ER16 Collets from Ebay

Thank you for that.

Oversize ER32 collets are now on my need to get list

re ER 16 collets: - I bought a collet chuck and 8 collets for about CND $40. 00 from Ebay. The chuck is good and most of the collets. BUT the 0.125" size has a ,006" total run out. Checking it seems to indicate the bore is not concentric with the O/D.

I am not complaining because a pucka replacement 0.125" collet, (.0003" run out,) cost CND $25.00 plus $40.00 freight. The Chuck alone is good value despite the poor collet.

Has anybody tried correcting the errors and if so how?

If it is one collet that is faulty, just get another. I cannot understand how one Er16 collet can cost $65 even if they are Ca $!

.

The $40 cost of freight seems a good explanation.

… It makes what you get for the other $25 look pretty fair.

MichaelG.

The cost of freight is now close to or more than the small articles I buy on line. Many suppliers don't give options on carriers and a flat rate is charged but no indication of max weight for the money. Progress?

I'm afraid my experience of APT collets is less positive.

My current ER20 collet chuck isn't an APT offering but a fourth-time-lucky chuck bought elsewhere. There is, happily, negligible runout with it when using most of the very cheap ER20 collets that I originally bought with my first, very untrue, ER20 collet chuck (off eBay) and subsequently returned. I still have these original collets.

Recently, thinking I could improve on the runout on the most often used sizes (6, 10, 12mm) I bought "superprecision" collets in these sizes from APT.

The runout on these is unfailingly between one-and-a-half to three times as bad as on the bargain-bucket collets that came with my first ER20 chuck. No amount of rechucking makes any appreciable difference to the initially observed discrepancy.

Edited By Bill Phinn on 09/05/2022 17:39:22

So Bill what did you do with these out of spec collets from APT?

Tony

I did not see mention that they were out of spec, just not as good as the Cheapies. Bill may have got lucky and had some very good cheapies.

I have , by making a mandrel that is the upper size of the collet range. With a centre support and then super glue the collet in place. Re grind the outside 8 deg per side and then regrind the 30 deg per side for the front taper. Really a lot more time than it is worth. For a little extra time, a new one could be made. When they are less than 3mm diameter for ER16, it just becomes too flexible to easily get it right. On a 6mm or a 1/4 inch one the mandrel really is very substantial by comparison. I was not going to waste a piece of turnable tungsten to save a collet. Quite often the bore the and the main 8 deg taper are ok, and it's the front 30 deg taper that is out of whack. On a larger ER40 collet, I super glued the collet into the holder, and then very lightly put the front nut on. I just turned it out with light cuts and a sharp positive rake boring bar. Made a specific sized collet for a job.

Edited By Neil Lickfold on 09/05/2022 20:49:03

Thanks for the reply Neil. I shall not go down that route.

I have wondered how they are made.I suspect a powered metal blank including the slots, then heat treated and then ground. To do the machining I think they lock the collet slots using a plastic compound because I have found traces of such in some collets.

I unwrapped them for the first time three months after buying them, and after repeated testing just put them back in the drawer they're kept in.

I didn't say they're out of spec - I have no way of testing that infallibly - I just found them to be worse, on my chuck with my set-up, than the eBay ones.

If you want to PM me your contact details I'll send you one of them and you can test it for yourself.