1/8" Bits keep slipping out of my 611

I get half way thought a project and the bit starts slipping, makes a nice hole then breaks. I can tell it’s slipping because the plastic stop on bit is not touching the collet anymore. Has anyone had this problem?
I have tightened the collet as much as I can and am afraid I will break it if I try any harder. I even ordered a new reducer from Amazon but the same thing happens. I just ordered “1/8” precision grade collet" from Inventables. I hope that works.


Were you using a 1/4" to 1/8" insert before you ordered the one from Amazon? If so the inserts are trash. They almost always cause problems. The correct size collet will treat you much better. Also where did you get your bit? Some of the cheaper bits from ebay are metric even though they are listed as imperial.

1 Like

check bit diameter. i have ordered bit sets in the past that ended up being metric or undersized.

1 Like

Yes I was using the 1/4 to 1/8 adapter that came in kit at first. The bits are from Inventables.

I will try it this weekend. I assumed it needed to go all the way up to the plastic stop.

I will measure them when I get home

Try using the collets from Elaire. I use them with the bits from Inventables and haven’t broken a bit yet.


RickPeterson probably already nailed the issue (collet adapter), but other issues may be compounding the adapter’s problems.

As Bobjewell already mentioned, “bottoming out the bit” (sticking it in as far as it can go), causes vibrations that allow bits to move.

Another thought it to thoroughly clean the bit and collet with alcohol to get any tiny bit of residual oil and/or silicone (from manufacturing or packaging) off.

Finally, I have had router bits that just liked to slip, and so I took a small diamond file and slightly scratched up the shank. That has worked for me a few times when nothing else did.

The precision collets made for routers do work well, and will probably completely solve this…


I have purchased the Elaire collets and the Precision collets and from my experience the precision are the best investment I made for the 611.

1 Like

Make sure the adapter does not have any debris in the slit. If there is anything there it will not compress.
I have 2 of them and never had bits slip out.

A long time ago, when I was but a grunt in a machine shop, one of the old machinists showed me a trick for fitting an undersized bit into a collette. He used a paper strip wrapped around the bit to increase the diameter ever so slightly, then clamped it down. Not the most elegant solution, but it does work.

I would buy the proper sized collette though.

+1 for Elaire collets.

1 Like

I got the new Precision callet. It now works perfectly.