lathe collet question

I'm happy with my 5-C collects from CDCOtools.com. I have a 1/16"-1 1/8" set by 64ths and a second one in 32nds. No problems with any of them.

Problem with 5-C collects is they don't have a large clamping range. Many guys here have instead gone with ER (extended range) collets.

Bruce
 
I assume that there would be a adaptor necessary for both the 5c & ER

tks
ed
 
ER40 collet chucks may not be thick on the ground, I waited two years before a I found one with a MT2 taper.(they weren't available) Neither were there chucks to mount on a face plate. They've started to turn up, hope you can find one. They are limited to 40 millimeters through. (one inch.) Since getting the taper mounted chuck, it's been on my lathe almost continuously.
 
Another option for purchasing or building a er40 chuck, you can purchase collet blocks hex and square and use them either the hex in your 3 jaw (my chuck is a bisson set tru) or the 4 sided in your 4 jaw chuck. You can adjust the runout to near zero. They can also be used in the mill... not an idea everyone will want, but it gets you up and using er40 collets at a low buy in number till you can get together a true chuck.

Hth
Rich
 
Tom can you please send me some info on that taper mounted chuck
tks
ed
 
Tom, I believe you meant 25mm, not 40mm for the ER40 maximum capacity
 
Tom, I believe you meant 25mm, not 40mm for the ER40 maximum capacity


Right you are, RJ, my calculator, TRS, bought in 1997 is giving me fits. 40 X .02927 gave me 1.006. WRONG.
 
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There are pros and cons for each system, that have been discussed in previous posts. I mostly use 5C similar to what Bruce mentioned, I know a few people who have purchased the CDCO 5C collet set and for the price they are very good. Unfortunately the 5C has a very limited clamping range, and even with a 1/64th set some pieces are hard to hold. Today I needed to hold some hubs with a 0.200 diameter x 0.250" long which was between two 5C collet sizes, had to go with the larger size and clamp down on the collet, and it barely held. You also get some distortion from over clamping because 5C only clamp at the tip. ER collets clamp from both sides along the length of the collet. But this is also a downside of using ER collets, they are made to clamp along the full length of the collet. Try to clamp a small piece like 1/2" in the collet and it will distort, let alone 0.250". I made my own ER40 set-tru chuck for the lathe, I use it for odd size longer stock and also it has less axial runout then my 5C chuck which is also a set-tru. You can also buy a 5C collet to ER40 chuck, but you are sometimes compounding the runout error.
https://www.ebay.com/itm/New-5C-Col...R40-Collet-chuck-holder-USA-SELL/162682518669

I mostly use 5C, it works and is quicker in my opinion then the ER40. I do a lot of repetitive turning steps, so the hubs shown below may have six different turning steps in/out of the collet and the maximum holding length is very short. Just would be very time consuming flipping wrenches out at each step with the ER chuck and you would need a spacer in the back of the ER collet so it wouldn't collapse. Wouldn't work for me because I use a through the collet stop system to set the depth. The tolerance on the hubs is 0.001". If you do go with an ER chuck for turning, I would recommend a 1/32nd collet set, the 1 mm increment sets get a bit wonkie at the clamping extremes. An ER bearing nuts helps a bit to reduce the TIR and make torquing the collets easier, but I already had one fail clamping down on a collet. Last but not least is the dismal state of the chucks available. There are generic asian direct bolt on D1-4 5C chucks and D1-4 ER40 chucks. I tried two direct mount generic 5c chucks and they had terrible TIR, like 0.006", and the ER40 chuck was also as bad, they were all returned. I currently run a Bison set-tru 5C, and previously had the Lathemaster version which was a nice chuck but seems to be no longer available. If you do get a generic 5C chuck, I would recommend a plain back, cutting the register a little bigger in the back plate and use the tap method to center it. Otherwise consider the Bison/TMX or possible Gator 5C chucks.

http://www.hobby-machinist.com/threads/what-kind-of-collet-chuck-should-i-make.59514/#post-490404
http://www.hobby-machinist.com/threads/do-i-need-a-collet-chuck.49453/page-2#post-448788
http://www.hobby-machinist.com/threads/5c-collets-good-ones-vs-bad-ones.18010/#post-442225

20171105_211808.jpg
 
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