Workers Of Wood

Was playing in the shop and cutting a 3d model as a test run with a 1/8 inch ball nose. When I got ready to take the bit out of the machine, the collet fell out in two pieces. Didn't over tighten, didn't hit anything, but it just broke. I'm assuming that it was a manufacturing defect, it is the one that came with the machine. Now I have to try to find an ER 20 collet around me. Ordered one from Amazonian Jungle and it won't be here until Saturday.

In this season, there is no telling when something will show up. I ordered dog food (special prescription type) from Chewy and not only was it late, the LostEx (Fedex) driver simply marked it as refused. Now I have to drive 100+ miles one way today to get it. Needless to say, that was my very last order with that bunch.
Mike

Sorry to hear, Mike...

Is it possible the collet/nut may have been tightened down without a bit at some point...?

It was new and never been tightened without a bit, so i am assuming that it was probably made in China where the quality control is iffy at best. I ordered a new one that is made in America.

In you folks opinion, who makes the best ER 20 collets?

Mike; you don't need "the best", you need one that's competently manufactured. A giant leap of faith on my part but I'd think any North American tool maker that makes their parts here in NA would qualify (or German or Italian made as well).
The quality of the steel is paramount. Pretty much disqualifies China...

I actually think that the problem is me, not the collet. I am new to this and have been putting the bit in the collet, placing the collet in the spindle then putting the collet nut over them and threading them. I was told that I need to snap the nut on the collet insert the bit then thread onto the spindle. Just assuming that this is truly operator error rather than the collet.

This doesn't change my thoughts about China, they make junk, put nuclear waste in products (not really, just an extreme illustration) and I would prefer to avoid anything Chinese. Good ole' American manufacturing is still the world standard, but the Chinese are like Walmart, undercut everyone until you put them out of business, then you have a monopoly and can charge anything you wish. Just my $0.02 this morning!

Yes. I know nothing about CNC spindles, but how or why are they different than a normal router armature assembly?
On a normal router nothing gets removed or disassembled. You simply loosen the nut (past the second tight spot), then pull the bit out and insert the new one, then tighten the nut securely. Pulling the collet sleeve and nut apart is normally only done for cleaning or replacement of the collet sleeve.
As I said I know nothing about the CNC side of it but why would it differ?

Mike...I agree with Dan...it doesn't seem there should be a difference between what you have and normal router bit replacement...Unless you're also changing bit shank size. Just wondering...