On Wed, 28 Nov 2018 17:36:09 -0800, pyotr filipivich
wrote:

Greetings

I have a harbor freight router table, which "mostly works".

However, the problem I'm having is getting 1/4 collets tight to
hold the router bits. It seems to me that first I must tighten up the
collar really tight ("till it snaps, then back off a quarter turn"),
before I can get the router bit to stop sliding in or out.
This gets to be a problem when I'm having to set a height at the
same time. So far I've been able to support the slot cutter bit to
the height above the table with a bit of wood scrap, then proceed to
tighten things up. But as I said, it seems that I've tightened the
collet "to murder tight" and it "should" be holding, but I can still
wiggle the router bit.

So, is shimming the collet in some manner a "good" idea? Let me
rephrase that, it seems "a good idea" , but is it a smart one?

Before you shim, clean. Get the inside of that collet spotless--a .25
caliber pistol cleaning kit is your best bet. Use the solvent in the
kit and follow up with lacquer thinner.

I ran into a similar problem with a Porter Cable, and cleaning the
Hell out of it fixed it.

If that doesn't work then I don't see any reason not to shim as long
as you've got enough clearance to get a shim all the way around the
bit so you don't decenter it.