On Wednesday, November 28, 2018 at 8:35:34 PM UTC-5, 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?

You have "a harbor freight router table". Do you also have a Harbor Freight router? It might not matter, although a router is one of those tools on my
"buy quality" list.

Anyway...

I've got no issue with J's suggestion to clean the collet, but "murder tight
and the bit still wiggles" seems like more than just some dirt.

Is it all 1/4" bits or just the slot cutter that you mentioned? Maybe
there's an issue with the bit itself. I bought an almost brand new PC
router at a pawn shop. It came with a bit that had a collar around the
shank. I had never seen that before. Turns out it was an 8mm shank and
the collar was an adapter to get it to 1/2". Have you measured the shank?
Is it a full 1/4"?

Can you swap the collet for a 1/2" and use 1/2" bits? Less vibration,
which I think would be important for a slot cutter.