MadModder
The Shop => Tools => Topic started by: vtsteam on April 08, 2013, 06:08:08 PM
-
Davo J got me inspired to make more tool holders. Mine aren't very sophisticated compared to his fine examples, and making 7 is not quite as ambitious as his 48, but he said to put up photos as I make them, so here goes.
So far, only blocks cut out.
(http://www.vtsteam.com/Toolholders/Toolholders1.jpg)
-
What material are you using? Looks like an Atlas 12" lathe.
-
If I made a QC toolholder, that's the style I'd make too. Drummond M style!
-
How are these indexed when you swap them out? Is there a stop for the height and angle somewhere?
-
A jack-bolt stops the height, angle is done by eye :)
-
This gotta be the simplest form of QC ive seen.. and still so damn effective..
-
Black85vette, I'm using just a piece of 1" x 2" hot rolled bar cut into 2-1/2" lengths.
And yup, that's a 12" Sears (Atlas mfg.) lathe. I don't have a QC gearbox like you do, but have the regular change gears (missing the 48 tooth, which I might just make myself).
Sparky96, Pete is right there is a screw that bears against the carriage top to set the height.
NeoTech, I'm looking forward to having more toolholders -- I only have 1 for this lathe -- which kind of defeats the "quick change" idea. I could have used a couple of them today, working on the others!
-
(http://www.vtsteam.com/Toolholders/Toolholders2.jpg)
Here is the my one QC tool holder about to face the end of a new one. I used the 4 jaw, and didn't set the block all the way in against the chuck face, since the back of the block isn't faced yet. The jaws alone are positioning the block.
To place subsequent blocks, I opened jaws 1 and 4 to release a finished piece and replace it with a new blank.
-
(http://www.vtsteam.com/Toolholders/Toolholders3.jpg)
Here are the new 7 blocks with the first machined face on each. I checked them all with a machinist square after facing to make sure they hadn't been misaligned in the 4 jaw.
-
missing the 48 tooth, which I might just make myself
Check ebay. There are lots of Atlas lathes that have been parted out. You can find about anything.
-
After facing one end I decided to face the opposite end to dimension the block. The finished toolholders are 2-1/2" long.
I don't have have a carriage stop (one more project for another day). So I decided to just place a clock indicator on the magnetic base at the end of the carriage travel.
(http://www.vtsteam.com/Toolholders/Toolholders4.jpg)
To load, this time I placed the blocks with their newly faced ends against the 4 jaw chuck face and lightly tightened jaws 1 and 4. I then tapped the block in with a soft face deadblow hammer to make sure it was seated. And then did final tightening.
I took a test cut, removed the blank and measured it with calipers to get the total amount that I needed to take off. I then reset the indicator so that it would read zero when I reached the finished dimension.
I replaced the blank and turned it down to within 10 thou of finished dimension and took it out again just to check the setup. A slight adjustment of the indicator and I replaced the blank and faced it to 3 thou over.
Unfortunately, without more QTC tool posts I couldn't do a finish cut on this face with a different lathe tool without wrecking my set-up. For the second sizing face I was using a more aggressive tool grind than on the first face and that left a rougher finish. I had to take up to 1/8" off, and with an interrupted cut, a finish bit would have been slow going.As it was I was getting about 20 thou cuts at best without chatter. I left the 3 thou over so I could finish up later.
-
(http://www.vtsteam.com/Toolholders/Toolholders5.jpg)
I managed to face 5 of the blanks before it was supper time. The two others will have to wait until tomorrow. About 2 hours work total -- which is pretty good for me. I still have to spend half my time figuring out how I'm going to do something. And this lathe is not as well equipped as my Gingery lathe. But it's coming along.
-
missing the 48 tooth, which I might just make myself
Check ebay. There are lots of Atlas lathes that have been parted out. You can find about anything.
Thanks black85vette -- I have been checking ebay last few weeks. Seems like every number of teeth comes up but 48. :coffee:
-
Is this it?
http://www.ebay.com/itm/Atlas-Craftsman-10-12-Lathe-48-Tooth-Threading-Change-Gear-/121092906859?pt=LH_DefaultDomain_0&hash=item1c31b31f6b
-
Thanks! black85vette :mmr:
-
I am not sure how I missed this thread, but subscribed now. I am enjoying this venture of yours, great pictures as well, look forward to seeing the rest.
In the first op, do you face from inside out? I do it the other way.
Dave
-
Davo, thanks for getting me going on this project! :nrocks:
I faced outwards this cut because there was a hoogie on the near edge of the blocks, this end, that the band saw left behind. Figured I'd sneak up on it!
-
Another great thing of those tool holders is that with a bit of planning/small design change you could machine both sides, use two jack-bolts opposite each other and get two for the price of one by flipping them over! All you'd have to do is make sure the thread of the jack-bolts sticks out more than the head.
-
Good idea Pete.
Another good idea is what John Hill did. He slotted his tool holder just big enough to fit a piece of HSS but at an angle. This way it gave the HSS back rake built into the holder.
Dave
-
Hi Pete
I don't quite see how that would work. Where would you put the bolt to clamp it to the round post?
I have some similar tool holders and I can make them so you can flip them over to use either end of a boring bar. I've also made some cut at an angle so I have more clearance for the tailstock.
Russell
-
I made mine several years ago and couldn't remember where I'd found the plan for them. I thought it might be an old issue of ME, but I have so many of those scattered in different boxes that I figured it would take forever to look through and find again. So I was planning to just copy the one I have.
Thinking about the possibility of cutters at both ends of the slot, but without having two jack screws or flipping the tool holder, I remembered another old series of articles in ME about a kind of sub-tool holder. this was a small block that held a lathe tool at an angle, and itself was placed in a larger tool holder, but square t that one. You set the tool at a consistent height inside the smaller toolholder block -- at least that's how I remember it. Then it was always at the correct height in the larger.
I tried to do a search for that ME issue reference, and failed, but accidentally turned up the plan to my own tool holder. Great! Now I don't have to reverse engineer something I made myself!
Here is the link -- the original article and design was by L.C. Mason in Jan 2, 1970 ME.
http://steammachine.com/hercus/page6.html
I see I did an even simpler (cruder) version of it without any of the nice reliefs -- but back then I didn't own a mill.
Now if anybody knows what issue the other unusual tool holders articles were in, I'd greatly appreciate re-reading them. I'm sure I have the mags -- just don't recall what the tool holders were called or the author's name, so I can't locate the issue.
-
(http://www.vtsteam.com/Toolholders/Toolholders6.jpg)
Faced 4 sides on 4 of the blocks and 6 sides on 3 of them by supper time.
Slow going here, mainly because of the mill scale. It dulls the HSS pretty quickly, and it takes 3 cuts for each side face. I honed the tool in the toolholder for the last cut on each face.
I used a carbide tool on the broad face to cut through the scale. Not a great finish, but at least it went a little faster.
I now remember that before starting on the first toolholder I made a few years ago, I soaked the blank overnight in a jar of vinegar and salt, and the scale was mostly gone by morning. Probably should have done that again.
-
Speaking of removing mill scale with vinegar and salt, I was just kinda wondering if the washing soda-electolysis method of removing rust and paint that I saw elsewhere on this forum would remove mill scale? Might have to try that.
-
I don't have have a carriage stop (one more project for another day).
I bought 2 of these. Because our ways are flat they clamp on to the edge very nicely;
http://www.shars.com/products/view/270/Quick_Clamp_Vise_Stop
I looked at the link you included. I like the round base that the height adjustment rides on. Wish I had seen this before I bought my QCTP. Would have suited me just fine. I really like simple and functional (and cheap)
-
[I now remember that before starting on the first toolholder I made a few years ago, I soaked the blank overnight in a jar of vinegar and salt, and the scale was mostly gone by morning. Probably should have done that again.
In the UK you can buy 'brick cleaner' from hardware shops which is dilute Hydrochloric Acid. I've used it further diluted (50%) and it shifts mill scale in 15 minutes as opposed to the hours it takes with vinegar. The scale just rinses off under the tap.
Phil.
-
There's a more sophisticated version here: http://www.lathes.co.uk/rolls-royce/ , with a description beneath the close-up photo halfway down the page. I'm not sure it was intended to be used as a QCTP. To do that, the whole assembly would have to be removed from the T slot and replaced with another complete assembly. It would be a lot of work to make a set.
A chap in NZ shows the simpler type he made for a mini-lathe on this page:
http://www.aardvark.co.nz/pjet/qctp.shtml .
I'm not sure the flange at the foot of the post was worth the swarf involved, though.
And yet another, where the "expanding post" eliminates the need for a pinch bolt, so permitting two tool slots, with a special widget beneath so two height-setting screws can
be set independently of one another:
http://mikesworkshop.weebly.com/novel-quick-change-tool-post.html
Andy
-
If you're fitting it to a top/compound slide with a T slot then the flange is necessary or the jacking screw will fall into the T slot at some angles. There isn't any need for it to be attached to the post - a thick washer is all that's needed.
Russell
-
Good point, Russell. Minilathes (and some other small Chinese hobby lathes like mine) don't have Tee slots :( so no flange is really needed for those.
If you do have Tee slots, an attached flange might have a slight advantage over a loose washer, because there would be no chance of any chips getting underneath it.
Andy.
-
Hi Pete
I don't quite see how that would work. Where would you put the bolt to clamp it to the round post?
I have some similar tool holders and I can make them so you can flip them over to use either end of a boring bar. I've also made some cut at an angle so I have more clearance for the tailstock.
Russell
Here, Russell. One small design change and you double your number of holders.
-
AndyF -- great to see a Rolls Royce lathe! Now that would be something to brag about in the workshop. :med:
I realize that I had seen the wedging toolpost on the mikesworkshop site and was very impressed. It's very tempting to do that now, since I could simply make a new toolpost -- or maybe even modify the present one.
But I hesitate to do that because I do wonder if slitting the post reduces the overall toolpost stiffness. I think I wouldn't trade convenience for stiffness in this type of post -- it is already of smaller cross section than the commercial square dovetailed QC posts, like the ones that inspired this thread.
This brings up the point I'd like to make in general that though the post design I'm using is easy to fabricate, it is not the equivalent of a toolpost like Daveo has. It is going to be somewhat less stiff because the cross section is smaller, it is less massive, and it is not as quick to change (QC) since it requires a wrench, and commercial models have a built in lever and cam action. I sure can't change out a tool as fast as Doubleboost can in his videos.
However, this design is much better than the standard lantern style toolpost which came with my lathe, so I'm very happy with it. And it's nice to have something I made myself on the machine within my machining capabilities to produce. I'm not quite up to the precision fit dovetail level yet.
I like the wedging toolpost a lot, very tempted by that, since it allows multiple tools and is very quick change. On the other hand, now that I'm making a bunch of holders, the need to have a lot of lathe tools in a single holder seems less imperative. And another advantage to simplicity I can think of -- there's less to get cut on if there aren't tools sticking out in odd directions.
-
Here, Russell. One small design change and you double your number of holders.
Thanks Pete, I understand now.
Russell
-
RussellT-- I hadn't seen the disk before, but like it a lot. Yes on mine there are positions that the jacking screw misses -- although they are rare, and I can overcome that by adjusting the compound rest to different angle if need be. But I certainly will incorporate the disk now that I see it.
One thought, however--, I think there would be a great advantage in fixing it to the post solidly -- it would increase the bearing area and stiffness of the post. In fact I'm tempted to braze them together. Having once broken a tool holder truing crankshaft journals in flat bar stock with a cutoff tool, and suffering the effects of chatter on the journal finish, I will mod anything to help improve stiffness and strength at the toolpost.
Tubal Caine (the British version) once designed something he called the Gibraltar toolpost for crankshaft turning. It was a solid mass of cast iron set on the Myford table -- I'd like to make one for myself some day.
-
Pete, Nice dwg! I had contemplated putting the tool slot at the side of the toolholder, as you show. Unfortunately, the Mason design is too narrow to do that -- the slots are too near the post bore. Since I've already cut mine out of stock on hand, I can't do it. But if someone else starts afresh and wants to, I'd recommend making the tool holders 2-1/2" square on top instead of 2" x 2-1/2", as shown by Mason.
-
Idea:
Weld a bit of rod end to one side of a tool holder blank.
Then turn that to a JT-33 taper.
-
Idea:
Weld a bit of rod end to one side of a tool holder blank.
Then turn that to a JT-33 taper.
But then you can't use it for anything else. :scratch:
How about instead of milling a slot, drill the toolholder and cut a slot and add bolts so you can clamp round bars. Then turn a JT33 taper on a bit of round stock.
Here's a picture showing some toolholders.
Russell
-
I liked the links to the Rolls and other designs but I guess the thing I like about the original post is that without a top handle it does allow a quick change. I had also wondered about the flange because I have the T slot on mine too.
The idea of two holders in a 2.5" square makes a lot of sense to me.
Russell: nice collection of tool holders. Looks like a SERIOUS wrench to go with it.
How about making one of the tool holders to take a tangential cutter instead of a tangential holder mounted in a QCTP holder? Just an idea.
-
RussellT, Nice!! I was planning on boring bar and cutoff tool "specials." And I particularly like the wrench.
re. welded on JT-33 stud (for a Jacobs chuck). I don't want to use that one for anything else. That's what makes it "Quick Change!"
-
Looks like a SERIOUS wrench to go with it.
And I particularly like the wrench.
The wrench was a bit of an afterthought. I wanted to try it so I tightened it up using a couple of short tommy bars - but it moved. I suppose I could have fastened the flange/washer to the post and keyed the washer so it wouldn't rotate in the T slot. Instead I just did it up tight. :D :D :D
Russell
-
I finally gave up on a good finish with the carbide, since even it was eroding from the mill scale. I finally just used it to scrape off the scale, ignored the deep grooves it was making, and decided to give all the blocks a final dressing with an HSS tool bit. That went better.
What a bunch of abrasive crud! Next time the scale is removed first before any machining -- thanks for the tip PhilF -- I'll look for brick cleaner. I think muriatic acid is available as such also in our local hardware store.
After the blocks were cleaned up, I placed one in the 4 jaw to center it. I marked all the blocks on one corner as a reference when placing them in the chuck. I opened only jaws 1 and 4, and the marked corner of the blocks all went against jaws 2 and 3.
The first block was centered in relation to the tailstock center, and then I replaced the center with a Jacobs chuck to start drilling for the post hole.
(http://www.vtsteam.com/Toolholders/Toolholders7.jpg)
-
Drilling the pilot hole. All pieces were drilled at each step before changing the drill bit to a larger size. The finish size of the hole was to be 1.25".
(http://www.vtsteam.com/Toolholders/Toolholders8.jpg)
-
Drilled through 3/8".
(http://www.vtsteam.com/Toolholders/Toolholders9.jpg)
-
Next drilling to 5/8".
(http://www.vtsteam.com/Toolholders/Toolholders10.jpg)
-
Keeping corners always aligned helps me remember. I really don't want to move the wrong chuck jaws or insert the blocks wrong way round.
(http://www.vtsteam.com/Toolholders/Toolholders11.jpg)
-
Last drilling operation. The largest drill I had was an odball 1-1/32". don't know where I picked that one up from! I clamped it with vice grips to keep it from turning -- they rest on the top slide (out of view). The blue marks on the chuck are at Jaws 1 and 4.
(http://www.vtsteam.com/Toolholders/Toolholders12.jpg)
-
After that was done it was time to switch to the boring bar. I took pretty healthy cuts because I was getting, well.....bored.
(http://www.vtsteam.com/Toolholders/Toolholders13.jpg)
-
Looking good, I use a texta to mark multiple things up as well.
Dave
-
Thanks Dave!
Checking the bore fit with my tool post. I put a positioning cut on the bottom of my post to fit the Atlas tee slot.
(http://www.vtsteam.com/Toolholders/Toolholders14.jpg)
-
(http://www.vtsteam.com/Toolholders/Toolholders15.jpg)
Supper time again. Top four blocks have been bored. Bottom three just drilled. Starting to look like tool holders. :ddb:
-
Nice progress. Like the bit that fits in the slot of the cross slide.
-
Looking good!
Any plans for the large pile of swarf :bugeye:
-
That's good progress. :clap: I like your organised approach.
I like the tab on the bottom of the post - there'll be no need for a big wrench. Are you still going to incorporate a flange?
Russell
-
85vette, thanks!
RussellT, thanks ......and definitely will add a skirt to the post.
awemawson, afraid the swarf just went into the dustbin. Wish there was a use for it!
You don't lose so much, and drilling and boring go a lot easier with cored out castings. Below is a pic of a few of the patterns and aluminum holders I made five years ago for the Gingery lathe. The hole has draft just like the rest of the pattern and I bored the wooden patterns on the lathe with the compound slide. The thicker holder suits a cutoff tool.
I hope to cast iron with my new furnace when the weather finally cooperates.
(http://www.vtsteam.com/Toolholders/Toolholders16.jpg)
-
(http://www.vtsteam.com/Toolholders/WeirdCenter.jpg)
Weird.
I finished up boring the last of the toolholders for the center post today. Then got ready to drill the clamp bolt hole. I marked all the block corners for the new face. Then I pulled all of the jaws out of the chuck and reversed them. Then I placed a block into the chuck and roughly located it to the area that would need to be drilled. That was off center a lot for this particular drill location and I changed the drive belt down a couple pulleys because the balance would be off a fair amount.
Then I marked up the piece in the chuck, scribed cross lines and popped it with the center punch. A put the dead center in the tailstock, moved it in from the other end of the lathe (3 foot bed) where it had been, out of the way while boring with the carriage. I was expecting to have to adjust all 4 jaws back and forth for a few minutes to line things up. I don't have a second chuck key....yet.
I slid the tailstock close and tightened it down on the ways. Then wound the center in toward the block.
Wow, I thought. Pretty close.
Still winding in.....
Wow, really close
Winding in.......
Holy cra............!!!!!!
Wound in.
Are you kidding me?????? What the...?
The center was dead on to the center pop. I mean absolutely dead on! Take a look. What are the chances of that -- with an off center location, not even marked before being placed in the jaws?? I could wind it in all the way and it just touched right on - - not the slightest side movement. Perfect alignment. Unbelievable!
(http://www.vtsteam.com/Toolholders/WeirdClose.jpg)
-
Thats really really lucky, LOL
For this type of work a pump center or spring center works great, put it on you to do list as it will be a handy accessory for off set things in the lathe for future projects.
Dave
-
Will do, Dave.
There are a couple other things I need to make before I can really finish off this project properly:
A knurling tool (I have knurls but not a holder), and a Morse taper adapter for the headstock -- it's #3, and all my useful tooling for it is #2. I don't have a collet chuck.
-
All pilot drilled.
(http://www.vtsteam.com/Toolholders/Toolholders17.jpg)
-
(http://www.vtsteam.com/Toolholders/Toolholders18.jpg)
Drilling 5/16" to 1-3/4" depth for threading. After that I drilled 3/8 to 1" for the clearance hole.
But this turned out to be a mistake. The 3/8" x 16 TPI tap wouldn't fit in the clearance hole. I measured the 3/8" drill bit and it was .372" -- the tap was .376" so no go. I had to re-drill all blocks to 25/32" to clear the tap.
-
Tapping 3/8-16.
(http://www.vtsteam.com/Toolholders/Toolholders20.jpg)
-
Clamp bolt holes all tapped.
(http://www.vtsteam.com/Toolholders/Toolholders19.jpg)
-
Slitting (with the newly cleaned up milling vice!).
(http://www.vtsteam.com/Toolholders/Toolholders21.jpg)
-
Checking the closing action with the old toolpost. Works great.
(http://www.vtsteam.com/Toolholders/Toolholders22.jpg)
-
Brave guy! I wouldn't even think of slitting that much steel. Maybe brass but not steel.
-
Well maybe fools rush in! I haven't done much slitting -- although did my older steel tool holder the same way a few years ago.
But, I was pretty cautious, took half a dozen passes at it as slow as I could crank the table, 160 rpm at the cutter on a 3" x .032 blade, used Synkool water soluble coolant sprayed on.
Didn't seem to be a problem at all. Just took my time. Pretty quiet, no heat. Was a little worried about the breakthrough at the end in case the kerf closed up, had one hand on the stop switch, but that didn't happen either. It was actually a piece of cake.
-
I suppose it depends on how much residual stress is left in the block - if it had been normalised it should be OK, but untreated cold rolled could be quite an issue.
-
It was hot rolled, faced on all sides.
-
All holders slit. It was uneventful, and though i"d taken as many as 6 passes to complete to begin with, I found that by taking it slowly, it really only required 2 passes by the last few blocks. Important to judge feed by both sound and feel. A bit of coolant was also helpful. It went well and I'm very happy with the result.
Also in the pic foreground, the stainless steel socket head cap screws arrived for the toolholders. Scored for $8 per 100. They were a better deal than the plain steel versions.
(http://www.vtsteam.com/Toolholders/Toolholders23.jpg)
-
First slitting, now slotting. First milling pass.
I decided to do this in the lathe instead of the mil to show someone without a mill how the whole process cab be done that way. Well the slitting wasn't, but could have been if you have a boring table or milling attachment. Or possibly padded the tool holders above the carriage. One other possibility would be making a jig using a horizontal section of rod the same size as the regular tool post.
As you can see the toolpost works well as a vertical milling adjustment for the tool holder. In fact I'm thinking that for very simple milling of small parts, you could make a tool holder in the shape of a milling vice that would be tightened onto the tool post.
(http://www.vtsteam.com/Toolholders/Toolholders24.jpg)
-
And the result.
(http://www.vtsteam.com/Toolholders/Toolholders25.jpg)
-
I slotted three of the new tool holders conventionally, and then I made a couple of specials today. The first one, shown below, was originally intended to take a cutoff tool.
To make it, I brazed two pieces of 1/4"steel top and bottom to allow for the extra tool thickness. As it turns out, it will also accommodate my lantern style Armstrong tool holders, including the cutoff holder.
Also shown here is a cool threading tool I haven't yet used. It has a snail shaped tool bit profiled to cut a 60 degree thread. To sharpen you just rotate it slightly and grind a new flat across the top. It's offset and raked already.
Also the cutoff tool holder -- I may just mount a cutoff tool this way instead of blade only in the QC tool holder.
Nice to still get some use out of these holders.
(http://www.vtsteam.com/Toolholders/Toolholders27.jpg)
(http://www.vtsteam.com/Toolholders/Toolholders26.jpg)
-
The second special tool holder is for boring bars. I was originally just going to bore a hole in the block to fit a 5/8" bar shank. But I realized there wasn't room in the blank to clear the center post hole. It might be beneficial to anyone else doing the Mason design to make the holders a little larger than his 2 x 2-1/2" x 1" spec.
Anyway, I decided to cut off the shank of my Armstrong style boring bar holder, and braze it to the long side of a QC holder(instead of the end). Shown below. I like this design a lot because it accommodates a wide range of bar sizes. It has two square head cap screws to hold down a vee block which is reversible. You can see the shallow groove on top for smaller bars. The underside accommodates at least a 5/8" bar.
I could still slot the end of the QC holder blank to accommodate a facing tool. But not sure how useful that would be.
(http://www.vtsteam.com/Toolholders/Toolholders28.jpg)
-
Getting a really nice collection together. I have that same thread cutting tool and it works pretty good.
-
Last drilling operation. The largest drill I had was an odball 1-1/32". don't know where I picked that one up from! I clamped it with vice grips to keep it from turning -- they rest on the top slide (out of view). The blue marks on the chuck are at Jaws 1 and 4.
Just a thought: would a hole saw be quicker approach to drilling a big hole on a lathe.
-
They have turned out great and at least you can use your old tooling in them and some of your newer gear.
Great work.
Dave
-
Looking good - excellent collection. You just need to slip them through Robs nickel plating line and they'll be ready for the display cabinet. :clap:
-
Thanks black85vette, Davo J, Anzaniste, and awemawson! :wave: :beer:
Anzaniste, I haven't tried a hole saw on something this thick before. I did do a tube sheet in my drill press that way, and it really wasn't turning slow enough. Quite a bit of screeching and smoke, despite sprays of coolant from a bottle but it got the job done. Very unpleasant though.
I suppose that it could be done better if it was run on a mill at slow speed, but I think it might take a while. You would still have to re-mount on the 4 jaw in the lathe and bore out to a close sliding fit.
On my lathe, I think a hole saw might be hard on the MT-2 taper tail stock and Jacobs chuck. But maybe I'll try it some time.
My ideal would just be to cast these in iron when I have the CI casting ability (coming up shortly). Then the hole is simply cast in. Doesn't even need a core. Still has to be bored, though.
awemawson, I agree. I'm not proud of the finish. Hoping Rob will at some point reveal all in a tutorial. I don't own a surface grinder, or a belt sander, and don't have a buffing wheel set up. My tool grinder needs both abrasive wheels. But I will work on these holders further by hand to get them more presentable when the whole set is done.
Today I have an interesting holder to make. Hope it works out. Will let you all know.....
Thanks again guys!
-
I could swear someone asked me about making a tangential tool holder earlier in the thread, but I just can't find it....
Anyway, thought I'd try it.
(http://www.vtsteam.com/Toolholders/Toolholders30.jpg)
The slot is angled 12 degrees in two directions. One side of the toolholder is beveled 12 degrees. The tool is ground at 30 degrees diagonally. I don't think I want to grind another one of those from a blank for awhile! It must have taken a half hour with constant dunking in water. And the tool is short., too. Has to be to clear the bottom of the toolholder, which must sit all the way down the post because of the tool height.
I haven't finished it yet -- need a button head screw to lock the tool into the holder.
(http://www.vtsteam.com/Toolholders/Toolholders29.jpg)
-
"awemawson, I agree. I'm not proud of the finish. Hoping Rob will at some point reveal all in a tutorial. I don't own a surface grinder, or a belt sander, and don't have a buffing wheel set up. My tool grinder needs both abrasive wheels. But I will work on these holders further by hand to get them more presentable when the whole set is done."
Hey no criticism of the finish - it's fine and certainly fit for purpose. Probably nitriding would be better anyway than nickel to give a harder surface.
-
Very neat, all of them :thumbup:
If I've counted right, there's only one out of the original seven left. News of its fate is eagerly awaited.
Andy
-
Great thread well written and love the Pics. Only comment about your Tangential holder would be that next time (If you make another) would be to not use a square blank but start with enough length to alow the tool to overhang the cross slide. Another brain spasm, It matters not (I think) whether you overhang to the side - keeps max diameter, or the front - smaller max diameter. Great work any way I look at it. Thanks for posting,
JB
-
I could swear someone asked me about making a tangential tool holder earlier in the thread, but I just can't find it....
Anyway, thought I'd try it.
That was me.
The tool looks to have a little too much rake. With the 12 degree angle of the holder I have mine set to just a few degrees, like 15. Try a couple of settings. In a holder without the additional side angle it can be hard to use for facing cuts.
Looks great and gives you some additional flexibility.
-
Funny you should say that b85V, I thought the rake seemed pretty extreme, too. But I've never owned a tangential tool holder before. I spent the day playing with it, and I'll get photos on later tonight.
It does facing cuts because it has a 12 degree angle both ways.
The source for my version geometry was here:
http://www.gadgetbuilder.com/ToolHolders.html#Tangent
But I'm beginning to think there was a mistake in the design of the sharpening jig. I believe it is giving a rake of 30 degrees from vertical instead of horizontal -- and I'm guessing that 30 deg from H was meant.
Suppertime -- back with more later.....
-
Okay, first photo, trying out a cut on some rusty hot rolled steel -- not particularly good stuff, hard to get good finish generally, but this tool bit is doing a pretty good job.
(http://www.vtsteam.com/Toolholders/Toolholders31.jpg)
-
Here's what the finish looks like close up.
(http://www.vtsteam.com/Toolholders/Toolholders32.jpg)
-
I found it would remove up to about 30 thou deep in one cut turning. Anything more broke the point of the tool. Which is a real pain because you have to grind a lot of material at this acute angle to get back to a point. Plus the tip tends to burn really easily. I now think it was too acute, in agreement with black85vette.
Facing provided a similar finish and limitation of depth of cut. It definitely wasn't a suitable tool for hogging metal off. The tool tended to jump under the cut if I tried to cut too deep as it approached the center. That would also break the itp.
-
Oh, thanks awemawson, I'll have to read up on nitriding. Is that just a commercial process, or is that something that we can do in our shops?
Thanks AndyF, I hope I can work on the last one tomorrow. :dremel:
SwarfNStuff thanks greatly! :beer:
Here's a picture of the jig I used to sharpen the tool bit. It was taken from the site referenced earlier, and the pdf drawing it referenced though I didn't pay attention to the actual dimensions other than the 30 degree angle from horizontal.
(http://www.vtsteam.com/Toolholders/Toolholders33.jpg)
-
Just now looking at the jig plan I thought I noticed a mistake. But I'm starting to think the mistake is mine.
I put a lip on the bottom of the jig assuming the tool would be sharpened pointing upwards. The lip is supposed to ride against the back of the grinder's tool rest.
But now I see in the drawing that the lip is at the other end of the jig. I thought that couldn't be right because the lip would hit the wheel between the gap with the tool holder.
But now I'm thinking maybe they meant for us to grind the tool facing downward in relation to the wheel, so they have the lip on the right side.
This might account for my too acute angle on the lathe tool ....
Here's the relevant part of the dwg.
(http://www.vtsteam.com/Toolholders/Toolholders34.png)
-
If the tool is to be ground laying downward in relation to the wheel, it would naturally have a more obtuse angle because of the arc of the wheel. It would also make sense that the wheel diameter wouldn't affect the angle -- I was wondering about that. too.
Finally, a more obtuse angle would strengthen the point, reducing the tendency to break in deep cuts. It would also mean the point didn't burn as easily when sharpening,. And it would be quicker to profile to shape originally. The jig would be easier to use -- pushing down is easier than trying to keep a short bit pushing upwards against the wheel, etc.
So, I'm pretty sure that's what was intended.
As Bugs Bunny used to say, what a maroon!
Nevermind..... :doh:
-
Last photo tonight, showing how the compound 12 deg angle is achieved. The side face of the tool holder is beveled 12 deg, and then the tool channel is let into that at 12 degrees.
The button head screw tends to roll the tool upward slightly when tightened. I'm going to add a thin washer to prevent that. I noticed one in a photo at the website previously mentioned.
The tool bit was a broken piece I happened to have. Guess I'll be making a new one tomorrow and a new sharpening jig....
(http://www.vtsteam.com/Toolholders/Toolholders35.jpg)
-
You can also slightly round the edge making the point so that it is not as sharp.
Here is the one I made to mount directly on the Atlas/Craftsman 12";
(http://farm9.staticflickr.com/8330/8399826015_e5a72d4bbe_z.jpg) (http://www.flickr.com/photos/17576549@N05/8399826015/)
IMG_5874 (http://www.flickr.com/photos/17576549@N05/8399826015/) by black85vette (http://www.flickr.com/people/17576549@N05/), on Flickr
And one I made for the 4 way tool post that will hold round stock to make an elliptical cutter:
(http://farm9.staticflickr.com/8195/8399825719_bf40d45687_z.jpg) (http://www.flickr.com/photos/17576549@N05/8399825719/)
IMG_5875 (http://www.flickr.com/photos/17576549@N05/8399825719/) by black85vette (http://www.flickr.com/people/17576549@N05/), on Flickr
-
Hi Vsteam,
Your tool pictured looks way too steep. So I went to me shed thinking I could easily find the paperwork that came with my tangential tool from Eccentricengineering.com.au here in OZ. I know the angle is stated in said paper work. Alas I must have put it away carefully (never to be seen again) :Doh:. I seem to recall a mention of 28 deg and when this is inserted in the holder with 12 deg it would come back to 16 deg. You will also grind less of your tool steel off although grinding a new piece still is a fair grinding job even with the 8mm stuff I use on my 7x lathe.
Cheers,
Swarfnstuff
-
Thanks black85vette, nice tool holders. I like the way that round one is trapped by the slide. I'm guessing there is a screw in back that pulls it in. The square one looks nice and solid and simple as well. I think I remember admiring those on CSEE. I did try radiussing the corner a little -- helped with finish, and burning the tip and well, made it easier to grind back a chip!
SwarfnStuff, thanks greatly for the actual commercial angles. To check the 12 + 12 deg compound in 3D I did a little drawing in Sketchup and the actual resulting compound angle is 16.7 degrees normal to the tool.
this gets subtracted from the grind angle to get the actual top rake. 28- 16.7 = 11.3 -- well wht do you know, the tool is practically 12, 12, 12 all around.
Making a new sharpening jig today.
-
I ended up making a new tool rest for my bench grinder. I had been using the stamped metal bracket that came with it. I didn't make a super fancy replacement capable of sharpening end mills, etc. -- that's a project for another day.
I just put together materials on hand, namely some angle iron sections of a bed frame, a spare strap hinge, and some steel cutoffs, spot welded together. But it's a hundred times better than the grinding rest that came with the machine!
Then I was able to make a new tool bit for the tangential tool holder, and I got a true 28 degrees, measured, for the cutting face.
I honed it on a little diamond hone and tried it out on the same chewey steel test bar I had earlier. It gave the smoothest finish I've been able to achieve so far -- a personal best. Probably not as good as others can achieve, but It feels shiny smooth, which is a big improvement for me. I do see some slight regular variation in surface appearance, but I'm thinking that is probably due to lathe vibration and lead screw. I need to make a more solid base for the lathe than I have right now. The whole table top shakes.
Very happy with this tool post! I might reserve it for finish use, though. I'm not sure it's suitable for taking heavy cuts.
Here's a current picture:
(http://www.vtsteam.com/Toolholders/Toolholders36.jpg)
-
The tool looks correct at that angle and the results confirm it. Depending on the metal and how secure the tool is held, I have found that I could take pretty deep cuts with mine. Your entire setup is great and would be excellent for someone starting out.
It would be cool if the tool holders were mass produced so someone could just make the post to fit their lathe and buy holders cheap if they didn't have a mill.
-
There was a chap in Australia selling them complete with a sharpening jig a few years back (maybe 7)
If I remember correctly they featured in an article in Model Engineer
-
Good job VT. :clap: :clap: :clap:
B85V. These tool holders can be made without a mill. There is also a similar commercial design - http://www.krfcompany.com/ (http://www.krfcompany.com/) but I don't think it includes a tangential tool holder. It is indexable though.
Russell
-
http://www.krfcompany.com/[/url] but I don't think it includes a tangential tool holder.
They are pretty expensive. Looks like $38 to $43 per tool holder. I can get holders for my BXA type QCTP for $9 each.
Looks like shop made is the way to go.
-
Thanks B85V and RussellT! :beer:
Started roughing out the last toolholder. I milled slots in the block and brazed in some upright pieces. Soaked the arm stock in dilute muriatic acid to get the mill scale off before working them further. But they fit in place nicely.
I'm sure you can guess what this one will be!
(http://www.vtsteam.com/Toolholders/Toolholders37.jpg)
-
Hi Vtsteam;
As for the depth of cut have a look here, http://www.eccentricengineering.com.au/index.php?option=com_content&view=article&id=22&Itemid=42 Hopefully this will take you to his demo of the 8mm tool for mini lathes. He states that the lathe used is as it came out of the box. Prices are not cheap but his stuff is good. I am way pleased with the Crobalt tool blanks.
I Agree with Black85vete that the tool grind after your new jig now look much better.
Awemawson: The company in Australia is eccentric engineering. As in the link above.
Regards.
Swarfnstuff
-
That's that's the chapie ! So my grey cells haven't all died yet :bugeye:
-
Hi SwarfnStuff thanks again for all your info. My concern re. depth of cut has more to do with the holding screw on this one. It seems to slip, and that was mentioned also re. interrupted cuts in the article I linked earlier, whose design geometry i adopted. I added a washer, and we'll see how well it does.
Thanks for replying, all! :beer:
-
All photos now restored in this thread after PhotoBucket broke the links.
-
Hi vtsteam,
Just re-read this post whilst on referee duties with my teen age grandchildren as mum and dad are at work. (Last two days of school hols.) Actually they are pretty good kids who do though enjoy niggling one another at times, hence the "referee".
:lol:
Your comment regarding tool slipping down with button head screw is actually cited as a safety thing by Eccentric Engineering. Better to have tool slip rater than break or worse, dig into and ruin the job.
Regarding interrupted cuts the same applies but in my case with my 7X it is more tool deflection with gibs adjusted as tight a I can whilst still being able to move cross slide etc. I'm thinking of removing the compound and fitting a solid riser in a way that will allow easy refit if I need the compound. I'm not sure that it is the compound or just the lack of general rigidity of my Seig clone although bolted to a lump of 12mm steel plate.
It is good to go back and re-read posts even if it was you having to do some editing due to PB issues.
Regards,
John B
-
Thanks John! :beer: I kind of forgot about this thread, and have to admit, I enjoyed re-reading it again myself even though I was trying to fix it. I forget all the stuff I did. Reading it brings back the old enjoyment and anticipation of making those tools I now just take for granted.
With lathes, rigidity is everything. That's why I started the new one, and I'm hoping to use the Rose style toolholders -- from some old ME issues. Might cast a Tubal Caine "Gibraltar" toolholder in iron, too. If I get back to iron casting again.