router bit working way out of collet

[Dan_Shade]

I was cutting some grooves this evening with a spiral router bit, and it walked out of the collet twice.  The second time, i had it really tight (I thought).  I'm using the router in a router table.

I was cutting  1/4" depth by 3/8" wide, in one pass in white oak.  it was cutting good, then would start to chatter, and start working up.

Any tricks to this?  or is this common?

[John Bartley]

The most common reason for a bit to loosen is because it was pushed to the bottom of the socket before it was tightened. Collets work by tightening a tapered outer sleeve around a bit and pushing the bit "down" into the socket. If the bit is bottomed out before tightening happens then it has no where to go and cannot be properly tightened. Even if you lift the bit by as little as a 1/32" above the bottom of the collet, it will have room to sink into the housing as it tightens.

There are other reasons also, but this is the most common one.

cheers

John

[Dan_Shade]

I thought that may have been the problem the first time, so the second time, i lifted it up a little bit.  Maybe I didn't go high enough?

[DouginUtah]

Is it a Craftsman router? This has been a common complaint of their routers.

[Dan_Shade]

hitachi (I think)

[Jasperfield]

I agree with John's post, above.

[logwalker]

Take your collet out and clean it really well.
Especially in the gaps between the shoulders. That is a start, anyway.

[LeeB]

Check a different bit and see if it is the bit. If so ditch the bit. A flying bitt can do fatal damage. If the new bit does the same I suspect rust or trash in the collet.

[low_48]

1/4" or 1/2" shank? Spiral, by their nature, should come out easier if all is not well. The up cut spiral will try and lift the bit out of the collet. It could be the age of the collet. They can wear into an hour glass shape with lots of use, and not keep a good grip. In fact that will cause more vibration and loosen much quicker. I don't think your cut was excessive, as long as you weren't feeding too fast.

[zopi]

might take a very fine grained sandpaper and rough the shank up a bit..and roll it tightly and rough the inside of the collet up just a TINY bit...the tolerance on some collets is a bit close...

[Dan_Shade]

it's a new bit.

I'll check the collet closely today, and also measure the bit diameter.  it's a 1/2", but I'm wondering if there is a manufacturing defect.

[Radar67]

Take your collet out and clean it really well.
Especially in the gaps between the shoulders.

Had this happen once before and it was sawdust in the gaps of the collet.

[Larry]

I bought a new Hitachi almost two years ago mail order.  I was quite disappointed to see "Made in China" on it.  I was amazed when I saw the collet nut...it was square!  So a manufacturing defect or lack of quality is in the realm of possibility.  I might try roughing up the collet a bit as zopi suggested...as a last resort.

To be fair the router has been excellent.  I've been using it with a pattern bit to cut window/door holes in my house through 7/16 osb...as fast as I can push it.

[treecyclers]

I would check the following:
1) Use some cleaner (I like Simple Green) to ensure that the shank is very clean.
2) Take the collet apart, and clean it real well too.
3) As the collet is drying, double check the threads to ensure they're clean and sound.
4) Using 600 grit or finer sandpaper, rough up the shank on the bit in a pattern similar to honing an engine cylinder - crossing twist diagonally around the shank.
5) put a cabinet door bumper ball in the space between the bit and the shaft, inside the collet - they have almost no mass, won't affect the rotation of the shaft, and prevents the bit from being jammed up into the collet completely, avoiding bit walk.
6) IF all of the above fail to accomplish the objective, Ebay that router, and get a Porter Cable.

[D Hagens]

I agree with the comment on Craftsman, seems to be a big problem with them.

I would chuck the collet and buy a new one. That or repair it and buy some good safety glasses....hmmm.....what would be cheaper?

I've had a few blow up on me, need a very good feeling thinking about a bit hitting my eye.

[DR Buck]

Dan,

You like to weld.  Weld the bit in.  ;D

[tomsteve]

I bought a new Hitachi almost two years ago mail order.  I was quite disappointed to see "Made in China" on it. 
  uuuuuuhhhh. notice the name? maybe shoulda been made in mexico???? ;D