Preventing router bit from slipping...

[jcrenick]

I was routing a recess in the back of a cabinet door to accept a piece of glass when I noticed that the recess seemed deeper. I checked the depth and yes the depth of the cut had grown. This happened twice during this project. Each time it was due to the bit "rising" out of the collet.

Each time I tightened the collet I did so pretty hard so I don't think that is the problem. This was a new bit. Is it due to machine oil residue on the shaft? Is my collet worn out? What can I do to ensure this does not happen again?

[John Hunter]

I had the same problem with a brand new bit I bought on sale. It turned out it was slightly undersized and the collet could not properly get a good grip on the shaft. Of course you could also have a problem with the collet.

[Lonnie in Orlando]

Similar thing happened to me with an old B&D 1/4" router in the router table on my BT3000. I replaced the collet -- solved the problem.
- Lonnie

[jcrenick]

Thanks I will check into a new collet.

[afleischer]

I actually had this happen to me and I figured out why.

I was running a 1/4" groove in purpleheart with a spiral bit and due to the hardness of the wood and the spiral in the bit it was actually pulling it out of the router.

In this case, it actually came through the top of my piece...I was lucky it didn't fly out of the router.

So next time I am just going to use a straight bit and make multiple passes on super dense wood.

[Wood_workur]

could it be you router motor sininking down in the base?