Collets vs 3 jaw chuck

bryan

bryan

Bryan Armatys
When working with round stock, say, .200 to .700 in diameter would collets be a better way to hold the material than a 3 jaw chuck? I'm working with a 7x14 lathe that seems to be very accurate.
The headstock is 3mt taper, and I have found collet chucks to fit, and kits that include numerous collets, but they are ER16 or ER32 or ERxx. What is the difference in ER?? collets?
Thanks
Bryan
 
Brian,

The various series of collets are different shapes, sizes and types. Each will have a range of material sizes they work with. Some are for in chucks, some for in toolholders, etc. Some toolholders go in chucks and then use a collet. I think that for in lathes such as most of the people here use for gunsmith work, an (Whoops, meant 5C, thanks butch. I said R8) collet would be the most common. These would be common for use on things like a grinder and other machine tools around the shop.

Collets are real nice for working to tighter tolerances without the need to indicate parts like in a scroll chuck or 4 jaw. They're usually pretty close and , if the setup is good, they repeat well enough to do a lot of jobs accurately, and real quick. For instance, the Victor lathe I use collets in, has a handle like most others where a quick pull on the handle will open and close the collet. It's not a big deal to remove the chuck and set it up and it's super fast for changing parts.

I'd say though, that they are more in line with production work, than for serious metalworking. if you do a lot of chucking and re-chucking for short operations, by all means get them. If you do general gunsmithing for yourself as a hobby, they are a luxury that will not get a lot of use.

Whoops... forgot... ER series collets I believe are for in toolholders. These most likely would not be used in a lathe. Someone else here may correct me on that. I think these are more for toolholders in Mills and the like. An "emergency collet" is a soft material that you can machine and modify for your own purpose. I've never seen an ER Emergency collet tho. There are a lot of ER series, just fyi.
 
Last edited by a moderator:
The ER collet is a European standard (DIN), and yes, they are used as a round shank tool holder.

They have a little more holding power than the R8, but I do not care for them, because they are more of a pain to change the tool.

I would go with an R8 or 5C for your shop equipment, unless you have a european machine, and would have to respindle it.
 
Last edited:
I don't believe that I have seen R8 collets in a lathe. They won't accept a long piece of material as they are internally threaded. The most common is 5C.
Butch
 
Another type of collet is the Jacobs Flex Collet Chuck and Collets which looks smiler to the ER collets but work with a lathe and are pretty easy to use.
 
Butch Lambert said:
I don't believe that I have seen R8 collets in a lathe. They won't accept a long piece of material as they are internally threaded. The most common is 5C.
Butch
Click to expand...

When I said shop equipment, I meant R8 for a milling machine, and 5C/3C for a lathe, I should have been more clear.
 
Just a little clarification.......

*R8 collets are used in the spindle of a milling machine for tool holding.

*5C collets fit the #5 Morse taper in the lathe spindle bore, as well as various other work holding devices.

*Your #3 Morse taper spindle will not take 5C collets....it is too small. You would need some sort of collet puller to use a collet system anyway.

*If you aren't doing production work, collets aren't an advantage. The most accurate way to work is to cut the most critical features as your 1st operation, then cut the part from the bar that is held in the 3-jaw. (If the whole part is toleranced the same, do the "busiest" end first.) If the 2nd side of the part is more critical than you can manage in the 3-jaw, put it in a 4-jaw (or collet....but don't count on a collet being automatically "perfect").

-Dave-:)
 
I can vouch for that Dave. I had a few Enco Collets and I replaced them promptly. I usually use the 3 or 6 jaw and after the first operation, I part it off.
Butch
 
Bryan,The ER 16 & 32 colletts that you ask about are Precision colletts that have a .040 operating range. The collett holders come in different tapers & also straight shank for use in Lathe chucks,They are very accurite & great for small work holding,But a pain in the butt to use.High end collett chucks are far superior for very precision work. I have a Harrision AA lathe,13/25 That is setup with a Pratt & Burnered Multi chuck & Colletts,I can turn that chuck up to 2500 rpms for small work with .repeatable results,Barrel work is not the only part of a working Tool ,Gun Shop.Thin wall tubing will spin out of a 3 jaw chuck,but not a good 5c collett. 3,4 & 6 jaw chucks are all needed for various operations,but a good collett is worth having in your shop,it will earn its keep. BILL
 
Butch Lambert said:
I don't believe that I have seen R8 collets in a lathe. They won't accept a long piece of material as they are internally threaded. The most common is 5C.
Butch
Click to expand...

Sorry for the mis-statement. Thanks Butch. Yes, the 5C is what I was thinking but had R8 on the Mind... You are correct.
 
bryan said:
. What is the difference in ER?? collets?
Thanks
Bryan
Click to expand...

ER collets were developed by Erickson Took Co. Erickson was bought out by Kennametal in the 80's or 90's. Now several tool holder makers make the ER collets. One thing thing that distinguished Erickson from Cushman, Ballis, etc was that the Erickson had a double angle on its designs. This gave the Erickson clamping motion on both ends.

ER8, ER16, ER32, etc. are size ranges or "families" of collets. The Erickson TG series were the heaviest duty and they were double angle collets also.

The Erickson patient ran out some time ago. The principal makers of the Erickson collets are Kennametal and T.M. Smith Tool Co.
http://www.tmsmith.com/products/groups/collets/index.asp
 
Last edited:
The G4003G does not have threading in the outboard spindle bore. How could I adapt to
use 5C collets?
 
It depends on the taper of the ID of your spindle. Most that I have seen have a tapered adapter that fits the spindle and your collet fits in the adaptor. The threads on the collet fit into the drawbar part of the collet closer.
Butch
 
Lilguy,You can buy a Manual Collet chuck for your Lathe,It uses a Key instead of a Drawbar,Enco has a good selection of chucks & the adapter plate that secures it to your lathe headstock.I am not familiar with the Grizzly Lathes,so i can not tell you whar mounting plate to buy,but there are members on this site that have a lathe ,such as yours that can tell you what you need. I prefer the manual collet chucks over the Drawbar style ,because you can run higher RPMs & not worry about the bearings in the drawbar going south from high RPMs.My P&B Collet chuck is a Manual & uses a key like a 3 jaw chuck does. BILL
 
Collets

From a machinist standpoint, collets are a neat addition to your tooling if you are doing a lot of small round pieces that are fully machined, then parted off. You can also get Hex ID collets. They are especially good for what we used to call production work, (CNC has just about replaced the manual production lathe).
But trust me, you can sure live without them. If it came down to buying a good Buck Chuck, (3 or 6 jaw), as opposed to a collet assy, I would take the chuck in a minute..........jackie
 
To me that looks like it would be a usefull addition. For my lathe I have a 3 jaw adjust-tru, 4 jaw independent, and a 5C collet attachment. In the 6 months I've been using it I've used the 4 jaw the most, but the 5c's and 3 jaw have defininely seen their use also. I like having the collets.
 
You must log in or register to reply here.
Back
Top