DIY fixed steady for a lathe: CQ9325 10 x 18" (250x450mm)

[PekkaNF]

It all started out of spotting drill...that is a slow progress.

So, I need a fixed steady to make the spotting drill. MEW #173 has an Harold Hall article about fixed and traveling steady. I'll borow there few tricks. Now when I'm confident I have a correct procedure, I'll make one of probably many fixed steadies. Doodled a sketch on the paper, mainly based on the lathe dimenssions and materials I had in hand.

But first I need keys for a rotary table. This is probably a third time I use it and now I need it stay put. The original keys are closer to 16 mm wide and slots on my mill are 14 mm.

I used pop-rivet drills (I like short drills) and one day I found a new type of el-cheapo drill "Piraha" or something from a shop. That looks like a counterbore to me, I'll try it here. First I made a little a under size hole for a "counter bore pilot", then I used this ugly drill to make a counterbore and then I opened the pilot hole final size.

Pekka

Looks like this:

[PekkaNF]

Back to the fixed steady. I have a double v bed on the lathe. I figured I should make the front v-guide locating one and put plenty of play on the rear v-guide. I slit bottom of the V-grove. Makes milling of the Vs easier.

Then I set the piece on 45 decree angle on the  milling vice and made v:s with normal D20mm end mill. One flank at the time. Nothing special about it. Few tries and some measurement.

Somehow lost the pictures when I milled Vs. Bummer. I'm sure someone more proficient would have deviced better way: This what came to my mind first, when I looked my mills.

[PekkaNF]

Riser or whatever that stativ is should have been made of least 12 mm thick iron metal. I only had some 30*100mm ali. I even went to skip diving and to a local recycle station, but no such a luck. Aluminium has to do, although I don't like it.

Little milling with 24 mm slot drill, tidying up and aligned the parts with one bolt. Then I drilled/counterbore/thread parts for allen bolts.

Then thin chuck is one special: MT3 B18 or B16 arbor modified to accept Bosch wood router 6 mm and 8 mm collet/nut. Rigid enough and the nut is small - goes close enough most of the time. Here I used it to hold a slot drill. I need a flat on the bottom of v-guide. I placed a bolt here hoping it won't interfere with anything. Counterbore here at  "clearance" cutout does not hinder indexing. It would have been hard to start the hole accurately without this flat.

Pekka

[PekkaNF]

Today I marked the centre of the fixed steady on the lathe. This idea is from the Harold hall. I think it is really clever: You mount drill to a three jaw chuck and advance the fixed steady blank towards the drill with tail stock. Should make the hole close enough the rotational axis, I cranked traverse to keep the fixed steady upright and square.

Next step is to center it to the rotab. As luck would have it, I had a 6 mm hole on the blank and therefore I could use 6 mm drill rod on the MT2 collet mounted on the rotab.

Needs over 6 mm rise to clear the collet nose. I had some 8 mm key stock at hand. Anyway, it would have been slightly embarasing to mill groove trough the blank and on the rotab.

[PekkaNF]

Circular "deep" hole milling manually

I had to mill central hole manually just to see if it is a PITA claimed to be. I can conform it is - least with this piece. Does anybody knows how to make it less painful experience.

This is 30mm deep, 60mm dia, I could not see using a boring head or anything else I had on my inventory. Is this rotabroach territory?

I used 10 mm long end mill and it was not a very sweet experience. I probably should have resorted to a slot drill, but I didn't have any appropriate size. My milling machine really does not have any good high speeds. I used IPA (Iso propyl alcohol, ethanol, detergent water mix as a coolant - original use of this cocktail it is to keep wind shield clear of ice in the winter). Should have used compressed air and shopvack. Had to use hook to dig the moss out of the groove. How on earth aluminium swarf can pack so tight?

Also on the last two round I had to undo one of the clamps at a time to clear the collet chuck. More reasons to get few 16 mm endmills/slot drills.

Last round was nerve wrecking I hang on the coupling lever for my dear life for the last few degrees and disconnected the drive at the first hint. I was halfway expecting it to snatch and turn it to big mangled piece of aluminium. But it went rather nice. Core just moved something like 5 decrees and there was a shalow mark on the periphery of the steady, but nothing to warrant a clean up run.

Finally got it done. Took an hour and some 10 mins to clean the milling machine after the excercise.

This is for today.

Tommorow I'll fight the arms and their groves. I don't have eactly the right material.

Pekka

[PekkaNF]

Let the show begin

I have tried to read the da-rulez and I figured I had invite critique?
http://madmodder.net/index.php?topic=2527.0
"Also bear in mind, if you ask for comments or critiques... you may not like what you hear. But thats also what this board is about... without constructive criticism, someone may not finish a project or worse yet, get hurt."

I don't have a very thick skin, but luckily I don't understand all the fines either. And please bear with me: I have dyslexia on all languages, I read fast and understand most of it, it's mostly writing: I'll put letters slightly on wrong order or use "close" letters and I even don't see it. My speciality is to "skip" few important letters every now and then...I'm trying speller, but it gives me ridiculous suggestions - normally opposite I want.

Anyway everyone have to start somewhere if someone sees that I'm making something completely wrong I'm happy to be corrected.

The trouble I had was manual circular milling - first time I ever tried but there is probably a better way of doing it. In the bright side:
* It workked, although it was slow, but it was a deep hole and I could not run mill fast enough
* End mill stayed shar and it was very cool (immersed on coolant all the time)

then again:
* Should I have used an slotdrill? I used four flute end mill that has a limited plunge ability. I used very gentle ramp down (slow Z with left hand, while winding willies out of rotab w/right hand.
* Probably should have gone bigger and produced more swarf, this "deep", would have improved D/x
* feeds are hard to handle well manually, on the other hand I felt all the time how the cutter was cutting
* Made a bad choice with coolant - heard it used, I had to have a try. Next time I'll rig shopvack with narow spout

Maybe I should have tried something completely different? I could not see myself using holesaw, I don't thik chips would have come up and I dont like to peck drill on kneemill without pinole. On bright side: I would look soon like govenor of California when he was young.

But that was yesterday. Today I have to consider arms.

If I understgand right arms:
* better be softer than piece to be turned
* Should not easily weld on that piece - this would exclude most aluminiums

I have 10*10mm square brass rod and then probably a bronze plate that is 8-9 mm thick....from junk-yard (alhough they don't call it that anymore they all are recylcle something). Both feel smallish, I'll probably lash up someting temporary and fix ita lter when I'll get something better. Now How do I keep witnesmarks when I take it off the rotab?

Anything I should know about the arms. Most builders don't go into very many details here on materials and shapes. V-on the end and everyting reasonable square? That's it?

THank you,
Pekka

[AndreasL]

 

Very nice I must say.

Keep us updated about your progress.

[PekkaNF]

Thanks. Hey, I was looking for a advice...typical Finn.

Anyway, didn't had a change to do much on this one.

I have mixed feelings about the arm materials:

1) I have 10*10mm brass rod, but that is probably way too small, unless I made 4 mm slot for M4 retaining screws....
2) Second choice is mystery bronze/brass, probably I could make 8*15 mm arms, where I could use M5 retaining screws...

Any toughts? Should I just put some OD25 mm tempering steel rod on the lathe chuck and spin it 750 rpm and advance a piece of both materials on the lathe tool holder towards rotating piece and see which fails first?

Thanks,
Pekka

[Henning]

Since you asked for advise...

I'd say some sort of brass would be good for the arms as you call them. I do suggest you take a good long look at incorporating ball bearings though.
Have a look here to see what i mean: http://littlemachineshop.com/products/product_view.php?ProductID=2419&category=1

Actually, thinking it through, most arms are probably bronze of some sort...

[PekkaNF]

Thanks. I'm not a big fan of inrunning nips - they tend to draw in all sorts of debris that is produced on the lathe. I have some cam rollers, I probably could use them if I had to.

I'll be using this on steel first, I think I'll aim to it and if it comes to softer metals I'' try first nippin brass shim or something between arms and a rotating member.

I have been toying with an idea of using a large deep grrove ballbearing and a spider or sort of pot chuck instead of arms on a fixed steady...I'm ALMOST convinced that it could work with softer materials and if done with extreme precision. I'm not there yet.

Still drawing right size of arms - that is a bad sign: If I dwell on something too long, it usually fails first time. I'm jinxed!

Pekka

[andyf]

Pekka, perhaps you could use steel arms with brass tips brazed/silver soldered on the ends.

Andy

[PekkaNF]

Pekka, perhaps you could use steel arms with brass tips brazed/silver soldered on the ends.

Andy

With my brazing skills? Umh. Looks like every brit is born to braze and born with a blow torch. Even idea of it gives me heebie jeebies -shudder-. I did consider doing arms out of key stock (softis steel) and screwing brass tips.

Lets's see how I feel on wednesday - my mext chance.

Pekka

[John Hill]

Very interesting project Pekka.

[PekkaNF]

Pekka, perhaps you could use steel arms with brass tips brazed/silver soldered on the ends.
Andy

TAKE II: Maybe I should give it a try?

I found out of treasure pile one roller bearing eh? retainer? 23 cm. diar ring that seemed to have right kind of bronze.

I have silver soldered copper pipe with bronze lookking brazing rods and a mysteryflux I got from shop. I have a sievert LPG torch.

Would this kit work?

But I don't have a foggies idea and after searching this site I'm even more confused? I can find stuf like this:
http://www.lucasmilhaupt.com/en-US/brazingfundamentals/
It's great, but very long way to my spesific need: Bronze on steel key stock with siervert torch.

Torch: I have a standard sievert and Rothenberger ROFIRE
http://www.rothenberger.com/en/products/product-groups/soldering-and-welding-equipment/soft-soldering-unit-rofire.html
I have 11 kg LPG gas for Sievert and Multigas 300 Propan / Butan for Rothenberger, but I can get MAPP or Maxigas 400

1) I understand cleaning and fitting the parts together...Do I need to picle the parts? If I do how and what?

2) Do I need a special solder and flux? I have some mystery stuff I have bought 20 - 11 years ago. See picture. This sort of stuf I can get from any plumming shop. I can get also Rothenberger brand fluxes and brazing rods from local Bauhaus, but most of the British brands I see advertised on magazines are not available here. Im I lookking for a silver solder and flux for that temperature or is it more complicated?
http://www.rothenberger.com.au/upload/rothen_rothenberger/promotion/161/public_document/Watermark%20Certificate.pdf

3) How to fix? Mill the slots, clean, piece of solder between the joints, bronze part up up and heated, fluxing, slow cooling?

Do I have a good chance for success this way or should I just trundle away with smallish arms (cut from 8mm thick bronze?)

I know I'm asking a lot, but I know so litle about brazing, I need close to blow-by-blow intructable with this equipment, materials and aplication, othervise I even can't learn from my mistakes.

Thank you,
Pekka

[John Hill]

Hi Pekka

Silver soldering is easy!

Just clean your parts with a file, no need for any chemical treatments.  If your flux is a powder then mix a little into a paste with water, apply flux to the parts, not too much but make sure the surface is covered with paste where you want the solder to be but avoid putting flux where you do not want the solder.

Place the pieces in position in a little hearth that you make with fire proof bricks. It is important that the heat is all around the work and a little hearth does that. Snip off some pieces of the solder and lay them along the joins.

Heat the work, heat both pieces trying not to play the flame over the solder, in fact it is best to heat from the other side if possible.  If you have a big piece it is best to start heating it away from the join so that when you heat the join not so much heat will flow away.  When the metal is hot enough the solder will melt and flow into the join by osmosis so the joints should be close fitting but they do not need to the clamped or anything like that.

If you think there is not enough solder to fill the join you can add more, do this by dipping the end of the solder stick into your flux paste and melting the end over the join.  This is OK but you will have a much neater job if you can avoid adding solder in this way.

Once the solder flows into the joint stop heating then let it cool naturally in the hearth.

John Bogstandard is a expert on this and will hopefully add his advice.

John
(aka The Artful Bodger)

[andyf]

Hi Pekka,

The rods in the long tube look mechanically stronger (50 daN / mm²) than those on the left (38 daN) but it looks like those on the left don't need as much heat.

I'm not sure about the flux in the blue container, because there is no temperature range showing, but the flux in the white container looks like it might be OK.

But if the Rothenberger rods and fluxes are made to match one another, it might be better to rely on those.


As to actually doing it, there are folk on here much more experienced than me, and you would be better taking advice from them. As a novice, I have done some silver soldering (brass to brass and steel to steel), and it all turned out OK. Some was even done with a small butane/propane torch like the one shown on the blue container, which didn't really deliver enough heat, and which took far too long though it did work in the end.

Search Madmodder for "silver soldering" and you will find demonstrations like this http://madmodder.net/index.php?topic=4958.msg55323#msg55323

Andy

 

[PekkaNF]

Thank you all.

A lot of my brazing stuf is a "souvenir". The rods on the picture are from Paris, went there for a few days with my newly wed wife. Had to find a hardwarestore and found those. White flux was sold to me to braze copper pipes with phosphoros bronze and it is liquid. Paste is probably from Holland, that is even oder...I don't remember seeing temperature rating.

OK, I think I have eneough to give it a try. Just few more questions:

* Do I fabricate the parts ready before brazing or do I just cut arms (shoes) and tips to rough size and finnish after soldering? I'm most likely using a key stock, brazind does very little to properties.

* Does part relative position matter? Using a heart (I have some firebricks and an "insulator" palte) I think I could prepare tha parts as instructed before, stand them up (bronze tips up) with some mild steel wire and heat them up as a lot. Although this probably would heat the tips easier than the arms. If I put the smal tips down, arms are easier to heat, but tips will be touching insulator....

Thank you very much,
Pekka

[John Hill]

Pekka

If it was me I would roughly form the parts and finish them after brazing, the pieces may move a little and if you do the finishing after that is a chance to correct things.

It might be best if you can lift the pieces, especially the biggest pieces, clear of the bricks.  Maybe you can lay them on nails or some scraps of steel,  this will allow the heat of the flame to go under the work as remember you have to heat it right through for the solder to flow throughout the joint.

I had another look at your posts and I think the challenge you will have will be to get the pieces hot enough.  It might be quite difficult with that little torch but if you build your hearth like a little cave you might be able to do it.  Good luck!

[andyf]

Hi Pekka,

If you stand the arms upright with the tips on top, it will be difficult to get the solder to flow into the joint. This isn't like soft soldering, where you get the job hot and then touch it with the solder. If you can lie the job flat with flux applied in and on top of the joint, put a piece of solder on top of the joint and then apply the heat from below, the solder should liquify and then flow into the joint with capilliary action aided by gravity.

Like John, I think it would be a good idea to roughly form the parts and finish them after soldering/brazing. The force of the gas jet might blow a small piece of bronze out of position, so the easiest way might be to cut each steel arm roughly to length and solder/braze a long piece of bronze to it, then cut the tip off to the correct length afterwards. This would help in positioning the parts, but bronze is a good conductor of heat so you might not be able to get a long piece hot enough.

Andy

[AdeV]

Going back a few days....

Circular "deep" hole milling manually

I had to mill central hole manually just to see if it is a PITA claimed to be. I can conform it is - least with this piece. Does anybody knows how to make it less painful experience.

The only thing I'd do differently to the way you've done it; I'd have used a roughing cutter, rather than a smooth endmill/slot drill (speaking of which - there's no significant difference between the two, when cutting "on edge" like you are. I suppose in theory the 4-flute endmill would need a slower feed than the 2-flute slot drill, to prevent clogging, and the former would give you a nicer finish.

A roughing mill, on the other hand, has serrated edges, which allow you to chew through the metal much faster than with a regular end mill (using a 12 or 16mm roughing cutter, I'd be taking 1/2" deep cuts in Ali, at whatever feed rate "felt right". Obviously, you have to cut the hole undersize, and finish off with a proper end mill (or slot drill, if you run it fast enough), to leave a smooth edge.

Have a look on eBay for roughing cutters; or drop me a line if you fancy a couple of 12-16mm ones, I have a few spares.

[PekkaNF]

First thing first: Thank you fellas, I tried silver soldering and I'm pretty sure I had an success. Remote controlled brazing - wring commands

First picture: Parts before cleaning. Dish soap, hot watter, steam blast from espressomachine - well I had to make one latte! Then filing, brake cleaner (not the one with war quality chemicals) and some 1/2 hrs od drying out.g

Second picture is about torches. I used the Sievert and the burner that is connected to it. Took only less than 10 secs to bring whole lot to a dull red.

Third is heart. There is small cap back/up to allow good circulation. I had flux prepared on arms and placed there snips of silver solder.

Fourth is about brazed parts. I used M8 nuts and M3 screw and washers to hold parts evenly. I was not sure when solder melted...first flux pubbled and then solder flashed, I held heat a little longer and pressed the brass bar down. Could have used just tad more solder on one joint.

Fifth, sawn off and evened out on the mill. I wonder if there is any good way of cleaning the residue? I used brass wire brush.

Pekka

[lordedmond]

get some citric acid powder form your health food store or home brewing store

mix about two tea spoons to  500mm of water  dunk them in for a couple of hours that should do it



don't worry its very safe its only lemon juice you can put your finger in no trouble ( unless you have a cut then it stings )

Stuart

[PekkaNF]

Going back a few days....

The only thing I'd do differently to the way you've done it; I'd have used a roughing cutter, rather than a smooth endmill/slot drill (speaking of which - there's no significant difference between the two, when cutting "on edge" like you are. I suppose in theory the 4-flute endmill would need a slower feed than the 2-flute slot drill, to prevent clogging, and the former would give you a nicer finish.

A roughing mill, on the other hand, has serrated edges, which allow you to chew through the metal much faster than with a regular end mill (using a 12 or 16mm roughing cutter, I'd be taking 1/2" deep cuts in Ali, at whatever feed rate "felt right". Obviously, you have to cut the hole undersize, and finish off with a proper end mill (or slot drill, if you run it fast enough), to leave a smooth edge.

Have a look on eBay for roughing cutters; or drop me a line if you fancy a couple of 12-16mm ones, I have a few spares.

Thank you

Right now I'm thinking which cutters to buy. Looks like I'm missing a long roughing mill for ali I used long 10 mm for this. I also two 14 mm mills, just trying to figure out if this warrants 14 mm ortlieb collet, then 14 mm would be pretty logical. I think I buy 16 mm short slot drill and short end mill.

I opened 3 mm deep slots for arms (shoes), with 12 mm short roughing mill. Removed ali pretty fast. I made slots with three passes to keep them strainght. Made slots pretty tight. I'll see do I need to file anything after I cut the lots to the arms.

Pekka

[PekkaNF]

get some citric acid powder form your health food store or home brewing store
mix about two tea spoons to  500mm of water  dunk them in for a couple of hours that should do it
don't worry its very safe its only lemon juice you can put your finger in no trouble ( unless you have a cut then it stings )

Stuart

Thanks. I'll try it right away. I always have some!

Pekka

[andyf]

  Finns can silver solder!

Slotting the ends of the steel arms, standing them on end, laying the bronze across the slots and doing all three at once like that was a great idea, Pekka  

I'm glad it went so well. I'm sure you will have enough solder in the third one, but just to be sure you could fit it at the bottom of the finished rest. In use on the lathe, the job being turned will tend to flex upwards and to the back of the lathe, so the bottom arm won't be under much pressure.

Lemon juice contains about 48 grammes of citric acid per litre, which is about as strong as Stuart's mixture, so if you can't find citric acid you could always use that. But I think alcohol prices in Finland are high, so I expect there will be plenty of home brewing and wine making shops  

Andy