Bit keeps coming loose

Anyone have any issues with the collet on the 611? It seems the bit is coming loose and then the carve just goes off track and dives into the block and sometimes breaking the bit. Its also pulling the blank free from its clamps. Ive tried really tightening it but dont want to over tighten.

I have never had this problem with the 611 or any other router before. Not to insult but are you using a 1/8 bit with the adapter?

No youre good. I havent either until this. Have used a ton of different routers.

No its a 1/4" bit. So no sleeve.

I was more curious if the 611 has any collet issues in the past.

Is you bit truly 1/4 shank or is 6mm?

I have a Kress with a 1/4" collet. I had the problem you describe when using a 6mm shank vbit. A quarter inch is 6.35 mm so you would think that the collet would be able to tighten an extra 0.35mm but that is not the case.

You should measure your bit shank with calipers. Sometimes European 6mm bits are sold in the US as 1/4".

If other bits don’t give you fits, it is probably the bit. That said, if your bit is an up spiral and you are lifting the workpiece, your cut may be too aggressive. Also remember that the up spirals will want to pull themselves down and out of the collet if the collet is loose.

Watch a bit slip down on Mathias Wandle

Harry, thanks for the info. I will check the bits again but I’m pretty sure theyre really close to being 1/4".

The difference between a 6mm bit and a 1/4" bit is 0.35mm
To the eye identical.