. You can use silver steel (drill rod) too but you need to harden first and then temper back down to a level that can be used as a metal chisel. Otherwise it will be too brittle.

I was using some drill rod and just went back to the HSS toolblank after the drill rod didn't work. I'm not really too excited about that drill rod though. I've used it in the past and I felt it was somewhat soft even after hardening. Maybe they sold me the wrong stuff!

One source of pretty good hardenable steel i've found is motor spindles. I think I might still have one hanging around somewhere. I could perhaps use the one out of that drill I wrecked a month or so ago.
Title: Re: Banjo Build
Post by: S. Heslop on June 10, 2015, 04:44:59 PM
(http://iforce.co.nz/i/qbvfoxcf.ka1.jpg)

I made a nice chisel from a motor shaft. Got it hardened (the little gouge on the right was from a good few mighty strokes with a round file, it's maybe not as hard as it could be but it's still pretty hard). And the end got dulled after a couple of taps, and it didn't raise any teeth.

I think i'd conclude from this that the file is still harder than it should be. But if blocking the ends of the firebrick forge wasn't enough to let it cool slowly then i'm not sure what would be. Or rather, i'm not sure what would be practical for me.

I might maybe try running the metal melting furnace and putting the files in that, and blocking it off to let it cool. It's not hugely insulated though, using just dense refractory, and it'd use alot of gas doing that.

One other thing I might be able to try is building a long hearth out of firebrick with a coal or charcoal fire inside, and letting the files cool down inside of that.
Title: Re: Banjo Build
Post by: vtsteam on June 10, 2015, 04:50:42 PM
Put them hot into a bucket of wood ashes. It's perfect insulation for this kind of thing. They'll cool slowly to annealed state.
Title: Re: Banjo Build
Post by: awemawson on June 10, 2015, 04:56:47 PM
Concrete 're-bar' hardens nicely as a chisel in most cases, unless it's Chinese and made from melted down Twin Towers !
Title: Re: Banjo Build
Post by: S. Heslop on June 10, 2015, 04:57:55 PM
I remembered reading about people putting them in buckets of sand, etc. But being fairly thin I imagine they'd lose alot of their heat to the sand as soon as they're put in.

So when you say wood ashes do you mean hot wood ashes? I've got alot of wood scraps that I still need to get rid of. Also should they be glowing before putting them in the wood ashes/ fire or will the wood fire be enough to heat them up?

I did look this stuff up a while ago but I just found a bunch of junk about knife-making. I think 95% of people playing with hot metal are making knives. I'm not sure if i'll ever understand the appeal of knives.
Title: Re: Banjo Build
Post by: S. Heslop on June 10, 2015, 05:02:11 PM
Concrete 're-bar' hardens nicely as a chisel in most cases, unless it's Chinese and made from melted down Twin Towers !

I'm still keeping my eye out for some of the stuff, but despite being apparently ubiquitous i'm having a hard time finding any. I suppose a builders merchants might stock some but they also probably sell them in considerable lengths/ quantities.

I guess any time there's demolition going on of something that'd be full of rebar they'd tend to block the sites off.
Title: Re: Banjo Build
Post by: awemawson on June 10, 2015, 05:02:28 PM
I'm not sure if i'll ever understand the appeal of knives.

Well said that man !
Title: Re: Banjo Build
Post by: awemawson on June 10, 2015, 05:04:27 PM
PM me your address and I'll send you some off cuts
Title: Re: Banjo Build
Post by: S. Heslop on June 10, 2015, 06:46:00 PM
PM me your address and I'll send you some off cuts

That'd be fantastic, thanks.

Did a bit more looking for file stuff and found this video where a guy dunks it into a bucket of vermiculite.



I think I remember Wilkinsons stocking bags of the stuff. I don't really have enough wood ashes to fill a bucket. I'm still not wholly convinced on the idea but I suppose it's worth a go.
Title: Re: Banjo Build
Post by: vtsteam on June 10, 2015, 07:39:14 PM
I remembered reading about people putting them in buckets of sand, etc. But being fairly thin I imagine they'd lose alot of their heat to the sand as soon as they're put in.

So when you say wood ashes do you mean hot wood ashes? I've got alot of wood scraps that I still need to get rid of. Also should they be glowing before putting them in the wood ashes/ fire or will the wood fire be enough to heat them up?

Simon, the wood ashes are just plain (cold) leftovers from any wood fire. They are very light in weight (unlike sand) and highly insulative (unlike sand). We use wood heat here so they are plentiful. I've annealed many times using them, and it is traditional. They are also useful for slow cooling cast iron after brazing or welding to prevent cracking.

Yes you can also use a wood fire for heat to anneal, but you must have a good pile of red hot embers for that (ie. a strong mature fire and strong draft). it is the embers (charcoal actually) that have the high enough temperature. Wood fire flames are relatively cool and won't work. I have used the wood stove to anneal a piece, then plunged it into the ash bucket -- quite handy in winter since they are all normally in one place and indoors.

See my pipe and bolt engine process early on in that Mod-up here on the forum, where I annealed a hard cast iron pipe cap for the crankcase in the wood stove and cooled in wood ashes -- and the result.

Wood ashes can also be mixed with water to make a refractory for lining a forge -- saw that done once on a video, but haven't tried it.
Title: Re: Banjo Build
Post by: vtsteam on June 10, 2015, 07:58:31 PM
Speaking of rebar, I just started laying out the cistern base today. Rebar is availabe at practically any lumberyard here, Home Depots, etc. Cost is currently about $5 per 10 foot length of #4 (1/2" dia.). Bought 30 lengths yesteday.

Never tried hardening it for tools....

(http://i786.photobucket.com/albums/yy150/vtsr/vtsr/Shop/Cistern1.jpg)
Title: Re: Banjo Build
Post by: awemawson on June 11, 2015, 04:21:58 AM
Simon,

A couple of bars are all wrapped up and being collected by MyHermes on Friday - should be enough to make four chisels
Title: Re: Banjo Build
Post by: S. Heslop on June 12, 2015, 08:34:47 AM
Take two.

(http://iforce.co.nz/i/epfulk2m.jpa.jpg)
Reshaped forge worked quite well. Perhaps could've been a bit longer where I stick the metal in, to cover more of the file. And ideally i'd have blocked more of the end where the burner goes since it was fairly open and had a bit of a flame coming out of it as well.

(http://iforce.co.nz/i/zzfodbdp.ryz.jpg)
The vermiculite i'm not so excited about though. Gotta let it cool, but there's a fair amount of steam coming off of it, which i'd sort of expected after reading the packet and it saying something along the lines of 'ideal for absorbing water'. The bin also sprung a leak out the side where the heat from the file made it about.. 5cm? It's a short distance but it happened fairly fast.

So i'd be surprised if it works. Plan C will be to build a sort of tall furnace from either sheet metal or something like a bit of pipe (ducting perhaps?). Then make a plaster of paris/ vermiculite lining, fill it with charcoal, send air in via a vacuum cleaner, and let the files heat up and cool down inside of that.

I'm also considering giving this up and just buying some rasps. I sort of want to save the sheet metal for another stupid idea I had.
Title: Re: Banjo Build
Post by: vtsteam on June 12, 2015, 08:53:03 AM
Simon, for holding ashes, think metal bucket, as in galvanized pail, or garbage pail or large gallon (or metric equivalent) size commercial tomato tin. Or gallon paint can (though these are increasingly being made in plastic here). 5 gallon roofing compound tin. Propane tank. Anything discarded that's metal and round. Fire extinguisher......yes?

Vermiculite will work, not as well as wood ashes, but must be completely dry -- otherwise you're making steam, which process rapidly absorbs heat.

There is nothing wrong with your bricks for a furnace -- or forge, you don't need metal lined with plaster of Paris (unless you want to do that as a project). You could also mortar your bricks together with plaster of Paris and sand, using relatively little plaster and make a more permanent forge or furnace.
Title: Re: Banjo Build
Post by: S. Heslop on June 12, 2015, 09:02:09 AM
I was thinking about welding a couple of galvanized buckets together. Mostly I need the height.

Drying and keeping the wood ash/ vermiculite dry is a problem though. And with my current space constraints i'm half expecting to throw the stuff out once i'm done with it.

The idea with the charcoal forge/ furnace is just to let the files cool down slowly as the fire itself dies out. Whatever I build might not even need to be lined with refractory, i'm just trying to think of uses for the vermiculite. If I build something nice I could disguise it as a garden ornament. Some sort of tall square tapered thing with some planters on top.
Title: Re: Banjo Build
Post by: vtsteam on June 12, 2015, 09:10:15 AM
Well, do you have over there a 10 gallon (metric equiv) galvanized steel dustbin with lid? That is tall, can be kept outdoors and will keep anything inside dry.
Title: Re: Banjo Build
Post by: awemawson on June 12, 2015, 09:31:52 AM
6" clay or iron drainage pipe would work, but why can you not just let them cool in your forge - I doubt it'll cool fast enough not to leave them soft ?
Title: Re: Banjo Build
Post by: S. Heslop on June 12, 2015, 10:13:40 AM
6" clay or iron drainage pipe would work, but why can you not just let them cool in your forge - I doubt it'll cool fast enough not to leave them soft ?

Yeah it surprised me when it didn't work because that's what I tried the second (I think?) time.

Also I think the problem with moisture isn't things getting literally wet, but them absorbing water vapour. The vermiculite was dry to the touch but still gave out a surprising amount of steam.

Also also I took one of the files out the bin and touched the tip of it into some water, and it seems to still be above at least 100C after an hour. So it's at least cooling faster than in air.
Title: Re: Banjo Build
Post by: vtsteam on June 12, 2015, 11:28:41 AM
Quote
For most tool and high speed steels, the annealing temperature is about 1600 degrees F (870 C). The tool will need to be held at that temperature for hours. A good rule of thumb is one hour per inch of thickness with a minimum of 2 hours.

The second stage of the annealing process is a slow cooling process. After the tool has been heated and held at the proper temperature, it needs to be cooled at a very slow rate. Generally this rate is 50-100 degrees F (28-56 C) per hour. This is usually performed by leaving the tool in the furnace, turning off the heat and keeping the door closed. The tool can be cooled in still air after the temperature of the tool falls below 1000 degrees F (540 C). After the tool has reached room temperature, it is soft and able to be machined.

I imagine they're talking about a considerably larger furnace and a sealed one at that, to get that slow a cooling rate.

For me it was easy to just put the part in the wood stove embers and leave it -- I don't think I had it in a full hour, but it wasn't just heating for a few minutes with a torch either. Then bury it in a bucket of wood ashes, which I'm sure cooled very slowly, and were dry.

One nice thing about a solid fuel fire is it will die out slowly, so that's another possibility -- put it in coals, or wood embers, keep it hot for awhile, and then let the fire die out naturally around it,. It will likely be covered in ash as well. Seems like a natural for the barbecue, if you have one.
Title: Re: Banjo Build
Post by: vtsteam on June 12, 2015, 11:55:35 AM
A lot of good info on annealing high carbon and alloy tool steels here:

http://www.anvilfire.com/article.php?bodyName=/FAQs/heattreating.htm

looks like it might have to be VERY slow cooling, depending on what alloy you happen to have.

The one surprising point in your case Simon is that you seemed to succeed in making the blank soft the first time since you were making rasp marks in it easily. So the question is why, and what changed? Diffrent blank?
Title: Re: Banjo Build
Post by: S. Heslop on June 12, 2015, 11:56:27 AM
Yeah the vermiculite didn't work. We do have a barbecue but it's fairly shallow. But I did notice that my grandad has acquired a real giant charcoal bbq, the half a drum type. 

I also noticed that the files just barely fit into the metal melting furnace, with the tips of the tangs poking out through the hole in the top. Perhaps I could do something with that. I think I remember reading that a tangential inlet doesn't work so great with charcoal but perhaps a strategically placed bit of firebrick might help direct the blast.
Title: Re: Banjo Build
Post by: S. Heslop on June 12, 2015, 12:02:05 PM
A lot of good info on annealing high carbon and alloy tool steels here:

http://www.anvilfire.com/article.php?bodyName=/FAQs/heattreating.htm

looks like it might have to be VERY slow cooling, depending on what alloy you happen to have.

The one surprising point in your case Simon is that you seemed to succeed in making the blank soft the first time since you were making rasp marks in it easily. So the question is why, and what changed? Diffrent blank?

The first time I heated it up red, then stuck it into the embers of a dying wood fire. Half the file was still poking out though since the fire wasn't big enough.

Plus I was using high speed steel to punch those marks, so that might've helped. The stuff i've been trying to make punches from does harden, but it can still be (just barely) filed. So it's not as hard as it should be. I also tried grinding a bit into that steel to make sure I wasn't just filing off a decarburized layer. Hopefully Andrew's bits of rebar will work better when they arrive.

Y'know it'd probably be diligent to try the high speed steel again. I had the tip snap off (which is to be expected) trying to punch it after the first hardening-steel chisel didn't work, and I never tried it again.
Title: Re: Banjo Build
Post by: S. Heslop on June 12, 2015, 12:29:59 PM
Tried the HSS again. Got about 4 teeth into it before the tip broke off. Perhaps it is just the steel I was trying to harden for the punches. I guess i'll find out when that rebar arrives!
Title: Re: Banjo Build
Post by: vtsteam on June 12, 2015, 01:40:12 PM
I still think a cold chisel is the way to go, don't you have one kicking around in the rust and odd bolts, shot VW Beetle condensers, and half bent cotter pins at the bottom of your tool box? Everybody else does.  :lol:
Title: Re: Banjo Build
Post by: vtsteam on June 12, 2015, 08:09:24 PM
This one was kinda interesting:

Quote
To anneal a small piece of tool steel you may need to bury it with a larger piece of steel heated much hotter (an orange). Bury the two pieces next to each other but not quite touching. Test as above. Remember, the 40F (22C) per hour is a maximum rate, the slower the anneal the softer the steel (to a point).
Title: Re: Banjo Build
Post by: chipenter on June 13, 2015, 02:57:20 AM
Have you tried another file as a chisel just let the colors down to dark straw , no need the anneel and reharden .
Title: Re: Banjo Build
Post by: S. Heslop on June 13, 2015, 12:09:09 PM
Have you tried another file as a chisel just let the colors down to dark straw , no need the anneel and reharden .

I feel that files are too thin.

I remembered that I have a whole bunch of empty fire extinguishers that'd probably make good holders for the charcoal. Not sure how important insulation is though. I imagine I'll be getting the files hot outside of the fire first.
Title: Re: Banjo Build
Post by: S. Heslop on June 14, 2015, 12:42:41 PM
Take three.

(http://iforce.co.nz/i/n2moxql1.t4y.jpg)
It got pretty hot inside. I'm a little worried the files might've melted.

(http://iforce.co.nz/i/yjtjjdfb.av4.jpg)
Kept topping it up with charcoal. This big rasp is too tall for this really, i'm worried that the exposed end might conduct the heat out too fast. I had the whole thing glowing but after switching it off I compacted the charcoal down a bit and the end was already cool.

Anyways, it won't be till tomorrow till I can see how it worked. It at least seems to be cooling slower than with the other methods.
Title: Re: Banjo Build
Post by: S. Heslop on June 14, 2015, 04:47:37 PM
Decided to pull the big rasp out, and the others came out with it. They've melted and fused together!

Might be the end of the rasp adventure. I suppose i'll see how well they softened tomorrow.
Title: Re: Banjo Build
Post by: vtsteam on June 14, 2015, 05:11:20 PM
Gee, I spend half a summer trying to build a charcoal burning iron melting sawed of cupola, which doesn't work, and you just stuff some charcoal in an old fire extinguisher and melt alloy steel with it!  :doh:

 :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:


No refractory or nuttin....!
Title: Re: Banjo Build
Post by: S. Heslop on June 14, 2015, 06:21:29 PM
Gee, I spend half a summer trying to build a charcoal burning iron melting sawed of cupola, which doesn't work, and you just stuff some charcoal in an old fire extinguisher and melt alloy steel with it!  :doh:

 :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:


No refractory or nuttin....!

I figure it won't last long till the thing burns through though. I'm interested to see how eroded the inside is after dumping the ashes out (into another fire extinguisher. Might as well hold onto them).
Title: Re: Banjo Build
Post by: vtsteam on June 14, 2015, 07:15:55 PM
Simon, I think natural draft might have worked better.
Title: Re: Banjo Build
Post by: vtsteam on June 14, 2015, 07:24:59 PM
Check the image in this post, it's from Andrew Weyger's Blacksmithing books. It shows a natural draft forge made from a can and stovepipe. I don't personally think that much stovepipe is necessary -- probably a couple feet would do. In fact another fire extinguisher, maybe.

http://www.iforgeiron.com/topic/29696-my-better-bellow/?do=findComment&comment=304844
Title: Re: Banjo Build
Post by: awemawson on June 15, 2015, 02:48:36 AM
That illustration of the hanging forge looks like an excellent way to set fire to a tree  :bugeye:
Title: Re: Banjo Build
Post by: S. Heslop on June 15, 2015, 05:05:30 AM
Simon, I think natural draft might have worked better.

I think having a more controllable blower would've helped. I had the outlet of a vacuum cleaner and tried a few crude ways of adjusting the air but none of them worked. Plus I started to get concerned about the top layer of charcoal not igniting, and so I was going full blast to try get the air to reach the top as well.

I did also think about removing the files and then putting them back in when it got hot, but to get the files in they had to be hammered down, which I wasn't so excited about doing over the hot coals.
Title: Re: Banjo Build
Post by: vtsteam on June 15, 2015, 08:39:34 AM
Simon if you happen to need to control a blast in a simple fashion without a normal diverter, you can just have short pipe on the blower separated from a longer pipe in the tuyere. You just alter the distance between the two, and the aim between them until your furnace is running at the rate you want. A few bricks can hold the pipes in position.

Andrew, I'm sure Mr. Weygers was careful not to burn down his tree. The devil is in the details, as in most things having to do with fire, Including bonfires, campfires, etc. His books are blacksmithing classics, and I admire them greatly.

I can hold my hand two feet above the 2' length of stovepipe I set on my current melting furnace comfortably, and that is while melting metal with a blower, not just forging small parts in a tin can forge with an atmospheric draft.

A longer pipe suspended well below a limb on a small atmospheric forge as shown will run quite cool. Most anything we do can be dangerous if approached without awareness. Running a blown exhaust direct into pine needles during a drought wouldn't be advisable, but I think most people wouldn't do that. I wouldn't even run my iron furnace in the clear under drought conditions. Even running a hand grinder can be danerous then. An illustration of what the author found useful does not absolve people from using good sense when doing the same.
Title: Re: Banjo Build
Post by: S. Heslop on June 15, 2015, 09:14:55 AM
Simon if you happen to need to control a blast in a simple fashion without a normal diverter, you can just have short pipe on the blower separated from a longer pipe in the tuyere. You just alter the distance between the two, and the aim between them until your furnace is running at the rate you want. A few bricks can hold the pipes in position.

I was actually trying something similar to that, by angling the vacuum cleaner nozzle on the end of the pipe going into the extinguisher. Sort of balancing it at an angle so it wasn't throwing all the air in. But like I said I decided to go for full blast to try get the charcoal on top burning.

But yeah I think i'm done with this rasp stuff now. I'd have to find some more old files to continue it for starters.
Title: Re: Banjo Build
Post by: awemawson on June 15, 2015, 09:36:47 AM

Andrew, I'm sure Mr. Weygers was careful not to burn down his tree. The devil is in the details, as in most things having to do with fire, Including bonfires, campfires, etc. His books are blacksmithing classics, and I admire them greatly.



Steve,

A previous owner of our place, when doing some building works, decided to burn rubbish too close to the base of a rather nice (at least 200) year old Yew tree. So looking from the field towards the house you saw a lovely tree, but from the house side all the branches were scarred, black,  and dead. It did at least salve my conscience when it had to come down to make way for an extension.

Ironically he is a retired member of the London Fire Brigade  :lol:
Title: Re: Banjo Build
Post by: vtsteam on June 15, 2015, 10:00:37 AM
Andrew my former neighbor was head of the fire department here. He and  the department were burning some grass off of his field opposite as practice and it got out of control. Managed to get it out just before it jumped the road to my property!

It's kinda like how most psychiatrists are in their personal lives nutcases....  :lol:
Title: Re: Banjo Build
Post by: S. Heslop on June 15, 2015, 03:43:14 PM
Hey that rebar arrived today. Thanks again for sending it.

Just a shame that I don't really need it for the rasps any more. Either way i'll find a use for it eventually.
Title: Re: Banjo Build
Post by: awemawson on June 15, 2015, 04:11:27 PM
Glad it arrived safely
Title: Re: Banjo Build
Post by: S. Heslop on June 15, 2015, 04:56:34 PM
So am I! I thought it'd be a much narrower diameter.

Just remembered I'd forgotten to post pics of the aftermath.
(http://iforce.co.nz/i/vdurcm21.ug4.jpg)

Reduced to slag. The big rasp is still somewhat intact and I was hoping i'd be able to easily separate the files since along alot of the length it didn't fuse. But where that big lump of slag is they're well and truly fused. I'd have to get some more disks for the angle grinder to get it apart.

I think before i'll call it entirely quits, i'm gonna see if I can save that large rasp. I was looking at buying rasps and found that those French clowns from the video sell them for over 100 each, along with woodwork blog eejits saying 'quality tools that'll last you a lifetime and well worth the investment!', and that renewed my interest in trying to make one. I'm taking this rasp business very personally.
Title: Re: Banjo Build
Post by: Bluechip on June 15, 2015, 05:17:10 PM
Being a dumb old fart, why all this fuss about rasps ?? Have I missed something ??

In my younger days, if I wanted to inflict hideous injury on some innocent bit of timber my weapon of choice would be a Stanley Surform in one of it's variants.

In my youth I had to use a thing called a 'Dreadnought' file on copper bus-bars and they were murderous damn things. Needed about 400HP to shift the abominations. Purple in the face,  going weak at the knees and hardly a copper shaving to be seen ...  :bang:

Off to me chariot, Sanatogen time ...  :palm:

Dave
Title: Re: Banjo Build
Post by: S. Heslop on June 15, 2015, 05:26:50 PM
I've got one of those dreadnought files, but it's beyond dull. I keep thinking that the teeth are so huge that I could probably revive it by grinding the tops with a rotary tool. But with the size and shape of the teeth i'm not convinced it'd be useful for much.

I've also seen those surforms all over. I almost bought one a couple of weeks back, in fact. Couldn't find any large round/ half round ones though so I figured a rasp would be ideal for inside radii. I suppose maybe I could bend them into a half-round...

But most of the rasp fuss is just because it's something that I feel should be possible to accomplish, and so I want to do exactly that. I guess there's a little bit of interest in finding uses for old files as well. Maybe save a few from the terrible fate of becoming dorky knives.
Title: Re: Banjo Build
Post by: Lew_Merrick_PE on June 15, 2015, 07:18:43 PM
My tuyere feed is made up of (4) 120 cfm 12VDC fans with an adjustable voltage regulator (built up from LM317 adjustable regulators) that allow me to feather the airfeed.  At full speed, I can get quite a "fire" -- and adjust it down to the merest of a "breath" feed.
Title: Re: Banjo Build
Post by: vtsteam on June 15, 2015, 09:17:33 PM
Well I gotta say I like rasps (though I don't own any expensive ones) and have had poor luck with sureforms. In fact only bought one, once, and wasn't too happy about that after. There's a big difference to me between a flexible piece of sheet metal like a cheese grater and a solid steel rasp. I guess sureforms must work maybe for rough work in softwood, but I'll take a simple 4-in-hand rasp and rat tail rasp for preference for most work I'd want to do, Of course more shapes is better, but those are the minimum for me. I'd be hard pressed without a low angle block plane, and chisels too.
Title: Re: Banjo Build
Post by: awemawson on June 16, 2015, 04:35:31 AM
I gave up with Surforms - they'd be fine for the first ten minutes then rapidly declined in sharpness - I think that the formed teeth tend to bend back and put their heads under the parapet!
Title: Re: Banjo Build
Post by: S. Heslop on June 16, 2015, 06:02:06 AM
4-in-hand rasp

Oh that's what they're called. It's also interesting to hear that about surforms. I was never too confident in them just from the way they looked. If I remember right they come in a few different teeth shapes, some have sort of arched teeth from being punched down, and others have a fair amount of material removed around the tooth which is then bent down but kept rather straight. The second variety (neat story) in particular never seemed so ideal.
Title: Re: Banjo Build
Post by: S. Heslop on June 16, 2015, 11:50:51 AM
So that big four in hand rasp seems to have gone soft. Or perhaps it was only ever case hardened. I'll probably cut a tang into it and then try hardening the waste to test.

Also I've been wondering about case hardening. Perhaps I could put teeth into a bit of mild steel then try case hardening that. If you're using fancy materials like kasenit (which seems to be sodium ferrocyanide, which I still haven't found a source for but i'm sure it must be available. Perhaps I could contact a chemicals distributor. Or maybe even ask my old university chemistry department) would it be enough to protect the teeth from burning away? The thing of sealing it in a tin with charcoal seems fussy, mostly for the risk of burning a hole in the tin.

I'm also considering skipping the sandblaster part, and going for an acid etch. I think i've read that they used to do them that way before the days of sandblasting.


Finally, i'm also even wondering if the teeth need to be hardened. I'm sure it'd help, but it might be worth seeing how long they'd last if left soft.
Title: Re: Banjo Build
Post by: vtsteam on June 16, 2015, 12:10:49 PM
questions, questions! Only way to find out some of these kinds of things is to try them! :dremel:

Kasenit does seal to the part being heated so doesn't need a container, and also acts rapidly, but to mainly produce a thin case.

The pack hardening methods are usually used to get a thicker case. The container wouldn't likely be a tin, but something thicker -- pipe is sometimes mentioned -- one end pipe capped, the other just plugged with clay (likely the obvious explosive safety reason). Or a custom made box and lid, also luted with clay.

Kasenit seems to be more than (or other than) sodium ferrocyanide, since it is gray in color.

I've read statements that wood actually can wear tools faster than metal -- source lost to memory, so take with a grain of salt. But best to find out by trying, yourself, I always feel.

I bet the scraps from your 4-in-hand rasp harden when you try them.

ps, can you make a rasp from Andrew's rebar and then harden?

I'm going to still plug for forging whatever metal to shape and immediately burying in genuine wood ashes for a few hours, by way of annealing.
Title: Re: Banjo Build
Post by: awemawson on June 16, 2015, 12:18:57 PM
The original Kasenit used to fuse into a smoothish layer when a red hot item was dipped. The modern stuff seems to have major problems adhering  :scratch:
Title: Re: Banjo Build
Post by: S. Heslop on June 16, 2015, 01:45:35 PM
I've also heard about wood wearing tools faster. I think i've also heard that bits of sand and grit can get embedded in the wood as it grows, more so in some varieties.

I'm not convinced it does wear tools faster though. Think about a chisel or a plane iron, which are usually just high carbon steel.

Also I did think about making a rasp from the rebar, but I don't think I particularly need a round rasp at this time.


So it seems that making case hardening compound is just gonna be another distraction, and a potentially dangerous one too. Is there any particular go-to variety of case hardening compound? I often hear people complain that the new safer stuff isn't anywhere near as good as the old stuff but I don't think I often hear recommendations.
Title: Re: Banjo Build
Post by: awemawson on June 16, 2015, 02:15:03 PM
The modern stuff works, but you need to keep heating and plunging as it comes off too easily imho.
Title: Re: Banjo Build
Post by: S. Heslop on June 16, 2015, 03:53:03 PM
Sounds like it'd be tricky to do without burning the teeth off.
Title: Re: Banjo Build
Post by: S. Heslop on June 16, 2015, 04:36:51 PM
I'm now wondering about getting some pipe just wide enough to hold the largest file, then welding the end off and filling it with salt, and putting it in that charcoal furnace. Maybe making a ring to support it from tipping over.

Molten salt seems like something that I shouldn't be playing with. Molten metal should at least slide off of skin and clothes, but i'd imagine molten salt would stick to everything. But it's still something i'm considering.

Edit: Yeah forget that. It's too dangerous and i'd be an idiot to try it.

Edit2: I think case hardening seems like something interesting to try. I'm reading more into it. I'll probably do it the traditional way with a sealed(ish) container. I'm just thinking now about how to monitor the temperature so I don't melt anything again. If I can get it to work then it seems like it'd be a reliable way to make rasps from fairly common materials.
Title: Re: Banjo Build
Post by: S. Heslop on June 17, 2015, 05:48:43 AM
So I'm reading that people but bone meal/ bone charcoal in mostly to give it a 'colour case harden'. Almost all the stuff i've found on case hardening has been people trying to turn nice looking guns into marbly messes like this.

(http://iforce.co.nz/i/owf4hnyo.uqx.jpg)

I can only figure it became synonymous with 'quality' due to it being at least visually obvious that the thing has been case hardened. Cuz it sure as hell looks ugly.
Title: Re: Banjo Build
Post by: vtsteam on June 17, 2015, 09:24:39 AM
Simon  :lol: now don't go messin with gun folks aesthetics. They got their own styles, just like we do -- some like everything in the machine shop gray, some like things green, some go for red, blue, orange, and there's even a guy I know who painted his thickness sander purple! I say go for it, when you build yer own stuff, whatever takes yer fancy. I kinda like the marbeling from hardening -- it's interesting and a bit uncontrolled, which is rare in factory made plastic everything these days! :beer:
Title: Re: Banjo Build
Post by: S. Heslop on June 17, 2015, 11:55:55 AM
I understand that people appreciate some weird stuff, but what gets my goat is when certain things become associated with quality. I'm sure you've probably seen some of the horrific bluegrass banjos out there.

In other news, I tried hardening the leftover tang of that rasp and it did indeed harden. I've got the other half of the tang that I might try coating with bar soap to see if it at all protects teeth as it's heated.

I also remembered i've got a big bunch of 50x50x5mm angle iron that would probably make a good canister for case hardening if I weld two halves into a square tube. It'll also be nice to weld something with some thickness for a change. It seems like everything I weld is either tiny or very thin. 
Title: Re: Banjo Build
Post by: S. Heslop on June 17, 2015, 12:52:05 PM
(http://iforce.co.nz/i/zxbvs3bv.t3m.jpg)

Tried it with a bit of soap and a gas flame and it seemed to do something. It didn't harden as well as the previous bit though, since I didn't let it 'soak' I suppose. Wish I thought to take before and after photos, but it didn't seem to degrade too bad. The two leftmost teeth are snubbed off because I brushed them with another file seeing how hard they got (not very). I also didn't do a great job forming the teeth either.

Trying to get that rebar to harden. Spent a good while whittling that into a chisel shape, roughing with a hacksaw. But it's too chunky to easily heat and I think I jumped then gun on quenching it; hadn't gotten it hot enough.
Title: Re: Banjo Build
Post by: awemawson on June 17, 2015, 01:15:01 PM
Some nice old rasps in this thread on the welding forum - reckon a bit of negotiation might liberate some for you:

http://www.mig-welding.co.uk/forum/threads/worth-80quid.55640/
Title: Re: Banjo Build
Post by: Lew_Merrick_PE on June 17, 2015, 01:15:52 PM
Simon,

>> I think I jumped then gun on quenching it; hadn't gotten it hot enough.

Try using a magnet on a wire.  [I use .004 inch music wire because I use that in a number of other operations.]  A good AlNiCo magnet should draw towards the heating part enough to see while staying far enough away from the heat source.  [Do not try this with neodymium magnets as they do strange things when they get "warm."]  When the steel no longer attracts the magnet, you are (approximately) at the correct temperature for hardening.
Title: Re: Banjo Build
Post by: S. Heslop on June 17, 2015, 01:47:34 PM
I did have a magnet I was using, but it fell into the garden somewhere when trying to anneal the rasps and i'll probably never see it again. Got a few old speakers from a TV i'll probably never use, so I might try borrowing a magnet from those.
Title: Re: Banjo Build
Post by: vtsteam on June 17, 2015, 02:06:24 PM
I did have a magnet I was using, but it fell into the garden somewhere when trying to anneal the rasps and i'll probably never see it again. Got a few old speakers from a TV i'll probably never use, so I might try borrowing a magnet from those.

Well that's the opposite of what usually happens to me -- I drag a magnet around to find a lost steel part in the grass! Can you drag a piece of your angle iron around to find your magnet?
Title: Re: Banjo Build
Post by: S. Heslop on June 17, 2015, 03:36:34 PM
I did have a magnet I was using, but it fell into the garden somewhere when trying to anneal the rasps and i'll probably never see it again. Got a few old speakers from a TV i'll probably never use, so I might try borrowing a magnet from those.

Well that's the opposite of what usually happens to me -- I drag a magnet around to find a lost steel part in the grass! Can you drag a piece of your angle iron around to find your magnet?

I'd need to be probing the bushes because I think it went down the side of the barbecue. I knocked the screwdriver off that the magnet was stuck to, and it fell off of that.

So I still can't get this rebar to harden. Andrew, what do you usually do to harden it? I've been getting it progressively hotter (and past the magnetic point) and quenching in water.

Also I did pick up a cold chisel at a second hand shop. I was thinking about grinding it into a shape for this but it's a bit too long, and it seems like a shame to ruin it. So I ended up grinding it into a shape for cutting metal and honed it to a nice edge. Played around for a bit cutting metal with the thing and it's holding it's edge great, even on steel. I've heard that alot of fitting in the past used to be done with files and chisels, but i've never really understood the purpose of chisels since they more or less do what files do. I suppose they can remove material much faster to rough it out?
Title: Re: Banjo Build
Post by: awemawson on June 17, 2015, 04:04:59 PM
Simon remember that rebar does vary in composition so it is possible that may not harden at all, but it should. Heat somewhat above the curie point then rapid quench in cold water. That will make is as hard as it can be.
Title: Re: Banjo Build
Post by: S. Heslop on June 17, 2015, 04:51:36 PM
It is hardening I suppose, just not hard enough to survive it's purpose. I might try case hardening it too to see how that goes.

Either way, it's a good pair of bars that i'll eventually find a use for. I've been running low on long bits of steel bar.


Speaking of bars, I was spending a while wondering about how I might monitor the temperature while case hardening, to make sure I don't melt through the canister. I was thinking about the expensive and complicated ways, naturally, using thermocouples. Then I realised that I could probably just stick a bit of rod down in the fire and pull it out occasionally to see how hot it is from the glow.
Title: Re: Banjo Build
Post by: vtsteam on June 17, 2015, 09:11:28 PM
Also I did pick up a cold chisel at a second hand shop. I was thinking about grinding it into a shape for this but it's a bit too long, and it seems like a shame to ruin it. So I ended up grinding it into a shape for cutting metal and honed it to a nice edge. Played around for a bit cutting metal with the thing and it's holding it's edge great, even on steel. I've heard that alot of fitting in the past used to be done with files and chisels, but i've never really understood the purpose of chisels since they more or less do what files do. I suppose they can remove material much faster to rough it out?

Yes, they can shear sheet metal held in a vise with a guide, chip grooves, rough down a surface, clean up castings, free steel cores in castings (like my half-nut on the lathe), get in corners you can't get a mill into, cut square where a mill might only be able to do round, split frozen nuts off of bolts and studs, cut off rivets and bolt heads, act as an impact wrench on really big nuts, mark part orientations, etc.

This is a really light treatment, but the best i could find for the moment on the inet:

http://www.appropedia.org/Cold_chisels
Title: Re: Banjo Build
Post by: vtsteam on June 17, 2015, 10:06:45 PM
And found a video, there isn't much out there on cold chisels. Older books and MEs have more  information. I have quite a few cold chisels. Some of the narrower ones are the handiest. It's kinda like hammers. Hard to resist them on a garage sale table, for me at least.

Title: Re: Banjo Build
Post by: S. Heslop on June 18, 2015, 04:18:14 AM
Yeah it surprised me that there's next to nothing on cold chisels on the internet. I feel like any time you see old film footage of a factory you're gonna see more than a few guys using them. Then with the woodworking hand tool scene you'd think there'd be an equivalent for metalwork.
Title: Re: Banjo Build
Post by: DavidA on June 18, 2015, 06:30:23 AM
Re the Poor Man's Milling Machine.

As part of my army training I had to do a plant operator/Mechanic course. This was back in 1969.

As part of that training we did metal work. and during this we had to cut a channel in a steel block to quite close limits using only a hammer, cold chisel,  hack saw and files.
I was swinging mightily with the hammer when someone distracted me and I missed the chisel; But not my hand.
The pain was so intense I nearly fainted (Note,  nearly. Royal Engineers don't faint) . To this day the knuckles on my left index finger are slightly deformed and, particularly in winter, it hurts like hell.

An experience to be avoided where possible.

Dave.
Title: Re: Banjo Build
Post by: vtsteam on June 18, 2015, 09:22:16 AM
It's pretty common to hit your hand, probably because we all tend to use too small a hammer. All too often people grab a household claw hammer to hit a cold chisel with (me included). After enough whacks I've come to instinctively pick a bigger hammer -- the larger the face the less chance you'll miss, and the additional weight is more effective.

You can slow down the hit as well with a heavier hammer, hit less frequenty, which makes it also a lot more accurate in cut. Fast pounding with too light a hammer gets you nowhere, except bleeding. Tapping with a heavier one gives time to adjust hammer aim and tool angle, yet takes off a good chunk of metal with every blow. Of course the hammer size has to be guaged to the size of the chisel.

I don't think a long handle on a hammer helps, and I notice others tend to choke up on the handle where it is  framer length.

If you think about wood chisel practice, there's usually a round mallet or maul with very short handle and good weight, and large hitting area, and you seldom miss, while maintaining good accuracy. I think that also applies to cold chisels, and improvements could be made in what we hit them with.

Some of the usual problems crop up this well meaning video:

Title: Re: Banjo Build
Post by: S. Heslop on June 18, 2015, 10:50:22 AM
I hit my own left index finger knuckle with a big hammer a couple of weeks ago. Right where i'd also hit it with a wood chisel. It's still somewhat sore if I prod it. Seems like that area is the most likely to get hit by stuff! In fact I kept hitting it with that chisel and reopened the cut a few more times till I got the hint. I wonder if those plastic rings you can get for cold chisels to help protect from missed blows are worth it... I could perhaps make something similar from plywood.

Worked on that canister today.

(http://iforce.co.nz/i/v1brk3mt.lrk.jpg)
It doesn't look like much but I put a good amount of work into this end cap. I got it fitting just right. Played with the cold chisel a bit more, and i'm not sure if it's just my technique but I felt I could remove material much faster with the half round part of a coarse crosscut file.

(http://iforce.co.nz/i/yuyagp3r.s5x.jpg)
Welded. I miss my welding cap and helmet. I lent it to my brother a long time ago and never saw them again, he left them at his old workplace. This handheld visor is pretty rubbish and plenty of spatter landed on top of my head.

Earlier I welded the long seams without the jacket on, just a T-shirt with my arms exposed. I kind of realised what i'd done afterwards but so far i've got no symptoms of arc burn.

(http://iforce.co.nz/i/hckqdhua.jfx.jpg)
The ugliest weld. I went over the lousy first pass at about 120 amps (according to the buzz box) hoping to get some better penetration, but there's still nothing visible on the entire inside of the canister.

(http://iforce.co.nz/i/1ibj2qbj.zgt.jpg)
The end was equally ugly. I went a bit fast in a few parts (the handheld visor has a very dark shade in it, it's hard to see what's going on even with the arc light) and touched them up.

Time really flied doing all of this. Started at about 10am and it's now almost 4pm. Hopefully i'll have the lid finished by the end of the day. I'm still thinking about what to do, but I think i'll just make two squares and do some plug welds to hold them together, with the inner square (fairly loosely) fitting the inside and the larger square overhanging a bit so I have a corner to shove fireclay into to seal it.

I had a dream last night I was trying to weld in the back of a car. I had nowhere to set the hot metal down so I flung it out the window and started a wildfire. Hopefully it wasn't a premonition!
Title: Re: Banjo Build
Post by: awemawson on June 18, 2015, 11:09:47 AM
Modern cold chisels tend to come with those rubber safety discs round the head, but I must confess to finding them more of a hindrance to visibility than a help and remove them. Anything not too delicate I use a club hammer with a cold chisel so the face is about 2" square, and a normal ball peen for smaller stuff.

Cold chisels are excellent for removing weld splatter
Title: Re: Banjo Build
Post by: DMIOM on June 18, 2015, 12:26:05 PM
.......Cold chisels are excellent for removing weld splatter

even here?

...... plenty of spatter landed on top of my head.......

 :hammer:
Title: Re: Banjo Build
Post by: S. Heslop on June 18, 2015, 01:13:58 PM
(http://iforce.co.nz/i/xwhwoxt3.oyn.jpg)
I always wonder if there's some sort of solution for gripping awkward parts in a vise like this. If I had more space i'd consider making a vise pedestal, filled with concrete and anchored to the floor, to give more space below the vise where the jaws overhang.

I also solved the head spatter problem by putting the face shield on, with it lifted up to cover my head.

(http://iforce.co.nz/i/njtf3jl0.ooa.jpg)
Job done. I might punch the slag out of those holes just in case it interferes with the case hardening. I'm also considering putting a sort of trim around the edge, to give a better space to fill with the fire clay.

It's kinda silly how proud I feel about this ugly welded tube.
Title: Re: Banjo Build
Post by: vtsteam on June 18, 2015, 02:14:08 PM
I'd be proud of that myself.  :thumbup: :clap:
Title: Re: Banjo Build
Post by: S. Heslop on June 18, 2015, 03:32:55 PM
I thought i'd do a quick bit in the garage, cutting a slice of steel to curl up tomorrow to try making a half round rasp again. Decided to break out the circular saw and cut over a foot in a few seconds. Makes all that effort with the hacksaw seem pointless!

I think i've already said it, but i'm really impressed with that saw. Got it from Aldi on a whim, and the box said not to cut (I think) more than 3mm of steel. I've cut aluminium with it as deep as the blade and all sorts. If it was a 'real' saw i'd be fairly cautious doing that due to kickback, but the thing has such little torque that it just stalls out if it's pushed too hard.
Title: Re: Banjo Build
Post by: S. Heslop on June 18, 2015, 03:54:31 PM
Was looking up swaging, more for something to watch really, and found a video of a guy getting some use out of cold chisels.

t=4m56s
Title: Re: Banjo Build
Post by: Bluechip on June 18, 2015, 05:28:55 PM
When I first started work the electrical fitters had rotating vices, something like this:

http://www.bing.com/images/search?q=Columbian+Multi-Purpose+Vise&view=detailv2&&&id=88E2B88B420CF2527C96B80ABBE7F9BA935E8392&selectedIndex=1&ccid=s2kLOPVt&simid=608054480797764682&thid=JN.TuUXdmhOWsGz0X9RV7iYKQ&ajaxhist=0

I thought they were Paramo make, but I can't find a piccy so maybe not ... someone will know.

There is one in Machine Mart but I don't have much confidence in some of their stuff ...  :( but maybe they are OK ??? Reviews seem to be happy enough.

https://www.machinemart.co.uk/shop/product/details/clarke-cmv140-multi-purpose-cast-iron-vice
Title: Re: Banjo Build
Post by: vtsteam on June 18, 2015, 08:03:07 PM
I have one of those. They rotate in the fore'n'aft axis unless you tighten the jaws . I don't like that so much. It would be better if there was a lock for any particular angle, but as soon as you slack the jaws it can shift. And if you don't tighten enough it also rotates while working on something. I don't use the rotate feature much, other than to swing it 180 and bring the pipe jaws up. However, these aren't too good either because they are located in the center of the vise and are loose pieces. So only suitable for a long piece of pipe. You can't saw a short length.

I'm glad I have the vise because it is large and heavy, but the rotating features aren't the selling point for me.
Title: Re: Banjo Build
Post by: Bluechip on June 19, 2015, 03:40:19 AM
I think I did a poor choice of pic. The ones I occasionally used could be locked with a handle on the side, somewhat like a tailstock. So, if there was a piece in the jaws it stayed put.

Nor do I remember pipe grips ...  :scratch:  IIRC one end was the general jaws and the other had grooves like some machine vices.

It may be that they were produced by or for the works. At that time Derby had foundries and engineering outfits all over the place, it wouldn't be a big deal to have bespoke kit like that made... 

I do remember being shown that making an angled cut was easier if the job was tilted to make the cut vertical.

Anyway, it was not my principal area so I didn't spend much time in there..  :zap:  which was probably a relief to those who did ....

Dave
Title: Re: Banjo Build
Post by: S. Heslop on June 19, 2015, 08:30:47 AM
Forging.

(http://iforce.co.nz/i/3ow3uo4o.szy.jpg)
Was alot of work shaping this, since it's the classic case of if you move one thing the rest moves too. Lots of back and forth trying to find a satisfactory medium and get it close enough.

(http://iforce.co.nz/i/sfir1xsh.mvn.jpg)
I went around the garage looking for something to make an anvil stand from. At one point I was considering welding a small temporary extension to the bottom of my metal melting furnace, but I found these... car holder-uppers that haven't been used in 20 years. Not since a younger me managed to accidentally drain the oil from the hydraulic jack. It worked very well.

(http://iforce.co.nz/i/j5fgoms4.cb3.jpg)
Got the thing close enough. The tang end is twisted but most of that will be easy to correct when I cut the tang.

(http://iforce.co.nz/i/e4yjhsfe.hl3.jpg)
I spent alot of time working the transition from curved to flat, trying to get it straight, to the point that the metal bulged out. I think really I probably should've just made the whole thing curved to make life easier, but you don't get alot of time to think when playing with hot metal!

Edit: I forgot all about attaching the pictures. I should get back in the habit.
Title: Re: Banjo Build
Post by: S. Heslop on June 19, 2015, 04:38:50 PM
Butchered that cold chisel, also overheated it cutting the bulk out with the angle grinder, so I re-hardened it. The process knocked the rust off the shank and I can now see it's an Eclipse, made in England. Which as far as I know is good quality. I perhaps should've waited for the boot sale and picked up some smaller, more suitable chisels, but I'm hoping i'll be able to get everything ready to attempt case hardening on Sunday.

I left it rock hard but the tip cracked off. Then I over-tempered it I think and it's now back to too soft. I'll have a go at hardening it again tomorrow.
Title: Re: Banjo Build
Post by: S. Heslop on June 20, 2015, 07:54:05 AM
Really wasted that cold chisel. Just, on a whim, decided to try heating up that original bit of drill rod as hot as I could get it before quenching. I'd say it was getting towards yellow when it wasn't getting any hotter. And it hardened. Maybe all this time I just wasn't getting the metal hot enough, the non magnetic point (and a bit beyond) didn't seem to work. Nor was 'cherry' heat.

Been practicing putting teeth into a bit of bar and i'm a little worried about mucking up the real thing, so i'm putting it off. I'm also considering how to best support it. I've got a fair bit of lead i've been thinking about melting into the hollow. Or I could just relocate the vise on top of my Stump and hold it in that. It's arched so i'd assume it'd be fairly stiff if just clamped in a vise.
Title: Re: Banjo Build
Post by: S. Heslop on June 20, 2015, 02:04:58 PM
(http://iforce.co.nz/i/x4hmpgea.1uo.jpg)
I think I now realise why that photo I posted a while back of the chisels had a pile of about 6 of them. They tend to go dull fairly quickly. I spent a bit trying to find a good medium between so hard the tip cracks off and too soft, and I could do about 3 rows on average before the chisel needed regrinding.

(http://iforce.co.nz/i/fefvlsdu.jgh.jpg)
Got half of it done. I didn't get the orientation right for alot of them, they're all over the place, but I'd blame this on the way I was sitting. Towards the end I went and got a taller chair so the thing wasn't at shoulder height.

Also the teeth aren't pretty, some are higher than others and there's quite a long... I guess i'd call it a scoop? I think if I ground the chisel to have more of a back rake it'd produce better teeth but one I had it working at all I was happy enough.

Gonna do the other half but I wasn't able to get any fire clay for tomorrow, so I might end up doing it Monday. At the boot sale i'm gonna try and look out for some sort of blower. I usually see a fair amount of bouncy castle blowers and hopefully i'll get lucky.
Title: Re: Banjo Build
Post by: awemawson on June 20, 2015, 03:12:20 PM
 Looks good Simon :thumbup:

If the chisel's only lasting a few rows, either the embryo rasp is too hard or the chisel is too soft I reckon. (Says he who's never made a rasp in all his life !!)
Title: Re: Banjo Build
Post by: S. Heslop on June 20, 2015, 03:19:19 PM
I think it also might be that the chisel steel wasn't water hardening, since I can see a big vertical crack along the front of it. Could be full of loads of tiny fissures that're making some of the tips chip off easily. When I said on average I really should've been more specific and said that sometimes it lasts a couple of teeth before cracking off and sometimes it lasts a whole bunch of rows. Either way, it seems to be working well enough and I haven't found it too much of a hassle to keep touching it up.

At some point i'm probably going to use the gas forge again to harden the flat rasp, and i'll give that rebar another go at hardening since perhaps I just wasn't getting it hot enough too.
Title: Re: Banjo Build
Post by: awemawson on June 20, 2015, 03:26:37 PM
If I get the odd ten minutes I'll try hardening a bit of the same rebar - but things are getting a bit manic here at the moment  :bugeye:
Title: Re: Banjo Build
Post by: S. Heslop on June 21, 2015, 11:37:07 AM
Don't worry about it too much. I'll be testing it myself on... Tuesday?

Got the mild steel fully en-rasped. Not the most even of patterns but i'm gonna pretend I was going for random teeth.  Hopefully the teeth won't just burn off in case hardening.

(http://iforce.co.nz/i/nb34gusb.33o.jpg)
The chisel kept losing its tip until at about a quarter in it lasted the rest of the way. Kinda odd. Maybe the way it was tempered I was just slowly moving back through different tempering zones as I ground the front away, and eventually hit the one that was about right. Or maybe I found a bit that wasn't full of cracks. I also ground more of a back relief into it to get the teeth looking a bit better (on the far side in this photo so they're kinda hard to see, but they look more like the rasp teeth in photos of real ones).


Also gave it a quick test with two sheepish strokes.

(http://iforce.co.nz/i/rbrmruet.ssm.jpg)

It's just softwood but the teeth do seem to be cutting.
Title: Re: Banjo Build
Post by: S. Heslop on June 23, 2015, 01:23:54 PM
(http://iforce.co.nz/i/n1d3i0qv.oas.jpg)
Got the teeth in the flat rasp. Had a similar occurrence with the chisel repeatedly breaking at the start, then for the entire last half it lasted fine. I was sort of giving a chance to rest the hammer arm when grinding, so doing all the teeth one after another I eventually found (remembered) that it's better to just let the hammer drop rather than try and swing it. Definitely easier on the arm do to it that way. Had the handle tucked under my armpit and held it right towards the head.

(http://iforce.co.nz/i/io0jpzbo.1qh.jpg)
Then got it hot and quenched it. I covered it with soap from a bar and it seemed to protect it. I'm still trying to think about how and why that worked. My guess is that it coated the surface with a mix of soot and sodium oxide and kept oxygen away. Edit: That's probably nonsense, any sodium oxide being made would probably instantly react with water in the air/ exhaust. And I imagine sodium hydroxide would be evaporating at that temperature.

It protected it very well because I tipped the quenching tank (bit of pipe shoved into a plastic cup) over 3 times, so it was glowing hot for a considerable amount of time.

(http://iforce.co.nz/i/42132w53.2m0.jpg)
After a scrub, there's still a bit of scale and pitting but the teeth are mostly intact. You can see some cracks on the right hand side. Hopefully it won't cause the thing to shear off at some point.

(http://iforce.co.nz/i/0ycfnwcg.xrw.jpg)

Went all around Consett today trying to find some hydrochloric acid. I've heard it's used in alot of things, as brick cleaner and a pool water additive mostly, but I couldn't find any. For etching it I could use vinegar or citric acid, but I was hoping for something quicker. The funny part is that it'd be quicker to just leave it in vinegar overnight than continue searching for the stuff, but I sort of want to keep a closer eye on the process over an hour or so.
Title: Re: Banjo Build
Post by: chipenter on June 23, 2015, 02:10:06 PM
for brick cleaner try a builders merchant , for salfuric acid a auto factors .
Title: Re: Banjo Build
Post by: S. Heslop on June 23, 2015, 02:33:21 PM
Thanks. I don't know why I didn't think of battery acid for sulphuric.
Title: Re: Banjo Build
Post by: vtsteam on June 23, 2015, 02:37:47 PM
Wouldn't using it clean any wire edge up? Just like stropping. Doesn't look like much scale at all, and I'm afraid the acid will actually eat the sharpness off the tips of the teeth.
Title: Re: Banjo Build
Post by: S. Heslop on June 23, 2015, 03:24:44 PM
Wouldn't using it clean any wire edge up? Just like stropping. Doesn't look like much scale at all, and I'm afraid the acid will actually eat the sharpness off the tips of the teeth.

It's not for the scale, but to sharpen it. I believe that before sand blasting files were sharpened with acid. It's also something people use to resharpen old files and rasps.

Either way, i'm going to test it first before risking the rasps.
Title: Re: Banjo Build
Post by: DavidA on June 24, 2015, 04:18:13 PM
I'm clearly missing something here.

But why go to all this effort to make something like a rasp when you can buy them.

Surely the cost in time alone is many times the cost of a new one.

Dave. :scratch:
Title: Re: Banjo Build
Post by: vtsteam on June 24, 2015, 04:39:42 PM
David, there are many reasons for making things you can buy, from understanding how things work, building skills, learning about the history of toolmaking, learning associated processes amd material properties, taking on a challenge, and possibl producing something better for your needs than what you can buy. Rasps, by the way, aren't always cheap. Certainly not handmade custom shaped types.

Smon, my understanding is that the "sharpening" of new files by sandblasting is a sharpening step, not necessarily what we mean more generally as "sharpening", and that particular step is the removal of the wire edge after forming the actual point. A strop is used for the same thing on straight razors and similar processes on other edged tools. The strop doesn't actually sharpen by refining a point using an abrasive -- it's just leather and the blade is run backwards over it, it breaks of a tiny bit of excess past the end of the tip. I believe that's what the sandblasting does.
Title: Re: Banjo Build
Post by: S. Heslop on June 24, 2015, 08:28:52 PM
I ran a test with vinegar on one of those tang cutoffs overnight and it didn't seem to sharpen the teeth more than they already are. And the rasp does cut fine as it is. So yeah i'm probably going too far with it.

You're also right about why i'm making rasps. It's partly something to do, but it also gives me a chance to try out a few things i've wanted to for a while. Although i'm sure what i've produced isn't any better than what you can buy.

Still waiting on good weather to try case hardening. In the meantime I might start actually working on the neck. It's still a good bit away from the point where i'd even need the rasps. Carving it round seems to be the last step since the earlier ones are obviously easier if the thing is still square.
Title: Re: Banjo Build
Post by: S. Heslop on June 25, 2015, 03:44:40 PM
Spent today sorting the tablesaw out. It's always been about half a degree off square since I made it, and it's one of those things I figured i'd sort out when it became a problem. Had to remove a bit of material from one of the parts, and the new rasp came in handy for that. I also sorted out the fence, which had alot of flex. It's still got some flex but it's alot more solid than it was.

Cut some strips. There's still saw marks on them but i'm blaming the cheap blade i've always been using. Sometimes I think about getting a fancy blade, but they're so damn expensive.

(http://iforce.co.nz/i/k2xcadjr.nda.jpg)

The idea for the fingerboard is to make it up from strips in some sort of pattern. There's probably a good reason why people tend not to make fingerboards this way, but I guess i'll find out why when it's done. I'm mostly doing it this way since i've got no wood left that's long enough to make a fingerboard from.

(http://iforce.co.nz/i/psrxblll.fnk.jpg)

The obvious problem with this is that it's gonna be a hell of a thing to glue up. The strips are coming out about +/- .1mm and that's probably enough to cause some problems. I think most likely i'll make up some sort of fixture to clamp them about two strips wide at a time, so I can joint those to glue the whole thing.


Also, I spooked myself by measuring the neck on my existing banjo (which i'm mostly copying for proportions) and finding I was off by about 40mm. The dotted line on that diagram above is where the neck should really end. I've tripple checked the measurements now and it's just puzzling me how i'd be that far off in the first place.
Title: Re: Banjo Build
Post by: S. Heslop on June 26, 2015, 10:45:32 AM
(http://iforce.co.nz/i/fljbtnsb.ec5.jpg)
This drum sander is the best thing I ever built. I'm getting alot of use out of it. Here i'm thicknessing the boards because they came out with half a millimeter's difference.

(http://iforce.co.nz/i/ojafbt44.oki.jpg)
Then they were trimmed to about 100mm long.

(http://iforce.co.nz/i/m3nl5og3.3vg.jpg)
Got just enough of them.

(http://iforce.co.nz/i/hnatoyrx.20x.jpg)
Then glued up in rows of two. It's a bit of a weird setup, got little wedges applying the pressure (with a thin stick in between to hopefully even the pressure out), and at the edges ive got more wedges in an attempt to force... down the columns? It's hard to see how well it worked with glue obscuring it all, but I'll find out when it's done. There's also waxed paper tacked all over to stop them from sticking to what they're not supposed to.

I think they're guaranteed to have some gaps, but hopefully nothing too bad.
Title: Re: Banjo Build
Post by: S. Heslop on June 27, 2015, 01:32:34 PM
Finished gluing it up.

(http://iforce.co.nz/i/ra2dbwq5.imw.jpg)
Ran it over the jointer a few times to partially even the surface up. The glue is still a bit damp so I didn't go all the way. Just enough to see if it worked.

(http://iforce.co.nz/i/hcp1oeka.gst.jpg)
Plenty of gaps but it's still alot better than i'd expected. You can see the steps aren't quite even too, since the stops I had moved a bit. But the sticks are 6mm wide so it's not as noticeable as in this photo.
Title: Re: Banjo Build
Post by: RussellT on June 27, 2015, 03:50:44 PM
That looks good  :clap: :thumbup:

Do you think it would look even better if you'd alternated the strips across the neck as well.  Perhaps you could take it to bits and try gluing it up that way instead. :lol:

Russell
Title: Re: Banjo Build
Post by: S. Heslop on June 27, 2015, 06:40:28 PM
That looks good  :clap: :thumbup:

Do you think it would look even better if you'd alternated the strips across the neck as well.  Perhaps you could take it to bits and try gluing it up that way instead. :lol:

Russell

I tried a few arrangements in software to see what worked, and tried that too, but it looked a bit weird. It does also seem weird to cut all these strips and not do anything too fancy with them.

But like a true artist, i've been trying to cleverly justify this arrangement after already deciding on it. And i'm going with "it helps emphasize the asymmetry inherent to the banjo".
Title: Re: Banjo Build
Post by: S. Heslop on June 28, 2015, 01:13:16 PM
(http://iforce.co.nz/i/tbrmjuxj.0hx.jpg)
Tidied the fingerboard up a bit more.

(http://iforce.co.nz/i/pjwg1um1.g5v.jpg)
And started working on the neck proper. There's alot of things to do with it to turn it into a neck, of course, but i'm fussing over what order to do it all in. It's alot to keep track of. First I need to get that angled face looking a bit better, and that's going to require getting ahold of some MDF I figure to make a thing to sand it.

I'm mostly following what the guy is doing in these videos.


Title: Re: Banjo Build
Post by: micktoon on June 28, 2015, 06:52:34 PM
Hi Simon , the joins look really neat , just had a look at the sanding jig, simple but effective  :thumbup:  Keep up the good work .
 Cheers Mick
Title: Re: Banjo Build
Post by: S. Heslop on June 30, 2015, 05:23:40 PM
Hi Simon , the joins look really neat , just had a look at the sanding jig, simple but effective  :thumbup:  Keep up the good work .
 Cheers Mick

Thanks! The joints seemed real bad on the surface, but look alot better planed down a bit. Still some gaps though.

Haven't gotten alot done the last couple days since i've caught yet another lung infection. Just in time for the hottest damn day.

(http://iforce.co.nz/i/5xskcmsq.y2t.jpg)
Got that thing made up though and the angle sanded.
Title: Re: Banjo Build
Post by: AdeV on June 30, 2015, 08:43:03 PM
There's some really great work here, I am in awe of woodworkers, I don't know how you can cope with the damn stuff. Floppy as anything, won't hold an edge, splinters if you so much as look at it funny.... ugh, give me a nice piece of ali or steel any day of the week...

Regarding the 40mm overshoot on the fingerboard - is it too late to turn it into a banjo bass? Or maybe a tenor if bass is a bit too much of a stretch  :D
Title: Re: Banjo Build
Post by: S. Heslop on July 17, 2015, 11:24:34 AM
There's some really great work here, I am in awe of woodworkers, I don't know how you can cope with the damn stuff. Floppy as anything, won't hold an edge, splinters if you so much as look at it funny.... ugh, give me a nice piece of ali or steel any day of the week...

Regarding the 40mm overshoot on the fingerboard - is it too late to turn it into a banjo bass? Or maybe a tenor if bass is a bit too much of a stretch  :D

I used to hate the stuff too. Plywoods and other engineered woods helped ease me in since they're much easier to work with. I guess the big boon is that it's easy to cut and fairly light. Cheap too!

A few days ago I thought i'd go nuts and spend some intense time working on this. But I tidied the garage up and then had a rough evening with the bronchitis from the dust I disturbed just moving things about. I can get in with the respirator but it's not particularly pleasant to wear for long periods of time.

Anyways I did a bit playing with shellac today. Trying a few things on filling the grain.

(http://iforce.co.nz/i/zz3m4l52.422.jpg)
For this bit I used a slurry of sanding dust and shellac to try push into the grain.

(http://iforce.co.nz/i/35xx5xfg.hvk.jpg)
And for this I just put some real thick coats on. Both were sanded after every few layers, and I've got about 12 layers in total.

(http://iforce.co.nz/i/hnib5yua.p1e.jpg)
Neither seemed to work ideally, but the slurry worked best. I'm not entirely fussed about how it looks, but I figure on the back of the neck the grain will need to be filled so it doesn't fill up with dead skin and grease from my disgusting hands.

I think it'd probably be easiest to just buy some paste wood filler and fill the grain that way, instead of trying to do anything clever.
Title: Re: Banjo Build
Post by: awemawson on July 17, 2015, 12:42:18 PM
I'm no woodworker, but I do seem to remember 'grain filler' made up from knotting filler diluted with solvent and a bit of dye added to match the colour.
Title: Re: Banjo Build
Post by: Swarfing on July 17, 2015, 01:18:47 PM
To fill the grain you would be better off putting lots of layers of your finish and sanding back between coats. Better than losing the beauty of the wood.
Title: Re: Banjo Build
Post by: S. Heslop on July 17, 2015, 04:08:52 PM
I'm no woodworker, but I do seem to remember 'grain filler' made up from knotting filler diluted with solvent and a bit of dye added to match the colour.

Yeah I think that's the right way to do it, I was just wondering if I could avoid buying something.

To fill the grain you would be better off putting lots of layers of your finish and sanding back between coats. Better than losing the beauty of the wood.

With any other varnish i'd agree, but this shellac stuff puts on absurdly thin layers. It's very thin stuff when mixed so you cant goop it on so easily. Plus I don't think this construction meranti and scrap walnut has too much by the way of beauty.
Title: Re: Banjo Build
Post by: krv3000 on July 17, 2015, 08:09:49 PM
hi well get sum clear casting resin its a bit like fibre glass resin you mix it in the same way but its culler less brush on leave to harden then sand off its mutch  harder than varnish and can be polish to a mirror finish
Title: Re: Banjo Build
Post by: S. Heslop on July 17, 2015, 08:16:10 PM
hi well get sum clear casting resin its a bit like fibre glass resin you mix it in the same way but its culler less brush on leave to harden then sand off its mutch  harder than varnish and can be polish to a mirror finish

I made a couple of model boats when I was 12, and the second one I coated in exactly that stuff from a recommendation. Perhaps I didn't mix it properly but it took years for it to stop feeling sticky to the touch, and I never could get any paint to stick to it. It'd probably work well if I knew what I was doing, but I think it'd be too risky.

Sorry to shoot down all these suggestions. I appreciate receiving them though, since it gives me more to fall back on if something doesn't work out. Plus they might come in handy in the future.
Title: Re: Banjo Build
Post by: krv3000 on July 17, 2015, 08:37:45 PM
not a problem if you used the fibre glass stuff for your boats I bet you used the pasts hardener in the clear casting kit its a liquid hardener and I ant had any problems with it the only thing you must do is ad the right amount of hardener to the resin as it gets hot in the Harding proses witch Leeds to cracking or try the clear two pack epoxy resin glue 1 a go at the 1 shop   
Title: Re: Banjo Build
Post by: awemawson on July 18, 2015, 02:07:38 AM
In my experience fiberglass resins set slightly tacky unless the air is excluded from the outer surface. There are special wax additives you can buy, but some cling film stolen from the kitchen works just as well  :lol:
Title: Re: Banjo Build
Post by: chipenter on July 18, 2015, 02:35:24 AM
Sanding sealer is just talk added to the varnish or lacker .
Title: Re: Banjo Build
Post by: S. Heslop on July 19, 2015, 11:23:35 AM
It's about time I did some actual woodwork.

(http://iforce.co.nz/i/lb3tqpun.ifg.jpg)
Rough cut the neck out.

(http://iforce.co.nz/i/24qqxzie.5kv.jpg)
Got some actual use out of the spindle sander getting the inside corners up to the line.

(http://iforce.co.nz/i/md2wobys.mh1.jpg)
The back edge was brought down with the spokeshave to remove bulk and a sanding block to level it out. Was checking it against the template i'd made from mdf. I took some video of that but had the camera in the wrong setting, recording some seriously low resolution stuff. I'm glad I noticed before cutting the neck out proper at least.

I was planning to sand the back with the belt sander but really it's not that accurate, the 'foot' of the sander is all kinds of crooked.

(http://iforce.co.nz/i/enw1mr5t.e1o.jpg)
Back of the headstock isn't levelled yet, I need to glue on the 'ears' that extend it sideways.

(http://iforce.co.nz/i/fx22dhzj.le1.jpg)
I also routed the truss rod channel and got it about 0.8mm off from the center, which isn't great. Spent ages setting the thing up too. It's also a fairly loose slot but that shouldn't be a problem.
Title: Re: Banjo Build
Post by: S. Heslop on July 19, 2015, 03:54:16 PM
(http://iforce.co.nz/i/geyj2o1k.jrk.jpg)
Glued the 'ears' on. I was planning to be fancy and match the grain direction, but I didn't have any bits long enough or tall enough to do that. So I glued some on with the grain running in another direction. It's probably gonna look like ass.

(http://iforce.co.nz/i/2gq1ptnw.z03.jpg)
So I figure some sort of face on the headstock would help make it look a little less ass. I dug through the box of wood and found two nice bits of matching burl. I've got a few fancy bits of wood but the guy that owned them before me had intended to use them as knife handles, evident from the outline traced, and had also drilled holes for the pins.

Anyways the bits of burl weren't big enough so I split them again.

(http://iforce.co.nz/i/u0x55eh3.bdc.jpg)
The edges weren't flat and needed 'jointing' on the tablesaw. Then it was more wedges to glue it.

(http://iforce.co.nz/i/dfgonvhg.0wx.jpg)
Stuck to a bit of MDF to send through the drum sander. Once again, i'm getting alot of use out of this machine.

(http://iforce.co.nz/i/lmjvdta2.ysk.jpg)
After a bit more hand sanding I got it pretty smooth. I was thinking i'd probably drill the center out and set some sort of metal emblem into it, or a coin, but I think the pattern matches up so well it'd probably be a shame to do that.
Title: Re: Banjo Build
Post by: awemawson on July 19, 2015, 05:16:30 PM
Very nice work on that burl Simon. You certainly set yourself some challenges  :bow:
Title: Re: Banjo Build
Post by: vtsteam on July 19, 2015, 06:06:18 PM
Liking the woodwork, Simon!

A few words on polyester and epoxy resins as finishes on wood:
Polyester (what most people call "fiberglass") resin has poor adhesion on wood, it also eventually yellows and becomes opaque if not protected from sunlight with a UV resistant varnish. There are "water clear" casting resins, but they aren't designed as thin finishes -- they are for casting. I'm sure it can be used where sunlight isn't strong for some interior purposes, but i wouldn't put it on a banjo.

Polyester laminating resins do not cure on the surface in the presence of air -- they are designed that way so the next layer of glass fiber roving or mat or cloth, whatever the schedule is, will adhere to the last one in the mold. The next layer of resin and catalyst will kick it hard, though will also have a sticky surface to accept the next layer.

The final layer of resin is called "finishing resin" and it does have wax added, as Andrew said, to block air, and allow a hard surface cure on the inside of the molded item. Finishing resin can be bought that way -- you don't have to add wax -- it's pre-waxed. It's no good for laminating of course, because the wax prevents further adhesion.

Epoxies also yellow and go milky opaque very quickly on exposure to sunlight-- even more quickly than polyesters. They are a poor choice for something that is finished bright where you want to see the wood.

Talc added to lacquer makes a fine sanding sealer under paint, however it isn't very clear or even and isn't good under a bright finish.

Here's what I would try for filling the meranti grain -- spread a very small amount of carpenter glue on a small patch of the surface, and then immediately, before it dries, sand with fine sandpaper. This mixes fine sawdust with the glue and wipes it into the grain divots, while removing it from the surface. The color will fit well, just slightly darker in the grain than the meranti, as it should be, but a good tonal match.

This also works well with small cracks in glue joints. There a trick to sanding enough, but not too much to fill what you want, and to sanding in the right direction to fill, and not pull out your filler material. But a little practice on scrap will show you what to do.

Hope that helps!
Title: Re: Banjo Build
Post by: S. Heslop on July 19, 2015, 06:48:11 PM
Polyester laminating resins do not cure on the surface in the presence of air -- they are designed that way so the next layer of glass fiber roving or mat or cloth, whatever the schedule is, will adhere to the last one in the mold. The next layer of resin and catalyst will kick it hard, though will also have a sticky surface to accept the next layer.

That's cool. I never knew that. I just always assumed I didn't add enough hardener to the fiberglass resin.

As for the glue and sanding thing, it seems similar to the (what people claim to be) old method of getting pumice embedded in the cloth wad you're applying shellac with and rubbing it a whole bunch over the surface and keeping it wet with shellac. It confused me at first since I thought people were filling the grain with pumice, but that stuff would show up as white. But I figure it's just sanding the surface and clogging the pores with the sawdust/ shellac mess. It seems like a long winded way to go about it.

But the thing i'd worry about glue is how well the shellac will stick to it. I'm thinking about testing it at some point, but I ran out of the mixed shellac (from the accordion) I had about.
Title: Re: Banjo Build
Post by: vtsteam on July 19, 2015, 09:13:26 PM
Simon, I use shellac a lot and also occasionally sanding to fill a problem glue line crack. There is basically no glue on the surface of the wood, it's only in the crack or grain. you use very little glue and the sandpaper removes it immediately. But, I've also never had a problem with shellac over glued joints, anyway. For that kind of work I usually use titebond 2 -- the yellow aliphatic type of glue -- seems fine with shellac.

I don't think this is similar to the rottenstone thing, which is part of getting  a fine rubbed shellac finish. Not filling grain.

Do try it on some scrap. I think you'll find it's no big deal. Try it on a bad joint with scrap and see the results. They do need to be level with eachother, at least, so sand them flush first. Use very little glue, and start sanding with a piece of paper in hand -- I dunno maybe 320 grit or so. Coarser if it goes too slow.

If I remember correctly I first sand crosswise to the joint. When it fills I stop, let dry, then sand with the grain to clean up. Sanding with the joint at first tends to pull the homemade sawdust putty back out. A little practice and you'll get the hang of it.
Title: Re: Banjo Build
Post by: S. Heslop on July 20, 2015, 06:34:36 PM
(http://iforce.co.nz/i/re0tq5d4.lwp.jpg)
Routed the fingerboard out, following an mdf template. Decided it probably doesn't need edgebanding. There's one spot that's not too great but it's alot of effort by the end of the day, and I don't have the materials on hand.

(http://iforce.co.nz/i/553ptgqo.hfa.jpg)
Finished off the truss rod too. Kinda bungled up the first attempt to stick nuts pairs on tightened against each other. So for the second I pinned them.

(http://iforce.co.nz/i/yqvwfan3.ut1.jpg)
It works.

I maybe could've gotten a bit more done, but i've been having alot of cramps lately and standing up for more than an hour wasn't doing me any favours. So I took a break and never got back to it. I think the cramps might be from stopping codeine since I think I remember the same thing happening in the past.
Title: Re: Banjo Build
Post by: S. Heslop on July 21, 2015, 03:45:37 PM
Wasn't a whole lot I could do today. Redid the truss rod since the part where the screw bulged out just meant id have to route more material out the neck, right at the part where I feel i'm cutting it close on how much i've already routed out.

Also thicknessed the fingerboard to 6mm.

For planing the back of the headstock I was at first gonna use a router with some rails to ride it on, but that'd require sticking the thing to the table... but I ran out of carpet tape. So plan B was to try using the drum sander. I needed something smooth to slide the neck on, and the ideal thing I thought would be a bit of glass. I had a bit that was just ever so slightly too wide. Not a big deal to trim a bit off.

(http://iforce.co.nz/i/3wkfqiqe.dvk.jpg)
Except it was reinforced glass. I should've figured, considering where it came from. What I thought was neat was that it kept crackling after it'd initially shattered, with new cracks appearing. Like a bowl of rice crispies.

(http://iforce.co.nz/i/cuct4i0q.eaw.jpg)
Anyways a bit of MDF worked fine. I'm not too keen on this idea though, it worked out okay but when removing the part it had a tendency to catch and get thrown out faster than expected. I wont't do it again if I can avoid it.

(http://iforce.co.nz/i/d2rvtqsz.ny4.jpg)
Smooth enough.  I'm not too worried about it looking ugly.

What i'm waiting on is a bearing to match a router bit i've got, to try make one of those bottom bearing follow routers. Almost all the rest of the tasks before carving require use of one of those.
Title: Re: Banjo Build
Post by: S. Heslop on July 22, 2015, 06:11:27 PM
The stuff arrived today. Got fretwire and bearings.

(http://iforce.co.nz/i/zt5nrioi.0rt.jpg)
Transmuted bottom bearing to top bearing, but squashed the top of it by mistake so it's irreversible.

(http://iforce.co.nz/i/g0pihly4.4to.jpg)
Also made a template for the peghead but I figured it'd probably be better to route that after getting the fingerboard stuck on. And there's a few things to do with that before then.

(http://iforce.co.nz/i/b5pldfxy.5wy.jpg)
For cutting the fret slots I'm using a hacksaw blade. It's set in a wooden block to give it more of a handle and to make it easier to keep it on target. I've got a whole thing planned but i'm finding it awkward to explain, so I guess i'll wait till i've got photos.

Anyways, not a whole lot done today. Spent most of it outside, and the first thing I did when I got back was epoxy that hacksaw blade. But I got the slow setting kind of epoxy (to make the brass tube stuff later easier, hopefully) and it'll probably be an overnight thing.
Title: Re: Banjo Build
Post by: S. Heslop on July 23, 2015, 10:56:57 AM
It exploded.

(http://iforce.co.nz/i/cok3nxzc.cpj.jpg)
(http://iforce.co.nz/i/wmgd4xjh.5lc.jpg)

I'm lucky the lid didn't hit me in the face because I was right over it, i'm lucky that the charcoal powder inside hadn't gotten hot enough to burn me, and i'm lucky I had my goggles on. But despite all that i'm still disappointed I wasn't recording it.
Title: Re: Banjo Build
Post by: NormanV on July 23, 2015, 11:27:18 AM
Simon, you are very honest with your posts, even if they make you look silly. That's a great portrait of you, worth keeping.
I have kept my silliness to myself but in order to redress the balance I will divulge some of my own stupidity. (Not that I am trying to imply that you are stupid.)
After pouring an aluminium casting I had poured the surplus into a loaf tin to make an ingot. In tidying up I picked up a firebrick to put it in a safe place and managed to drop it onto the edge of the loaf tin, molten aluminium flew in all directions, a large dollop falling on my shoe. Fortunately it was leather and didn't melt or burst into flames, I was able to flick it off and no harm was done, not even to the shoe. But this is where my stupidity comes in, I was wearing shorts, I was so lucky. I will wear proper protective clothing in future.
Title: Re: Banjo Build
Post by: AdeV on July 23, 2015, 11:36:01 AM
Are you sure you're not the Batman?

Seriously - I'm with Norman on this one - thanks for sharing, it's a timely reminder that some of the stuff we do is quite dangerous...

Speaking of which, what actually were you doing? I must have missed the post where you were making a charcoal bomb?
Title: Re: Banjo Build
Post by: Lew_Merrick_PE on July 23, 2015, 12:42:12 PM
Hi Simon,

A couple of question/comments:  (1) Banjo pegheads are traditionally cut with the "sides" perpendicular to the fretboard face (unlike guitar pegheads).  (2) What size fret wire are you using that allows you to use a hacksaw blade to cut the slots?  The wire I use requires a .026 to .030 (inch) slot width in ebony.  As your fretboard is made of softer woods, I would postulate a narrower slot requirement.
Title: Re: Banjo Build
Post by: nrml on July 23, 2015, 01:18:45 PM
I've been silently following this thread all along. I am glad you came through that unscathed :jaw:. Thanks for posting the pictures as a reminder to everyone not to cut corners where safety is concerned. We are all guilty of it from time to time.
Title: Re: Banjo Build
Post by: S. Heslop on July 23, 2015, 02:41:40 PM
Are you sure you're not the Batman?

Seriously - I'm with Norman on this one - thanks for sharing, it's a timely reminder that some of the stuff we do is quite dangerous...

Speaking of which, what actually were you doing? I must have missed the post where you were making a charcoal bomb?

I was trying to case harden. The idea is to seal the thing in a canister packed with charcoal and get it hot. Obviously gasses will probably be released, and internal pressures would increase. To try deal with this I only sealed the canister with some fire cement, since bolting it down would make a quite literal bomb. I suppose the fire cement did what it was supposed to, but I didn't imagine it'd be so sudden and dramatic.

I think if I were to do it again, i'd probably either drill a pinhole into the top of the canister, or i'd leave a small gap in the fire cement seal. Although if I was to really do it again, i'd go about building an electric furnace. The big reason I avoided doing so is because I just don't have the space.

Hi Simon,

A couple of question/comments:  (1) Banjo pegheads are traditionally cut with the "sides" perpendicular to the fretboard face (unlike guitar pegheads).  (2) What size fret wire are you using that allows you to use a hacksaw blade to cut the slots?  The wire I use requires a .026 to .030 (inch) slot width in ebony.  As your fretboard is made of softer woods, I would postulate a narrower slot requirement.

Don't quite know what you mean with the banjo peghead sides.

For the fretwire the tang is about 0.8mm wide. The hacksaw blade is a junior hacksaw blade and is about 0.6mm wide, measured from the teeth (to account for the set, hopefully). It probably cuts a wider slot, but I did a test slot to see if it was suitable and it took alot of force to remove the fret wire. Enough that it teared the wood out from the sides of the slot. I've heard that putting a slight bevel on the fret slots can help prevent that from happening if you ever need to re-fret the instrument.
Title: Re: Banjo Build
Post by: tom osselton on July 23, 2015, 03:15:36 PM
Glad your ok! That is the last thing I would expect to happen!
Title: Re: Banjo Build
Post by: Lew_Merrick_PE on July 23, 2015, 03:28:04 PM
Don't quite know what you mean with the banjo peghead sides.

Normally (at least on this side of the pond) a banjo's peghead is cut with the fretboard face held to the jigsaw or bandsaw table as the contour is cut.

For the fretwire the tang is about 0.8mm wide. The hacksaw blade is a junior hacksaw blade and is about 0.6mm wide, measured from the teeth (to account for the set, hopefully). It probably cuts a wider slot, but I did a test slot to see if it was suitable and it took alot of force to remove the fret wire. Enough that it teared the wood out from the sides of the slot. I've heard that putting a slight bevel on the fret slots can help prevent that from happening if you ever need to re-fret the instrument.

I normally make classic or flamenco guitars and frailing banjos.  It sounds as if you have fret wire for an electric guitar.  ???
Title: Re: Banjo Build
Post by: S. Heslop on July 23, 2015, 05:13:59 PM
Normally (at least on this side of the pond) a banjo's peghead is cut with the fretboard face held to the jigsaw or bandsaw table as the contour is cut.

I normally make classic or flamenco guitars and frailing banjos.  It sounds as if you have fret wire for an electric guitar.  ???

Yeah I was considering cutting the peghead that way, I didn't know it was traditional I just thought it'd look cool. But with my bandsaw I think it would've been a difficult cut. Also usually banjos have funky heads but i'm going for something fairly basic here.

I was very tempted to go for this style of headstock.

(http://iforce.co.nz/i/xjguolbu.ze4.jpg)

It's one of those 'so stupid it's cool' sorts of things. Pompadour banjo. I think i'd only be allowed to play rock n roll with it.

But yeah following a template seems like it'd probably work out better. I'm a little concerned about routing endgrain though. I'll have to take it very slow.

As for the fret wire, I did buy it from a guitar place at about the same width as what my current (cheap) banjo has. But I can't imagine it'd make much of a difference. I imagine you could probably go a bit thinner with the stuff on a banjo, with the lighter strings. But my old banjo's frets are surprisingly worn after not a huge amount of playing, so I didn't want to take any chances.

Anyways I got the thing slotted.

(http://iforce.co.nz/i/r2ugtar5.w5y.jpg)
Being the most critical part of the banjo i'd naturally not given it alot of thought and came up with most of this stuff as I went along. I figured i'd use paper templates since they tend to be more accurate than a tape measure. But I wasn't sure how to attach it. Usually i'd use spray adhesive but I don't really want to have to sand it all off, since I was clever enough to get the fingerboard to exactly the final thickness before slotting it. I also didn't want to use the double sided tape since it'd probably gum up the saw blade and tear off while cutting. So I went with putting a few spots of tape to lightly adhere the template, then marking each slot with a chisel.

(http://iforce.co.nz/i/bh0r1fs2.l0t.jpg)
Was pleased the lines came out so visible. It's stuck to a bit of MDF to keep it lined up properly in the miter box.

(http://iforce.co.nz/i/ghefifef.fcs.jpg)
Got a sort of junk miter box that the saw butts up against. The cut is lined up by eye, by stooping down and getting the sawblade in line with my eye I could see the reflection on the wood below to line the cut up pretty well. A light backwards stroke with the saw also confirmed if I was on line or not.

Now if this is accurate or not, i'm not sure. There's probably an error in lining up the paper templates (that were in 3 parts for this), there's an error in marking the chisel line, and an error in lining up the sawblade to the mark. It could be a considerable ways off by the end of all that. But I think that, for the first 10 or so frets, being within 1mm of the intended position will probably be fine. I don't think i'd be that far out.

(http://iforce.co.nz/i/ig1o1ljs.aqg.jpg)
I had a hell of a time separating the MDF from the fretboard. The old carpet tape I had was more like duct tape and didn't stick all that well, but this new stuff is intense. Opened it a bit to begin with using a chisel then slipped this steel ruler in and hammered it down.

(http://iforce.co.nz/i/mduqqzwt.ahw.jpg)
Then used it like a knife to get the rest off. I flexed the fingerboard well past what i'd assumed it would've been able to survive, but i'm glad it didnt break.

(http://iforce.co.nz/i/xs2hyej0.5r5.jpg)
Before glueing it to the rest of the neck I need to put the 5th string in. I'm not entirely sure if I got the 5th string pip in the right place, and i'm a bit concerned about it really. It doesn't have to be exactly in line with the rest of the strings but hopefully its not so far over it interferes with the 4th string. Here i'm drilling the angled hole for the tube.

(http://iforce.co.nz/i/b54brgot.nmt.jpg)
A slot was routed out on the other side. Rather than route it deeper I decided to squash the tube a bit in the vise. Checked it still guided the string, then fit it to the recess and fit the recess to the tube. It was then epoxied in. More of the slow stuff, so it'll be a while till it sets.

This epoxy sets very flexible. Usually that'd be a good thing but it might make it harder to trim flush.
Title: Re: Banjo Build
Post by: vtsteam on July 23, 2015, 09:24:37 PM
I was trying to case harden. The idea is to seal the thing in a canister packed with charcoal and get it hot. Obviously gasses will probably be released, and internal pressures would increase. To try deal with this I only sealed the canister with some fire cement, since bolting it down would make a quite literal bomb. I suppose the fire cement did what it was supposed to, but I didn't imagine it'd be so sudden and dramatic.

Glad you're okay, Simon. That must have been a shock. I always wear a welding helmet with a clear lens when working with the furnace, and lull length leather welders cape and leather apron for cast iron, even if it's hot out. I'll remember to do the same if I ever pack harden.

BTW I've heard "fire clay" for luting, not "fire cement" The first is water mix would be fairly porous and have low adhesion to the steel. Fire cement on the other hand is fire clay mixed with sodium silicate -- is much harder, non-porous and a strong binder to steel. It would bake into a hard plug.
Title: Re: Banjo Build
Post by: SwarfnStuff on July 24, 2015, 03:35:31 AM
I too am glad you survived to tell the tale Simon. As I understand things forget the pin-hole If you try again. Go with at least 1/4" AKA 6mm hole. You will be generating gas and the air inside will be expanding rapidly with your furnace heat. Atmospheric air will not be in a rush to get in there until things cool down when it won't matter as I understand it.
John B
Title: Re: Banjo Build
Post by: S. Heslop on July 24, 2015, 06:02:17 AM
I was trying to case harden. The idea is to seal the thing in a canister packed with charcoal and get it hot. Obviously gasses will probably be released, and internal pressures would increase. To try deal with this I only sealed the canister with some fire cement, since bolting it down would make a quite literal bomb. I suppose the fire cement did what it was supposed to, but I didn't imagine it'd be so sudden and dramatic.

Glad you're okay, Simon. That must have been a shock. I always wear a welding helmet with a clear lens when working with the furnace, and lull length leather welders cape and leather apron for cast iron, even if it's hot out. I'll remember to do the same if I ever pack harden.

BTW I've heard "fire clay" for luting, not "fire cement" The first is water mix would be fairly porous and have low adhesion to the steel. Fire cement on the other hand is fire clay mixed with sodium silicate -- is much harder, non-porous and a strong binder to steel. It would bake into a hard plug.

I've got a face shield I'd usually break out, but it's that running around getting everything set up, and then trying to keep on top of it all that makes me forget stuff like that. I forgot the welding gloves at first too. Also I did wonder with the fire clay/ cement thing. I couldn't find fire clay anywhere nearby so I went with the cement.
Title: Re: Banjo Build
Post by: S. Heslop on July 24, 2015, 12:34:37 PM
(http://iforce.co.nz/i/vo3k1dyc.dlr.jpg)
Looks pretty good, but what's that?

(http://iforce.co.nz/i/adraynqa.avv.jpg)
Oh...

I raised the router table so high that the collet nut was above the table and it took me a while to figure out why it wasn't cutting so easily, and why I could smell wood burning. I thought that maybe the router bit had gotten dull.

I had some important words to say after seeing that, thinking I might've irreversibly wrecked the project. But I think I might be able to get away with some edge binding. I'll need to get a new router bit though.

Really thought I was on course for getting this finished by Sunday, at least without the finish.
Title: Re: Banjo Build
Post by: vtsteam on July 24, 2015, 11:13:44 PM
Simon I always seem to have bad luck with a router! I remember once rounding over the sheer clamp on a dory skiff i had built -- the topsides were painted, this rail was going to be finished bright -- I just needed to round it.

As I was going along, the bit raised a splinter, in a split second the router bit pin followed it in diagonally across the whote rail, pulling through the planking and all. The rail relieved of tension split and snapped out away from the topsides for a couple feet forward of the cut. What a mess! My new boat looked like somebody had taken a sledgehammer to the side!

I've had many router mishaps since, though none so serious, just ruined a lot of work -- I just don't trust the damn things. And they'e probably one of the most unpleasant tools to run ever invented. Loud and lookin for trouble! I'd ten times rather run a chainsaw than a router. Well I know many people use them every day with little problem. I just don't get along with them.

re. fire clay for luting: since case hardening temps aren't iron melting temps and the luting is temporary , I would guess that ordinary clays other than fireclay might work as well. But I don't think furnace cement is a good idea.
Title: Re: Banjo Build
Post by: S. Heslop on July 25, 2015, 01:26:13 AM
Yeah I know what you mean. I'm still hesitant to use a hand router. I bought a fairly fancy one a while back, the kind with a cylindrical body (that are hard to get ahold of in the UK), for another project that probably won't go anywhere. But I can't see myself getting a whole load of use out of it as is.

The router table though has made it much more controllable. But of course you can only route what you can fit onto the table...
Title: Re: Banjo Build
Post by: S. Heslop on July 25, 2015, 03:54:38 PM
Too many pictures in this post. I got carried away.

Put holes in the peghead using the template to locate.
(http://iforce.co.nz/i/fcv4war3.1it.jpg)
(http://iforce.co.nz/i/jcci5s5m.pkk.jpg)
Plenty of tearout though. The trick is to never drill all the way through with forstner bits, but drill from the other side (if possible) once the point of it starts poking through. I forgot though. Plus with the extra thickness of the burl face the peghead was too thick for the tuning machines. So I trimmed it further in the drum sander like before, in the way I said I wouldn't do again... but I did this right after id mucked the neck up so I figured it wouldn't be a big loss if it got flung out through the window or something.

(http://iforce.co.nz/i/gubxhw1v.er0.jpg)
Anyways that didn't happen.


Onto fixing yesterdays mistake. I decided edge binding would be the way to go, but didn't want to go searching for suitable plastics at a reasonable price, or wait for delivery on the 'proper' stuff.
 
(http://iforce.co.nz/i/lmrdanul.cq5.jpg)
So I cut this black ABS pipe I had bought for dust collection but never actually used.

(http://iforce.co.nz/i/1bti3e3k.w0f.jpg)
Then got it soft with the brand new iron (hence the wax paper).

(http://iforce.co.nz/i/fkipeapu.gts.jpg)
Clamped a flat board on it.

(http://iforce.co.nz/i/nmmou3p5.uow.jpg)
And it came out surprisingly flat with no curling back.

(http://iforce.co.nz/i/y3dfe1sy.j0g.jpg)
For routing the recess I made a... ring I guess you'd call it, for the bearing. To give about a 2.5mm depth of cut. I forget what the router bit originally was but I bought it for the drum sander.

I was originally going to try increasing the thickness of the ABS pipe material (which was about 2mm thick) by superglueing two bits together, but that didn't quite work out so well (it delaminated easily in a test), so I decided to rout to a lesser depth by putting a few layers of masking tape on the side of the wood where the bearing rides.

(http://iforce.co.nz/i/w3ub5pjz.i4.jpg)
I don't often use superglue but I quite like how it waits for you. As far as I know it sets when no air can get to it. So it wasn't a problem gluing this much at a time.

(http://iforce.co.nz/i/sruc2gmj.jcb.jpg)
Masking tape holds it on as it dries. It dries pretty fast but my fingers couldn't cover the whole thing.

(http://iforce.co.nz/i/ld2zmcdw.nfa.jpg)
It was then scraped down. Masking tape is there to prevent me from gouging the surface like I did on the test piece.

(http://iforce.co.nz/i/1gshq1vy.scy.jpg)
The final bit was sanded flush since I needed to slightly flatten the neck a bit anyways. Had a tiny bit of an S curve.

(http://iforce.co.nz/i/v2f3k23i.s4v.jpg)
Looks pretty good for something that's just covering up a stupid mistake.

(http://iforce.co.nz/i/bufetv1q.vi4.jpg)
With the slightly lesser rout depth there's two spots that didn't get totally removed. I'm considering filling them, but I don't think they're particularly noticeable and they're far enough up the neck that i'm not worried about trying to bend strings into the divots.

(http://iforce.co.nz/i/j0mitf1r.tx4.jpg)
I also removed the material to get access to the truss rod adjustment. I'll probably make a truss rod cover out of more ABS pipe, but i'm still deciding on the shape. I'm also going to edge bind the headstock since I bungled the cut and went into it a bit. I'll have to be careful to not bungle it backwards into the stuff I just did.
Title: Re: Banjo Build
Post by: S. Heslop on July 25, 2015, 07:37:28 PM
Decided to do the headstock tonight too.

(http://iforce.co.nz/i/yxpridnt.dzh.jpg)
Lost my lighter and the blowtorch packed in.

(http://iforce.co.nz/i/qjsrw0zk.bn5.jpg)
Just passing it through the flame to warm it.

(http://iforce.co.nz/i/dog3yk3f.ya3.jpg)
So it's flexible enough to hold the shape. Whatever this plastic is, it holds its shape beautifully as it cools. No spring back at all.

(http://iforce.co.nz/i/ojq3qor5.eao.jpg)
Also cut the nut slot, perhaps a little too deep. I might glue a bit of wood back in.

(http://iforce.co.nz/i/nfprj3zl.i5f.jpg)
Gonna go with a brass nut, part because it's what I have, but i'm also interested to see how much a difference it makes. I'd imagine it'd probably wear faster than more traditional materials.
Title: Re: Banjo Build
Post by: vtsteam on July 25, 2015, 10:33:11 PM
I like the ironed flat ABS technique!

I've flattened 4" PVC pipe before in an electric utility oven with plenty of ventilation. Heating slowl is the key, but never thought of an iron.

I'm thinking a homemade solar oven might be interesting to try for that, since slow and relatively low temp would seem to suit.

The banjo is coming along great and I like all the setbacks and watching them overcome towards a beatuiful instrument.
Title: Re: Banjo Build
Post by: S. Heslop on July 26, 2015, 11:48:32 AM
I'd heard that carving the neck is probably the easiest part of making any stringed instrument, and i'm happy to say that it's indeed true.

(http://iforce.co.nz/i/0npcyogw.kdg.jpg)
Rasp worked well, but I probably would've done fine with just the coarse crosscut file.

(http://iforce.co.nz/i/5ge02aba.nfq.jpg)
There's alot of methods for carving necks it seems, but I liked the idea of this one; faceting the neck until it approximates the profile then smoothing it.

(http://iforce.co.nz/i/gdwqtqbi.hvr.jpg)
Although after the first facets I started to think 'who cares about getting it to the plan' and just carved away at it till it seemed about right. I'd say the faceting probably helped keep it even though.

This is also the first time i've gotten a scraper sharpened so well and it really pulled off a surprising amount of material. It's such a goofy tool in principle yet it works so well.

(http://iforce.co.nz/i/f5jqldyh.4ey.jpg)
After less than an hour I had it shaped and sanded. I didn't time myself but i'd guess it took about 30-40 minutes. It's kinda funny considering how much effort I put into assembling the whole gamut of carving tools.

(http://iforce.co.nz/i/1bamxmqp.bgn.jpg)
It's also hard to take a photo that shows the shape. I guess ideally i'd find somewhere with strong lighting from one direction, which I was trying to do in this photo with it down by the side of the router table.

Anyways, being an idiot I thought this would take up the whole day. So now i'm kinda sitting around trying to think of what to do next. Maybe figure out how to put the frets in. It's trickier now that i've got the edge binding in the way. I tried nipping the tangs off with some small side cutters but it bent the wire pretty bad and was tough getting it back. Everywhere I look online seems to recommend either fancy pants tooling or just carefully filing the tangs away, but I'm hoping to find something easier and cheaper.

They sell a fret tang nipper from stewmac that everyone seems to get real excited about, and it took a while to find a close-up video in action and it just seems to be a regular old hand nibbler. So i'm considering trying to make something like that.
Title: Re: Banjo Build
Post by: AdeV on July 26, 2015, 01:12:58 PM
Suddenly that's really starting to look like a lovely instrument... I'm sure it'll play as well as it looks.

Question - the frets, are they just a piece of relatively thick wire, or a specifically shaped extrusion? Like a thin flat bar? Either way, I'm assuming you cut them over-length, glue them in place, then file the hanging ends off? Or do you cut them, file them to length & glue them in that way? If the latter, then careful "filing" with a flap disk on an angle grinder would seem to be the obvious, and much faster, method of sizing them to length. I'd be tempted to make a jig - a simple block of wood with an accurately drilled hole, which traps the fret to the exact right depth; then simply angle grind flush to the block. A pair of small pliers might be needed to extract the finished fret, which is now the perfect length to glue in place.

If you glue them in then file them, I'd do it exactly the same way, except I'd probably put some masking tape on that plastic edging, to prevent scuffing.

Edit to add: A slightly modifed version of the above: Make the hole big enough to contain ALL of your frets (+ 2/3 spares); angle grind all to length, then either tap out or split the block to release them. Same result, but only one operation instead of a dozen or so...
Title: Re: Banjo Build
Post by: S. Heslop on July 26, 2015, 03:05:45 PM
Suddenly that's really starting to look like a lovely instrument... I'm sure it'll play as well as it looks.

Question - the frets, are they just a piece of relatively thick wire, or a specifically shaped extrusion? Like a thin flat bar? Either way, I'm assuming you cut them over-length, glue them in place, then file the hanging ends off? Or do you cut them, file them to length & glue them in that way? If the latter, then careful "filing" with a flap disk on an angle grinder would seem to be the obvious, and much faster, method of sizing them to length. I'd be tempted to make a jig - a simple block of wood with an accurately drilled hole, which traps the fret to the exact right depth; then simply angle grind flush to the block. A pair of small pliers might be needed to extract the finished fret, which is now the perfect length to glue in place.

If you glue them in then file them, I'd do it exactly the same way, except I'd probably put some masking tape on that plastic edging, to prevent scuffing.

Edit to add: A slightly modifed version of the above: Make the hole big enough to contain ALL of your frets (+ 2/3 spares); angle grind all to length, then either tap out or split the block to release them. Same result, but only one operation instead of a dozen or so...

Thanks. The fret wire is like an extrusion, somewhat of a mushroom cross section. The 'stalk' aka tang also has little barbs all the way down that grip into the wood. They're also made from fairly soft metal, German silver I think. And they are filed to length after sticking them in.

Also the problem isn't cutting them to length, but cutting out the tang where the edge-banding is. Since there's not a slot there, but the fret still needs to hang over it.

(http://iforce.co.nz/i/3avhrf5z.n0m.JPG)
Here's a picture to illustrate. It'll probably be easy enough to just file the tang away by hand in all honesty. But I've got an idea for a kind of block that could hold them, with tape over half of the file so it doesn't wear away the block where it contacts.
Title: Re: Banjo Build
Post by: nrml on July 26, 2015, 05:16:44 PM
The little gouge marks still left can be easily made invisible with those bits of coloured wax that are made for that purpose.
Title: Re: Banjo Build
Post by: S. Heslop on July 27, 2015, 04:41:17 PM
Got some brass today. Couldn't get the size I wanted at a reasonable price so I got another shape that still fit the parts. The original idea was that id be able to grind away part of the stuff with a burr in the router table but after what I learned today i'm not sure if that would've worked anyways.

(http://iforce.co.nz/i/qqkbokra.43g.jpg)
Made a little test shoe with the hacksaw and files. It has that hand-made charm~

Took way too long that way and is fairly ugly despite all the effort, and I wasn't so hot on the idea of doing 28 like that, so i'm definitely going to try doing it in an overly complicated but more entertaining way.

I first tried cutting it on the tablesaw but the cut was getting narrower, and I was blaming blade deflection. So I tried bandsawing it and had similar problems against a fence. Worked out better free-hand, but you can see the offcut curling away.

(http://iforce.co.nz/i/nu5vvwxt.pgz.jpg)
The bar itself was also curling away. Internal stresses I suppose. This was pulling it away from the fence and making the cut get narrower. I'd heard that this could happen but I always imagined it being a matter of a few thousandths, and nothing quite as dramatic as this. It also stayed fairly cool during the bandsaw cut so I don't think it was bending from heat expansion on one side.

(http://iforce.co.nz/i/s3tpsvuf.yvb.jpg)
I straightened it by pulling on it in the vise a bunch and sent it through the drum sander, but it bowed again while doing that and I didn't notice until i'd overshot the 10mm mark I was aiming for. Straightened it again and kept an eye on it, and it's now at about 9mm but still useable.

(http://iforce.co.nz/i/hwjjelab.x3b.jpg)
Then I hacksawed it off. Was originally going to use the tablesaw but the metal cutting blade didn't raise high enough, and the bandsaw didn't produce anywhere near a straight cut. Then I ganged them up in 5s (got away with 10 for the last... 10) to file a flat side to them, mostly just for referencing and to make drilling a hole easier.

It was alot of work and there's more to go. I'm still going to try using the burrs, by clamping them into a stack like in the above picture. Chances are the stack will explode and fling them all everywhere, but it's something I really want to try out regardless.
Title: Re: Banjo Build
Post by: vtsteam on July 27, 2015, 08:21:57 PM
It's acting like cold rolled steel, which, I suppose makes sense.

I wonder if you heated it up and plunged it (brass annealing process) first, if that would have relieved the internal stresses enough to saw straight on the band saw?
Title: Re: Banjo Build
Post by: S. Heslop on July 27, 2015, 09:39:05 PM
It's acting like cold rolled steel, which, I suppose makes sense.

I wonder if you heated it up and plunged it (brass annealing process) first, if that would have relieved the internal stresses enough to saw straight on the band saw?

I'm curious now too. I suppose I could've set that firebrick thing up again and slowly fed the bar through, it'd anneal just cooling in the air as well. But it's a bit late now.
Title: Re: Banjo Build
Post by: vtsteam on July 27, 2015, 09:41:08 PM
I believe that, unlike steel, you heat to red heat and plunge brass to anneal. Steel, of course hardens if you do that. But I think brass is opposite.
Title: Re: Banjo Build
Post by: S. Heslop on July 28, 2015, 06:09:26 AM
I believe that, unlike steel, you heat to red heat and plunge brass to anneal. Steel, of course hardens if you do that. But I think brass is opposite.

In the past i've just let stuff air cool, I figured with brass you only had to get it hot and it doesn't really matter how it cools.
Title: Re: Banjo Build
Post by: S. Heslop on July 28, 2015, 06:39:49 PM
(http://iforce.co.nz/i/oxxecjwz.kez.jpg)

Set up to cut the heel. Waiting for glue to dry on it before I put real clamping pressure on, but I also need to drill a few holes to accommodate the screws for mounting it to the rim. Which'll probably be easier to do while it's still flat rather than curved.

It's raised up about 2 degrees backwards tilt, and also about .5 degrees to the side so that the strings line up properly.

Also still working on the shoes. Had to cut that short since people were getting upset at the constant router noises; I was using the router table and a rotary burr to shape them. Unfortunately the way I originally intended (routing them like they were wood) didn't work since i'd sort of stuck them all to a bit of MDF with double sided tape. It was never going to be strong enough and I knew fine well, but I still wanted to try it. But i'm now just shaping them by hand with a handle screwed into the screw hole.
Title: Re: Banjo Build
Post by: S. Heslop on July 29, 2015, 07:08:47 PM
Made the shoes.

(http://iforce.co.nz/i/3xwukvtd.ftv.jpg)
Burr in the router to shape them, using a handle screwed in. I thought it was neat the way the brass shavings moved to the nodes on the table surface, like that one plate experiment thing.

(http://iforce.co.nz/i/dymzbtgs.3kz.jpg)
Other shaping was done with a file. Here i'm putting a slight concavity into the side that sits against the banjo rim, just so they don't rock about.

(http://iforce.co.nz/i/2y5clk3i.e32.jpg)
They're pretty mangled and all sorts of different dimensions. For the amount of work it took I feel I probably could've done better. But they'll still do. The shoes on two other old banjos I own are similarly misshapen, and I can only assume they were made in a similarly stupid way. If I had the time I would've tried lost was casting them

Also fit the neck to the pot.

(http://iforce.co.nz/i/yvfdm2kx.iiz.jpg)
Drilled some mounting holes. The idea is that i'll make a kind of nut that fits in the larger hole in the base, I think they call them barrel nuts. Perhaps could've done it in a more 'invisible' way but I just forgot to drill the hole before sticking the fingerboard on.

(http://iforce.co.nz/i/rsas01ud.tnr.jpg)
Sanded the heel fit. Hopefully got it close enough but it shouldn't be too difficult to adjust it. You can see the oak 'clamp brackets' in this picture; the pine ones snapped almost immediately.

(http://iforce.co.nz/i/eh35pbx0.een.jpg)
For the tension band I tried ring rolling it. It's 5mm thick 304 stainless and this piddly ring roller wasn't at all fit for the task.

(http://iforce.co.nz/i/hzdhbqrc.w40.jpg)
Plan B is to bend it around a form, since I want the curve to be fairly even but don't want to go wild trying to make a stout ring roller. That's a project in itself.

Anyways this 'form' was an offcut from making the heel sanding setup, it's 267mm and the steel after bending it to that sprung back to 365mm. I might be wrong, but i'd assume that if I worked out the percentage springback I could make another form the same percentage smaller than the final diameter and bend it to that. It's some simple damn maths but i'm not really in the mood to do any heavy thinking at the minute.

Bit disappointed about the ring roller since I was hoping to get the holes stuck in around the rim, but I wanted to know how high I should make them to fit the hooks on right, which required the tension hoop to be made. No such thing as a quick job...

Oh yeah, i'm also wondering if there's any sort of clever graphic to put on the peghead. It's not really necessary but I'd still like to stick something there. Can't think of anything that wouldn't either be boring (like my name) or get old fast.
Title: Re: Banjo Build
Post by: vtsteam on July 29, 2015, 07:52:55 PM
Those shoes look really nice!  :beer:
Title: Re: Banjo Build
Post by: S. Heslop on July 31, 2015, 04:21:10 PM
(http://iforce.co.nz/i/j4on4vrx.doh.jpg)
Welded the ring closed. Using a regular rod on stainless, I did a test first and found that it did produce a surprisingly strong but extremely brittle weld. So I butt welded the ring. But it needed some adjustment to get it to properly fit around the rim, since bending it to the form wasn't perfect. Anyways I tried bend the weld even though I should've known better.

(http://iforce.co.nz/i/togjbofg.d34.jpg)
I had a plan to drill holes and screw a joining piece of mild steel across, but I guess it's common knowledge that free-hand drilling 304 stainless isn't worth trying. I got one and a half holes in, the second hole drifted and got mangled. So I just welded the joining bit of steel on instead. It's perhaps a bit wider than it needs to be so i'm going to have to make an extra wide tailpiece to hide it.

(http://iforce.co.nz/i/45l3fqy5.y4k.jpg)
Anyways once I had the hoop on I could measure about where to put the shoes, so I drilled the holes in.

(http://iforce.co.nz/i/idy4d05k.3pw.jpg)
The hoop needed notching. I think if I ever had to do this again i'd just buy a tension hoop. They sell for about 30-40 and considering the price of the metal itself, the silver solder you'd need to do a proper joint, and the files that'll be considerably less sharp by the end of it all...

Or i'd at least buy a softer metal.

(http://iforce.co.nz/i/zk3tqviv.ymj.jpg)
Anyways after giving the hoop a brush with the wire wheel (that came on a bench grinder and I had every intention to get rid of it once i'd gotten around to buying a wheel to replace it, but i've since found it incredibly useful) I installed the rim hardware to make sure it fits.

(http://iforce.co.nz/i/zvwanua1.nnf.jpg)
All seems good. I need to rout the base of the neck to give space for the rim, but i'm going to need to fuss with router bits again for that. I'm a little scared about routing endgrain, especially with the edge banding. After that there's the tailpiece to make, and then sticking the shellac on. And unless I forgot something, then everything after that will probably count as 'setting up'. So hopefully I should have it all done by the end of THIS weekend.
Title: Re: Banjo Build
Post by: Chuck in E. TN on July 31, 2015, 05:19:37 PM
Love banjo music, and have very much enjoyed watching this build. Can't wait for the first tune you play on it! You know you have to play a song and do a video of it, fight?

Chuck
Title: Re: Banjo Build
Post by: S. Heslop on July 31, 2015, 05:59:05 PM
Love banjo music, and have very much enjoyed watching this build. Can't wait for the first tune you play on it! You know you have to play a song and do a video of it, fight?

Chuck

The worst part is that i'm probably going to also have to sing. I think i've gotten fairly okay at singing but i'm terrified to record myself just in case it's all a delusion.

Still thinking about what to play. I've got a default tune I play all the damn time and everyone is sick of hearing, so if all else fails i'll end up playing that.

What i'm most excited to see though is the statistics for the video. I've heard a few people talk about how building an instrument holds people's interest, but the moment they start playing to demonstrate it the majority of people close the video.

Title: Re: Banjo Build
Post by: Chuck in E. TN on July 31, 2015, 06:43:15 PM
Not to worry, we have watched your creativity bloom, watched your problems and how you overcame them. If you played chopstix, I'd be tickled to hear it and tickled for you!
Carry on! We're waiting, but no pressure...
Oh, don't s-pose you can play "Dueling Banjos...", sorry, being in Tennessee, I had to ask...

Chuck
Title: Re: Banjo Build
Post by: tom osselton on July 31, 2015, 06:58:11 PM
Delusion is what makes some ordinary people great!
And I wouldn't worry about the vocals I have a mute button   :D I have enjoyed following your build!
Title: Re: Banjo Build
Post by: micktoon on July 31, 2015, 07:17:07 PM
All looking good to me Simon  :bow: :thumbup: :thumbup: . Its certainly looking like a banjo now, if it sounds as good as it looks all will be well  :clap:

  Cheers Mick
Title: Re: Banjo Build
Post by: S. Heslop on July 31, 2015, 07:46:04 PM
Not to worry, we have watched your creativity bloom, watched your problems and how you overcame them. If you played chopstix, I'd be tickled to hear it and tickled for you!
Carry on! We're waiting, but no pressure...
Oh, don't s-pose you can play "Dueling Banjos...", sorry, being in Tennessee, I had to ask...

Chuck

I can play the first couple of riffs of dueling banjos but that's about it. It's funny that, despite being a classic, it's not a song you hear as much as the other classics (cripple creek, foggy mountain breakdown,). I always wonder if it's because it's gotten a reputation as being 'the banjo song' from Deliverance. It's a shame because it is a neat tune. Weird movie though, i'm still not sure what I think of it.

All looking good to me Simon  :bow: :thumbup: :thumbup: . Its certainly looking like a banjo now, if it sounds as good as it looks all will be well  :clap:

  Cheers Mick

Speaking of delusional, I think regardless of how it sounds i'm probably going to think it's great. I guess I did always feel that tone was subjective...
Title: Re: Banjo Build
Post by: SwarfnStuff on August 01, 2015, 01:21:09 AM
This has been and continues to be a very interesting build. I have enjoyed following along reading of your triumphs and mistakes - then the most interesting bit of how you got around your mistakes. Curiosity got the better of me so off to the original post. It was 22nd March so you have kept a lot of us enthralled for nigh on 5 months. Congratulations on the build so far and I am sure it will be great to see the completed job.
John B 
Title: Re: Banjo Build
Post by: vtsteam on August 01, 2015, 06:45:23 PM
Looking damn good, Simon!! :thumbup: :thumbup: :thumbup: :beer:
Title: Re: Banjo Build
Post by: S. Heslop on August 01, 2015, 08:10:12 PM
Got the frets in.

(http://iforce.co.nz/i/wmllafp2.4pd.jpg)
Was putting them in with a mallet at first but put some nice dunts into the fretboard. I've heard of a secret technique to return dents in wood by steaming it with a damp towel and an iron, so i'll give that a try. No sense doing it now though since i'll probably manage to put a few more in.

(http://iforce.co.nz/i/w51d0bzs.q1f.jpg)
I put a couple of brass dots at the 12th fret position. I was pretty pleased with how they looked. I think the 12th fret should be the only one i'll need marked, since the 5th fret is fairly obvious on a banjo, and the rest of the frets are easy to guess from their relation to the 5th and 12th. Not that I ever often play beyond the 5th.

(http://iforce.co.nz/i/l4enoirq.0je.jpg)
A brief window into my disgusting lifestyle.

(http://iforce.co.nz/i/31bzh1b0.sv1.jpg)
Where I routed to accommodate the hoop naturally routed right into the middle of one of the fret slots. If I was smart I would've measured to avoid this, but I was fussing with the ideal bridge position at the time I was slotting the frets. I'm still fussing about the ideal bridge position.

I also chipped out a bit of the edge banding, which shouldn't be hard to replace. It's something I fully expected to happen, and I was carefully approaching it on the router table to try reduce the full on sideways cutting force. But it was the moment after it chipped out that I realised I should've just cut it out with a chisel before routing the rest.

(http://iforce.co.nz/i/vfmqal0y.udl.jpg)
I also put a few gouges in the side while filing the fret ends down. I got into a bit of a hurry since my back was hurting from all the stooping over, but I wanted this done before tomorrow, so I wasn't as careful as I should've been. And of course the biggest gouges had to end up right on my lovely dots.
Title: Re: Banjo Build
Post by: S. Heslop on August 01, 2015, 08:18:20 PM
This has been and continues to be a very interesting build. I have enjoyed following along reading of your triumphs and mistakes - then the most interesting bit of how you got around your mistakes. Curiosity got the better of me so off to the original post. It was 22nd March so you have kept a lot of us enthralled for nigh on 5 months. Congratulations on the build so far and I am sure it will be great to see the completed job.
John B

Jesus. It's been longer than 5 months since I started this too. I'd like to think i'd be able to make one alot faster if I had to do it again.
Title: Re: Banjo Build
Post by: SwarfnStuff on August 02, 2015, 02:58:53 AM
Quote  " It's been longer than 5 months since I started this too. I'd like to think I'd be able to make one a lot faster if I had to do it again."
 Yeah, well you have been learning a lot, 'on the fly,' as the saying goes so now you must know a lot of what not to do. Plus you did not just make a banjo but half the machinery to do it. Have a pat on the back from me.  :thumbup: :bow: I'd offer you a beer ( :beer:) but you might put more dings in the thing, have a coffe instead.  :coffee:
John B
Title: Re: Banjo Build
Post by: AdeV on August 02, 2015, 06:02:02 AM
Dings and bumps add character... besides, when you're showing it off to people, you'll point out all the little flaws & they'll still be agog that you made your own banjo. From scratch. I certainly am, and I've made enough dings bumps & cockups on stuff I've made to be much more blas about it these days.
Title: Re: Banjo Build
Post by: mattinker on August 02, 2015, 06:20:25 AM
I'm a big fan of your threads, you have a great attitude towards making things!

You cannot not make a video of you playing your own banjo, don't feel you have to sing, but I'd love to hear what it sounds like!

Thanks again for another great thread, regards, Matthew
Title: Re: Banjo Build
Post by: S. Heslop on August 03, 2015, 06:43:15 PM
Thanks for the kind comments.

I spent the whole day from the moment I got up to now in the garage making the tailpiece. It's such a dorky little thing but it's still taking a stupid amount of time.

(http://iforce.co.nz/i/rsrtvyos.dc1.jpg)

Still not finished and all kinds of wonky. It's 'blued' by heating it up with a torch, which is probably fairly obvious in this photo with the spots overheated and underheated visible. I'm more hoping that it'll offer a bit of rust protection more than anything.

It's based off of some stupid tailpiece called the Fults tailpiece that comes up in every google search. I think it's a stupid design that claims to solve a problem that doesn't need solving (that it can't rock side to side, which a regular tailpiece can't either, and that it's 'isolated from the tension hoop' which it isn't since its holding onto the tension hooks. It's probably even worse in that regard, not that it's a problem to begin with), but it is also a very wide design that hides the funky tension band without looking too stupid.

Still need to trim the nut, which shouldn't take long. But I'll probably be able to get it stringed up and tested tomorrow, although i've got a fairly busy day till 6pm.

Don't think I said but I had a busy weekend too. I feel I would've had the thing done by now otherwise.
Title: Re: Banjo Build
Post by: Chuck in E. TN on August 03, 2015, 07:28:50 PM
Frazer, you've gotten me in a pickle! I've been wracking my brain trying to find the name of a song I wanted to suggest to you to play on the finished Banjo. I believe it was on a cassette I used to play driving to and from work when I needed to decompress (in other words, I'd had a crappy day). I can't find the cassette. I had nearly wore it out and the cassette was beginning to make a terrible squeaking noise when played. I really liked the music on that cassette, and was looking for a way to transfer the music to CD. Now, I can't find it! I can hear the tune in my head! But I can't find it online, and I can't remember the title. It was a slow tune, and I think it was from a hit movie. maybe a western... Bugger, I won't sleep much tonight with that tune in my head!

Chuck
Title: Re: Banjo Build
Post by: tom osselton on August 03, 2015, 07:38:33 PM
Do you know any of the words?
Title: Re: Banjo Build
Post by: Chuck in E. TN on August 03, 2015, 09:00:58 PM
No words, the tape was all instrumentals.

Chuck
Title: Re: Banjo Build
Post by: Swarfing on August 04, 2015, 04:51:03 AM
All I am hearing is the deer hunter music in my head now  :hammer:
Title: Re: Banjo Build
Post by: AdeV on August 04, 2015, 05:24:32 AM
Classical Gas? We had a cassette of that, don't recall any banjo tunes on it.
Title: Re: Banjo Build
Post by: S. Heslop on August 04, 2015, 02:45:59 PM
Got the strings on.

(http://iforce.co.nz/i/wgt3rbqs.02p.jpg)
Was a bit disappointed at first since it sounded especially quiet and muted. But after a bit I realised i'd just forgotten to put any tension on the head. In fact I realised that when one of the hooks fell off.

(http://iforce.co.nz/i/ve35crhd.c1x.jpg)
All seems good, aside from the crooked strings. The stupid tailpiece I made has a bit of sideways adjustment but I think this is more of a neck angle thing. I need to figure out exactly what angle to trim things to. The nut could do with remaking too since the 5th string is hard to thread through without first removing it; the hole in it is at a steep and unnecessary angle. But aside from all that it's all surprisingly good. Didn't need to adjust the truss rod, and the backwards neck angle seems about spot-on.

The neck is also fairly chunky but i'm not sure if that's a problem or just something to get used to.

Just gonna piss about with it like this for a bit. I'll probably take it apart tomorrow to make changes and stick shellac on. The tailpiece also needs finishing, and a bit of adjustment. All the strings are attached to that one screw visible in the previous post, and it's a little bit scary. I'm keeping an eye on it to make sure it's not bending or something, but really the string tension shouldn't be that strong. My big irrational fear with any banjo is that the tailpiece will somehow come loose and get launched at my face.
Title: Re: Banjo Build
Post by: awemawson on August 04, 2015, 02:59:51 PM
Simon it looks very professional.  :thumbup: Well done, it's been a long journey but I reckon that you've arrived  :clap:
Title: Re: Banjo Build
Post by: RobWilson on August 04, 2015, 03:07:56 PM
 :clap: :clap: :clap: :clap: :clap: :clap: Well done Simon , thats one hell of a fine looking instrument  :clap: :clap: :clap: :clap: :thumbup:




Rob 
Title: Re: Banjo Build
Post by: John Rudd on August 04, 2015, 03:41:14 PM
Duelling banjos from Deliverance......
Title: Re: Banjo Build
Post by: Swarfing on August 04, 2015, 05:44:23 PM
Quote
Duelling banjos from Deliverance......

That's the one I meant
Title: Re: Banjo Build
Post by: Spurry on August 04, 2015, 06:21:31 PM
This has been a most enjoyable thread to follow. Thanks for all your work involved with sharing it.
Pete
Title: Re: Banjo Build
Post by: RotarySMP on August 05, 2015, 01:32:58 PM
Cool project. Nice to see something different.
Title: Re: Banjo Build
Post by: S. Heslop on August 05, 2015, 04:12:24 PM
Thanks for the comments but it's not quite over yet!

Today I got the finish on, after sanding a bit more of a skew angle on the neck join.

(http://iforce.co.nz/i/d0mcjo1x.a30.jpg)
Took all damn day sticking it on and wet sanding it off. I put 3 'coats' of sawdust and shellac on to try fill the pores but it wasn't perfect, then I put alot of chunky coats on to try fill what remained and sanded that off, and repeated that alot.

(http://iforce.co.nz/i/3syd5mou.gnb.jpg)
The part of the neck you touch has turned out fairly well, there's a few funky pores here and there but I don't really care too much. The back of the headstock was looking great until I got a bit carried away and tried sand a slightly wet layer, the aftermath of which didn't fill too well but I could be at this crap for days. So tomorrow once it's good and hard i'm just going to go hog wild buffing it with a cloth. I've got some car polishing scubs and I'm willing to bet they'll work fine.

I was hoping to go for a satin finish since I always think gloss looks a bit tacky, but I think gloss is easier to do. At least, to get a satin i'd have to keep applying the damn stuff till all the pores are fully filled and sanded level.

But aside from that it's pretty much done. Just gotta stick it back together after it's shined which won't take long.
Title: Re: Banjo Build
Post by: S. Heslop on August 05, 2015, 07:48:35 PM
Gave it a buff with the T cut. Neck looks a bit better but there's still fairly visible pores.

(http://iforce.co.nz/i/flywebzj.ufr.jpg)

Got a good shine though, despite the pores. In all honesty I think its a bit much but I can live with it.
Title: Re: Banjo Build
Post by: tom osselton on August 06, 2015, 02:06:02 AM
I wouldn't worry for a learning curve like this a flaw is just added character.
Title: Re: Banjo Build
Post by: Swarfing on August 06, 2015, 08:14:47 AM
I think you will find that what you are calling flaws are better than a lot of peoples best. Be proud of it as I think you have done a fantastic job
Title: Re: Banjo Build
Post by: S. Heslop on August 06, 2015, 03:55:29 PM
It's done, just need to get some oil to oil the fretboard.

(http://iforce.co.nz/i/owmfpxls.djw.jpg)
Shame about the splotches. They were already on the metal, I think they looked like weld spatter. I ground them flat but I guess the metal was different enough. I was also going to make one of those... lids. Alot of older banjo tailpieces have an extra hinged bit of metal that covers most of the tailpiece and I guess hides the termination of the strings, or at least protects them from getting bumped. I thought it'd hide the mess but I think it'd just add to it!

Having the strings terminate above the pivot point was a bad idea since this tends to pull the tailpiece down.

Oh I just noticed I forgot to fully screw in the pivot pin! I'm lucky it hasn't come loose...

(http://iforce.co.nz/i/e5yqgqpz.2da.jpg)
Trying to adjust the neck didn't seem to do much but shorten it. But the gap on the right is consistent all the way up the neck, so again I can live with it~

Note the end of the fretboard. I tried routing that again to match the slightly shorter neck, but had problems and needed to carve most of it with a chisel so it's a bit lumpy.

(http://iforce.co.nz/i/u4ho4zev.apq.jpg)
I think the headstock came out quite nice. The seams in the burl don't line up properly, but the truss rod cover is canted a bit which helps hide that somewhat.

The nut probably needs doing again through. String spacing isn't great but the 5th string makes it through without any difficulty, which is nice.

(http://iforce.co.nz/i/0sqkthrs.iii.jpg)
(http://iforce.co.nz/i/pqfq2vid.ben.jpg)

(http://iforce.co.nz/i/e35inntw.wqc.jpg)
Recorded a test video, just to see how it'd go. The camera microphone isn't so great so i'll probably end up doing it next to my computer and using a better microphone.

Also it's hard to find stills that don't look weird. So here's a still of me looking very apathetic.


Anyways I know i'm mostly pointing out the bad things, and i'm not trying to beat myself up (or humble myself!). I just think they're interesting.

Now I've got to sort through over 135GB of video clips and try figure out how to best make the video.
Title: Re: Banjo Build
Post by: NormanV on August 06, 2015, 04:16:33 PM
Amazing! Just think how much easier the next one will be!
Title: Re: Banjo Build
Post by: ieezitin on August 06, 2015, 05:29:55 PM
I thoroughly enjoyed watching this thread, you have created a beautiful instrument made with care passion and great craftsmanship..I enjoyed seeing your work and tool habits and i learned things too..I also enjoyed the flaws and faults as they are apart of life and you accept them well as we all should..

Again well done sir..

Anthony.
Title: Re: Banjo Build
Post by: krv3000 on August 06, 2015, 06:04:44 PM
a fine job in deed
Title: Re: Banjo Build
Post by: AdeV on August 06, 2015, 06:06:11 PM
 :D :) :headbang: :headbang: :D :) :thumbup: :thumbup: :clap: :clap: :bow: :beer:

Really nice work!

But you didn't mention the most important bit.....


....how does it sound?
Title: Re: Banjo Build
Post by: S. Heslop on August 06, 2015, 06:27:07 PM
:D :) :headbang: :headbang: :D :) :thumbup: :thumbup: :clap: :clap: :bow: :beer:

Really nice work!

But you didn't mention the most important bit.....


....how does it sound?

I'm not great at describing sounds. Mostly because most banjos sound the same to me, and only start sounding different when directly compared. Although this one is fairly loud and doesn't sound muted or anything, so that's a plus.
Title: Re: Banjo Build
Post by: Chuck in E. TN on August 06, 2015, 07:06:09 PM
Waiting patiently for a video of you playing your creation...Still haven't found the song I was thinking about, but I can still hear it, late at night, when the house is quiet...

Chuck
Title: Re: Banjo Build
Post by: DavidA on August 07, 2015, 01:53:47 PM
May I suggest 'Don't cross the river (if you can't swim the tide)'  By America.

Dave.
Title: Re: Banjo Build
Post by: micktoon on August 07, 2015, 06:51:21 PM
Top Class Simon, you will see every little fault but not many others will it looks like you went to the banjo shop and bought a top end banjo if I did not know better.
    Real good result ,remember its the first one you have made and you have done it without having that much equiptment etc too, then the distractions of making most of what you have needed too.
  Looking forward to the video , The duelling banjo music is called something like blueberry hill I think ? There is a good video clip on youtube. The HillBilly boy is class  :thumbup:

 Top marks.......... If you want satin finish you can lightly sand with finest scotchbright type pad then wax it, leaves a not so plastic type shine on the way to satin, but test on a inside part etc first just in case.

 Cheers Mick
Title: Re: Banjo Build
Post by: vtsteam on August 07, 2015, 10:24:24 PM
Hope you don't think I'm too repetitive with praise Simon, but you just keep surprising with how great this banjo is. I can't ever match up what i read with all the negative references, and what I see when the pics arrive. I do know it was a struggle for you at times, but you seem to have won every one of them handily. Congratulations, man! :bow: :bow: :bow: :beer:
Title: Re: Banjo Build
Post by: S. Heslop on August 10, 2015, 07:50:05 PM
Hope you don't think I'm too repetitive with praise Simon, but you just keep surprising with how great this banjo is. I can't ever match up what i read with all the negative references, and what I see when the pics arrive. I do know it was a struggle for you at times, but you seem to have won every one of them handily. Congratulations, man! :bow: :bow: :bow: :beer:

Don't worry, I appreciate compliments as much as anyone!

Well it's been a few days and i've finally finished... the first draught of the script. I've got 15 pages of stuff that I felt was pretty brief (except for a couple of pages where I really lost enthusiasm). The drum sander was 5 pages, so I'm going to have to put some effort into editing this down.

I didn't spend 4 solid days on it, but i'd say it has taken me about 8 solid hours organizing and watching boring clips. For example I decided to record 6 minutes of my ass, and I watched all of it trying to remember why (I was intending to show how I have to step around the clutter in my garage, but it ended up as 6 minutes of my ass). I can't stop myself from recording loads of barely interesting garbage as if i'm short of stuff to talk about in a video.


As for what song I should play... I don't want to make a meal out of it but i've got too much time to think about it! I'm tempted to try work out a good arrangement for Baggy Trousers since it works surprisingly well on the banjo. Still a bit of a crap song without the bassline though.

If all else fails i'll just play Steve Earle Tennessee Blues since it's fairly inoffensive and easy to play. Although my singing might make it offensive.
Title: Re: Banjo Build
Post by: micktoon on August 11, 2015, 03:57:35 AM
Lol, bring it on Simon, you will be getting bookings for weddings and birthdays if you sing well   :thumbup:
  How about some bag pipes next then   :bugeye:
  I spoke to someone who played a banjo and asked about the duelling banjo song and he said he thought that was its name, I mistakenly thought that when you have the two banjos having turns each, that was itself duelling banjos and could be done with various songs ? Music has never been my best subject lol.

 Well done again
 Cheers Mick
Title: Re: Banjo Build
Post by: TD4 on August 11, 2015, 09:12:36 AM
Simon. I would just like you to know how much I have enjoyed your production, both the Banjo and your posts. Wonderful!!.   Thank you.  Malcolm.
Title: Re: Banjo Build
Post by: vtsteam on August 11, 2015, 01:39:11 PM
I have this hazy memory that the instrumental in Deliverance was between a guitar and a banjo, but definitely could be mistaken.
Title: Re: Banjo Build
Post by: awemawson on August 11, 2015, 02:12:39 PM
Correct Steve  :thumbup:
Title: Re: Banjo Build
Post by: philf on August 11, 2015, 03:06:56 PM
I have this hazy memory that the instrumental in Deliverance was between a guitar and a banjo, but definitely could be mistaken.

Enjoy:

Title: Re: Banjo Build
Post by: Chuck in E. TN on August 11, 2015, 07:52:44 PM
I have been a banjo music fan for years. The song I was referring to was on a cassette that I played so much it began to squeal so loud I couldn't stand to play it any more. Might have been an
English tape, as I spent several years in the UK with the USAF. I hoped to find a way to convert it to CD or DVD, but now I can't find it.
The particular song was a Banjo solo, I believe the song game from a major movie sound track. But it was not from Deliverance, I have several versions of that sound track. It was fairly slow in rhythm, and a real enjoyable tune. I promise, if I find it, I'll post a link to it as I'm sure folks here would enjoy it. I really like the tune, that's why I wanted to hear Mr Heslop play it. It would demonstrate the tone of his creation beautifully, in my estimation. But, as I can't remember the name, or find the tape, I'm happy with what ever he chooses to play. Sorry for the hijack.

Chuck
Title: Re: Banjo Build
Post by: AdeV on August 12, 2015, 05:33:04 AM
Baggy Trousers ... Still a bit of a crap song without the bassline though.

That sounds like a good excuse to make a Bass Banjo!  :palm: :ddb:
Title: Re: Banjo Build
Post by: dvbydt on August 12, 2015, 01:04:04 PM
Absolutely spledid build, congratulations!

Banjo picking intro on this Eagles track.



Ian
Title: Re: Banjo Build
Post by: S. Heslop on July 03, 2016, 07:28:05 PM


After almost a year I finally made the video. In all honesty it was largely those stupid title cards that put me off starting it for so long. I think they're okay on their own but it's totally not the right vibe for a video about a banjo. But for some reason I couldn't just drop them...

Anyways it wasn't so bad when I started actually working on the video. But I still feel like I could've/ should've done a better job for a video i've been sitting on for so long.
Title: Re: Banjo Build
Post by: AdeV on July 03, 2016, 08:19:06 PM
First class stuff! I had no intention of watching a 30 minute video on how to build a banjo tonight, but that's exactly what I just did - and I loved every minute of it. I wonder how much other hand-made stuff out there is dead fancy because it's hiding mistakes? ;)

Many thanks for sharing that - warts and all - and that is a lovely instrument you've ended up with. Must be nice to just sit and play it occasionally, knowing you made the whole damn thing, including some of the tools you needed too!
Title: Re: Banjo Build
Post by: Pete49 on July 04, 2016, 12:34:48 AM
great video and it sounds good. Having watched from the start the video seems quicker  :lol: Now just a small video with you playing foggy mountain. Next project a dulcimer maybe or a zither :lol:
 :beer:
Pete
Title: Re: Banjo Build
Post by: SwarfnStuff on July 04, 2016, 02:52:45 AM
Congratulations on finishing your Banjo. Only a tad over 12 months since your first post and well worth the wait. I'm sure others, like me, enjoyed watching the way you made stuff to make stuff to complete the build.
Covering mistakes? What mistakes? They are features, and let's face it, Being able to recover from our, "feature" making is what makes this hobby so fascinating.

John B
Title: Re: Banjo Build
Post by: philf on July 04, 2016, 04:01:57 AM
Simon,

Brilliant video and, as has been said already, well worth the wait.

Cheers.

Phil.
Title: Re: Banjo Build
Post by: NormanV on July 04, 2016, 04:50:17 AM
That was quite a journey. Well done.
Title: Re: Banjo Build
Post by: S. Heslop on July 04, 2016, 05:20:06 AM
Thanks for all the kind comments!

great video and it sounds good. Having watched from the start the video seems quicker  :lol: Now just a small video with you playing foggy mountain. Next project a dulcimer maybe or a zither :lol:
 :beer:
Pete

I had a longer video of me playing originally, but it was zoomed out and well... I have an awful concentration face! I recorded the new one a few days ago but i'm a bit out of practise with the banjo and fumbled almost all the songs I tried to play. Even the included clip has a couple of missed strings!

I think if I ever make another musical instrument it'll either be a resophonic guitar or a vibraphone. Or another banjo. But i've got alot of other stuff i'd like to do first.
Title: Re: Banjo Build
Post by: Meldonmech on July 21, 2016, 04:26:01 AM
A
Title: Re: Banjo Build
Post by: Meldonmech on July 21, 2016, 04:36:26 AM
A well balanced and interesting video, showing ingenuity in overcoming the problems faced due lack of ideal machinery. Not thwarted by not having all the usual materials available, you have produced an instrument to be proud of. It sounds great, welldone.

                                                             Cheers David
Title: Re: Banjo Build
Post by: Manxmodder on July 21, 2016, 05:23:55 AM
Pure genius. Hard to imagine anything that better represents the spirit of a Madmodder better than this thread.

Great video,I'm really impressed with your tenacity.  :bow: we're not worthy  :bow: we're not worthy  :)

....OZ.
Title: Re: Banjo Build
Post by: S. Heslop on July 21, 2016, 10:07:44 AM
Thanks very much!