Hahaha.... That's almost exactly what I was thinking when I saw that claim at that price!
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4 Jaw Chuck
- Thread starter Tomc938
- Start date
Hahaha.... That's almost exactly what I was thinking when I saw that claim at that price!
I've been thinking about getting a ER32 collet chuck for my lathe as the max through size aligns with my spindle bore. $80 on AliExpress, not including a collet set. Are these things really worth it? If I got a collet set, I'd probably get a R8 chuck for the mill as well. So far, I'm not sold.
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I think they are. Although mine is a 5c, not er32. Er32 has better clamping, but I think 5c is easier to use.
I've said it before - my collet chuck lives on my lathe more than all my other chucks combined. They are so easy to use its ridiculous. I love mine.
140mower
Don
My little mill/drill came with an ER 40 collet set when I bought it, then I bought a new nut and made a chuck for my lathe..... Fortunately for me I have a complete metric transposing gear set, so that part was pretty easy. The nice part of making your own lathe chuck, it's going to be pretty true to your lathe. I use mine a lot more than I thought I would, so much more compact.
Tom Kitta
Ultra Member
Well, I am glad amazon went back to my original price. As per videos online they are very accurate. Unless you get a dud. The blue box is exactly the same as on videos and the chuck has same exact parts as on videos. So at least someone has one chuck with around stated accuracy.
Please tell me a bit more about this adventure of yours. Is your home made chuck a Morse taper? In other words, what I'm wondering most about is how you connected the collet system to your spindle? There are times when I might prefer the better clamping of an er32 over the 5C. But an MT connection to the spindle bore might negate that.
My spindle is an MT5 with a D1-5 cam lock head.
I'm not really sure how concentric my spindle MT is to the spindle axis. I'd guess it's pretty good, but I'm not sure because I have never measured it. In fact, I've never measured the outside taper either! I've only measured and optimised the system concentricity. Did you index the collet holder to the spindle somehow? Was it even necessary?
140mower
Don
My collet chuck is threaded to the spindle, the 1 1/2" 8tpi was my first internal thread cut on the lathe. Once I had the treads cut, I took off my three jaw and threaded the beginnings of my collet chuck onto the spindle and finished it out. At some point I slipped a collet over a piece of steel between centers and picked up the taper with the compound and put the taper into the chuck.
It was a pretty rewarding job and it didn't take too long. (by my glacial standards).
Nice part about doing it this way is you have a through hole, which you wouldn't with mt3...
Well done!
Yes, I forgot about the through hole part. I wasn't thinking this through.
I also forgot to think about the need for a draw bar.
All that said, I might still pursue it. I wouldn't be able to use long stock. But for collet work, I seldom do anyway. And even when I do, it's usually going to get cut-off afterward. So for those cases, it would be a bit wasteful to cut it off first and then pitch the stub. Not my preferred way of doing things. But, still worth doing I think.
And here I go again...... Making more tools for my tools......
Yes, I forgot about the through hole part. I wasn't thinking this through.
I also forgot to think about the need for a draw bar.
All that said, I might still pursue it. I wouldn't be able to use long stock. But for collet work, I seldom do anyway. And even when I do, it's usually going to get cut-off afterward. So for those cases, it would be a bit wasteful to cut it off first and then pitch the stub. Not my preferred way of doing things. But, still worth doing I think.
And here I go again...... Making more tools for my tools......
Threaded spindles present different challenges vs. camlock because there are (lathe model dependent) more degrees of freedom that have to be addressed for repeatability. The thread is primarily a retention mechanism, tightening keeps the chuck in position axially. But ideally the chuck is also 'registered' on some radial surface to mitigate looser tolerance threads factoring into concentricity. Think of a nut & bolt analogy. If the pitch diameter of the female thread is oversize relative to PD of male thread, then there is nothing guaranteeing the axis of male will coincide to axis of female even though the threads are 'engaged' & 'tight'. Axis misalignment is another way of saying 'runout'. And this (2D) misalignment is simplistic because the chuck axis could point in another direction in 3D space depending on how loose the thread tolerance is. That condition could see a lower runout reading near the chuck, but much worse runout on the part further outboard of the chuck. The only way this 'thread only' system works is with a precision thread. Which means very tight tolerances, not as forgiving to debris, wear & tear & generally more expensive. An integrated registration boss takes care of most of this stuff.
IMO if you have D1-X and considering ER collet system, use the spindle for how it's intended. You have an accurately ground external nose taper & vertical face which simultaneously register to the matching chuck surfaces. You have a cam/pin system that draws the chuck axially into these mate surfaces, so a good recipe for concentric repeatability. If you get the ER collet system with radial adjustment set screws (Bison calls it Set-Tru, Gator calls it Tru-Turn, others call it.....etc.) now you can further dial in the collet axis to the spindle axis independent of the spindle geometry. The spindle inside taper (MT5) has nothing to do with this. Well, unless you want to further enhance the system with a stop or something additionally useful.
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I know all that @PeterT . That's why I never bothered to measure the concentricity of my MT5 taper. I have a variety of chucks (purchased & fabricated) that can be dialed in as well as my 0.0001 Interapid and Mitutoyo Indicators can indicate. Some of my non-farming work requires that kind of precision.
However, the bulk of my work does not require that kind of precision. What I am thinking about here is making stuff out of old bolts and pipes and axle shafts etc, like bushings, pins, collars, holders, and all the myriad odds and sods needed to repair or fabricate parts for farm equipment - you know, +/- 4 inches or so.....
For that reason, my favorite chuck is my Bison 5C Collet chuck. That's why it lives on my lathe so much.
But as you probably know, most 5C Collets (including mine) only have 3 slits for compression. That means they often don't fit an old rusty bolt well enough to hold it solidly while I make something out of it. And that's one of the reasons why I sometimes uses shims cut from a pop can. The other reason being to protect my collets!
But I recently acquired a set of ER32 Collets with multiple slots that can hold parts much more securely. I'll probably still use shims to protect the Collets, but I'd expect to have much better overall success at turning, cutting, drilling, and other operations with an ER32 collet than with my 5C Collets.
Best of all, I don't think I need to buy a special ER32 collet chuck! The truth is that the whole idea flat out dies if I have to do that.
That is why I read @140mower's post with so much interest. His home made collet holder that connects directly to his lathe spindle made me realize that I should explore the opportunity to buy or make an ER32 collet holder with an MT5 shank on it that I can just throw into the spindle head and go. It doesn't need to be precise. It just needs to be fast, easy to use, rigid, and with reasonably strong clamping to be able to use it with the crappy stock I usually make parts from.
Does that help?
Snip
You're set up, but In the context of guys shopping for 5C collets chucks, and possibly having a MT spindle greater than 4.5, one might consider making a spindle nose adapter and draw bar for your 5C collets. They fit inside of anything 4.5 MT or greater and is a superior arrangement to a chuck. It eliminates a set off possible errors and when finished in situ run will be limited to the spindle bearing and quality of the collets. You also reduce overhang. With decent collets and bearings you should be able to get a tenth or less TIR
I had a standard Modern once with that arrangement, it was really great (pangs of regret over selling it)...and of course all watchmaker and instrument lathes have that arrangement.
Hmmmm, why 5C instead of ER32? I know I need the Drawbar either way, but one of the main reasons for going ER is the superior gripping power on imperfect stock.
Also, I have a hard time imagining what a simple MT chuck for 5C would look like. The MT arbour would need a draw bar and then another draw bar would be needed for the Collets. A double draw bar (maybe tube and bar) is getting kind of complicated.
Edit - could probably get away with just the tube.
But yes, it would have the advantages you speak of although as previously stated, I don't need the precision for the kind of work I would be doing with it.
I'm curious why you say this. I would normally associate collets to be primarily used on quite accurate stock. By that I mean low deviation to a circular section. I think ER's require more tightening torque as a function of their design & that's a function of their ability to span a larger diameter range vs 5C / other collet systems. But, at least to my understanding, I don't think collet elements in general can independently conform to irregular section shapes because they are constrained by the conical wedge surfaces which collapses them? More the opposite - I thought a good way to bugger up a collet was gripping irregular stock because all that tightening force becomes concentrated on reduced area of individual collet elements. Permanent distortion if stress exceeds yield. What am I missing here?
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Either can work, however for all the usual reasons, split collets are preferable for work holding. Why would you need a drawbar with an ER 32?
Its simplicity itself, no chuck in the usual use of the term, just an adapter. The adapter fits the morse taper and then is bored out to fit the 5C collet (4.5 was created to fit 5C's, anything smaller won't) The adapter doesn't fall out on its own, its a MT, and when machining its all held in place as its sandwiched between the collet and the spindle, i.e. collet is pulled into the adapter by the draw bar. Great on a small/medium lathe, on larger ones not so convenient...e.g. ones where you can't both ends of the spindle easily
I don't think you are missing anything. I'm just wondering about the pros and cons of doing something unconventional.
Understand that for this kind of non-precision farm repair work my usual stock is round, not square. But it's also often rusty or threaded and sometimes maybe even a tiny bit oval but not so much so that it can't be gripped by a collet. I'll typically make things out of an old axle shaft or machinery pin or an old bolt or a rod or whatever junk I happen to get my hands on.
Yes, a three or 4 jaw would be better for work holding, but I LOVE the convenience of slip it into a collet and go. Turning a piece of stock around to work on the other end is also a piece of cake and plenty good enough for that kind of work. Yes, I would expect the clamping to be a bit uneven with such imperfect stock and I would also expect the collet to get damaged if it was overtightened. I'm careful not to do that. I'll also grind away any bumps that might be more prone to damage the collet than a pit would.
Usings aluminium shims help in that regard too. But er32 also helps because it has 8 sleeves instead of just the 3 that 5C has. As you point out, er32 accommodates a broader range of shaft sizes than 5C, but I think it also helps when the stock is not ideal for that particular collet size for the same reason that it is more forgiving of size itself. I suppose I could be wrong about that. I understand you point about how the cone section works evenly on each sleeve. However, I expect the normal stress/strain relationship of steel that you allude to also play a roll here. I suppose I could model it, but I stopped enjoying exercises like that a long time ago. My 50 years of experience tells me it applies and that experience is usually right about such things. So as long as I don't exceed the yield strength of the collet steel (even in a small location) I am reasonably confident that I won't be damaging them. Again, an aluminium shim helps there too.
I assumed that a Drawbar would be desirable to provide positive retaining of the MT5 adapter and to facilitate its removal with a sharp rap with a wooden or rubber mallet.
It's the 5C version that is a little fuzzy for me. I've never actually seen a 5C collet holder that doesn't draw the collet into the holder via the external threads at the rear of the collet. But I have no reason to believe that a long tubular draw bar (or at least one with a tubular end on it) couldn't serve that function. I've just never seen it. I do have a 5C Indexable Holder that uses a rear crack for this purpose though and one might think of that as a short draw bar.
Similarly, I've never actually seen an MT5 Arbour for 5C Collets and I wonder how that would work too. How do you access the rear of the collet to tighten it? At the same time I worry a bit about a way to make sure that an MT5 arbour doesn't slip or that it might get stuck. A Drawbar would potentially address both both problems.
On the case of the ER32 / MT5, the only reason for a Drawbar would be to retain the MT5 shank and to provide a way to release it by bumping it from the backside with a rubber or wooden mallet. The er32 itself uses a collar to tighten it in place.
Thanks, I think that helps answer my question. The draw bar attaches to the rear external threads of the 5C (as speculated above) and in so doing, that Drawbar also retains the sandwiched MT5 adapter. But I'm not sure how you get a stuck MT5 adapter out with that arrangement unless the Drawbar has a second shoulder for the backside of the adapter. It would help if I could actually see one.
My lathe has plenty of access to the back of the spindle - no issues there.
Sorry I was drafting the previous reply when you posted this.
Thank you! The photo is PERFECT! It confirms what I suspected.
I still think an er32 would be better though. The adapter could be tightened once with its own Drawbar, and the collet tightened with a collet wrench, and the er32 providing superior gripping force.
On the other hand, that 5C design would facilitate longer stock......
Same as a lathe centre, tap it out with a rod with a brass or AL pad on the end. Ideally the brass or AL pad is close to the diameter of the adapter small end and it comes out easily (collet is already removed of course and drawbar withdrawn)
I can't believe how organized I am that I can find these photos lol - you've sent me on a nice trip down memory lane
. 2008, some kids off at university, some still being run around for hockey practice. Thats a SM with a D1-3 camlock and MT 4.5 taper
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Same as a lathe centre, tap it out with a rod with a brass or AL pad on the end. Ideally the brass or AL pad is close to the diameter of the adapter small end and it comes out easily (collet is already removed of course and drawbar withdrawn)
I can't believe how organized I am that I can find these photos lol - you've sent me on a nice trip down memory lane
View attachment 18122
Perfect again!
I suspect one could attach a brass ring to the Drawbar such that once the collet is removed, and another slotted collar removed at the back spindle end, the Drawbar itself could act as the tool to remove the MT5 taper.
Of course, with an MT5 ER32 tool holder, none of that is required. The Drawbar itself without modification can both retain and remove the MT5 Adapter.
I am definitely not so organized as you. But I can certainly appreciate the memory lane effect. It happens to me every so often too.
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chip4charlie
Well-Known Member
Just got mine from LMS. It also says 3000 rpm max and "K72-125", and branded as a Sanou. Checked Amazon first but none in stock. Got it with the conversion plate for my Vevor 7 x 12.
Stefan reviewed a six-jaw Sanou chuck and found it pretty decent for the money: