Do I Need A Collet Chuck?

I like all collet systems and I also like to bore soft jaws on a chuck. I have a full set 5c collets plus a metric set plus square and hex sets. Also have rubberflex collet chuck. I have about 6 collet chucks a 2j chuck a 3j chuck and I like them all. ER collets work great for round stock. BUT if you need a .06 wide x 4 inch dia piece of stock held it can be done with a 5c step collet. A piece of hex or square stock can be held in a 5c collet. Up to size limits of collet. I can take a collet chuck off my lathe and move it to the mill and do other operations on the part. I can and have many times put a soft 5c collet in a collet chuck on the mill and moved it off center and made an excentric collet. Many times I bore a collet for a part then move the collet to the mill and drill the hole pattern there. I also love inside collets and you can hold on the bore of a part and finish the outside with ease. You can buy 5c inside collets up to 6 inch dia from Rovi. I even have a collet chuck that fits a W&S turret lathe that holds parts up to 6 inches. Hardinge makes some great collet index fixtures for 5c collets .I don't think they make any other index fixtures for other size collets. I have been owned 0r worked in a machine shop for over 60 years. And I think I gave a few good reasons for having a collet chuck.
jimsehr
 
I have a 5-c collet chuck from CDCOtools on my Clausing 5418, a 4-c hand wheel collet closer on my Rockwell 10 x 36 and a lever style 5-C closer on my Grizzly G0709. Collets are great for the reasons mentioned above, I'd hate to be without them on my lathes. I do a fair amount of turning with brass, love the collets for no marring. I must have gotten lucky with mine, all measure 0.0002" at the spindle or better. My Grizzly usually has a 6" 3-jaw mounted, the Clausing has the collet chuck. Nice to pop back and forth on the lathes instead of changing from collets to chucks or vice versa.

Curious, has anyone looked at G4026 collet closer for a G4003 lathe on the G4003G lathe? Probably have to make a new draw bar, but that's not too bad of a job.

Bruce
 
If you are a serious tool guy, then you must have at least one of everything. But if not, I would spend the money and get the very best NEW 3-jaw chuck WITH ADJUST TRU that you can find. I have more 3-4 jaw chucks and collect holders than I need. Do I use any of them? No, not at least to justify their taken up space in my shop. I have a 3-jaw Buck that has been my go to chuck since day one. And it’s sweeeeeet! The chuck is the heart of the lathe. Don’t skimp out on a low quality chuck. Or one with re-ground jaws, thinking it will be OK after it has been re-worked. Spend the money and get a good chuck. The chuck could cost more than the lathe! Same story with the tool holder!…Dave.
 
Lets go back to the crux of the question
minions said:
especially since most of my machining is on smaller aluminum parts.
Click to expand...
Do you need repeatabillity in holding similar parts? Multiple runs of the same job? Remember you cant adjust for runout in a collet, but you can with a chuck. Sure colletts are great, but they, (like every thing else) have their limitations. Dont assume a tool will make a machinist of you. It takes a machinist to make a tool of himself!

Cheers Phil
 
Minor terminology point since this is the "Beginner's" forum. A draw bar is normally solid with external threads. Like the 3/8"-16 ones that are common on smaller lathes and most mills. Most of the collets that have been mentioned in this thread (except for the ER and Rubberflex) have male threads. The device used to pull on them to tighten or close them most of the time is a draw tube,.

Collet chucks, except again for ER and I guess Rubberflex, are usually only used so that you can run collets that are too large to fit into your lathe's hollow spindle. Or actually the closer adapter is too large. This is an issue with using 5C collets on most lathes under about 14" although the swing itself has nothing to do with it. The spindle through holes are usually too small (there are a few exceptions). Collet chucks have several disadvantages. First, decent ones are expensive. Second, you have to stop the machine in order to change parts. Third, they stick out from the spindle nose several inches, and their runout is typically worse than with a collet that you can mount right in the spindle.

To get back to the original question of should you buy another5C collet chuck, I'm not familiar with the G4003G and don't know what the spindle taper is. If it is 5MT or larger, if you buy anything, buy a 5MT to 5C closer adapter and a 5C draw tube. I don't guarantee that it'll be cheaper but odds are that the runout will be less than with the average 5C collet chuck. I don't recall whether 4MT or 4.5MT are large enough or not. If it's 3MT, first consider how much of what you need to work on is actually larger than 1/2" diameter. If all or most of it is, then your only option for collets is a collet chuck for 5C (or some other probably more expensive large collet). If most or all parts are no larger than 1/2", then go with 3C collets. I actually use 3AT on my Atlas, but then I'm part collector. 3AT is native to the Atlas. ;)
 
OK. Then you do not really need a collet chuck. What you need is a 5MT to 5C closer adapter (this is a short flanged hollow cylinder a little shorter than a collet that is male 5MT on the outside, female 5C on the inside, and with a key peg visible inside to slide in the collet keyway) and a 5C draw tube with a length from the end of the internally threaded right end to the thrust bearing on the left end such that with a collet properly closed on a test piece of the exact nominal diameter that the collet is made for, approximately 50% of the threads on the collet are engaged. The least expensive ones will have a handwheel and thrust bearing on the left end. Unless you expect to be making relatively large quantities of the same part, the handwheel type will be the least expensive, or you can actually make it if you wish. But if production quantities and the required operations warrant, there is the considerably more expensive lever type which can be operated without stopping the machine. It has one other disadvantage besides cost - you do not want to leave it installed if you are running any operation that does not use it. Which means setup and tear down time. If the machine has a threaded spindle, you will also need a thread protector that doubles as a collet adapter remover. If not threaded, you will need to buy or make a remover bar.
 
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