Router Bit movement.

[D.McDonnel "Mac"]

Last night I was making about 70' of quarter round using a 1/2 inch radius, 1/2 inch shank router bit in my PC690 table mounted router. I fussed with the setup untill I had the bit cutting a nice smooth radius. About half way through the run I noticed the profile had shifted slightly. I checked and the bit had slipped down slightly. The collet had loosened up slightly. I repositioned the bit and retightened but it left me wondering why it had come loose to begin with!

Anyone have experience with this? Do I need to recheck the collet tightness every so often? I've run a lot of wood past that router and do not remember this happening in the past. Any suggestions?

Mac

[Jim Becker]

What make and model of router is it, Mac? There are some older Craftsman routers, for example, that would "loose their grip", causing the bit shift you speak about or worse.

[Dale Sandford]

I've never had in problems with the collet on a Porter Cable 690 holding the bit. Perhaps there was some dust or debris between the collet and the bit when it was originally tightened. Under load the debris might get crushed or work its way out leaving the bit loose.

-- Dale

[Jesse Cloud]

Hey Mac,
I have had this happen a couple of times over the years. I would try giving the collet a good cleaning - blow it out with compressed air if available, and if that doesn't work, spring for a new collet. They don't cost much and the risk of messing up some good wood just isn't worth it.

[Steve Clardy]

Only one instance of that with my pc routers.
Brand new router. I had not cleaned out the oil that is on, in the collet and shaft that comes on them.

Cleaned it up with thinner.

[Lee Schierer]

This seems to be a problem in routers with only a single split in the the collet, particularly as they get older and worn a bit or dirty. It also makes the bits hard to release. My 6 finger collet for my Freud router has never slipped even once.

[Doug Shepard]

I've had it happen on my DW laminate trimmer and after a few times decided it was time to replace the collet. Since then, no problems.

[Steve Clardy]

What make and model of router is it, Mac? There are some older Craftsman routers, for example, that would "loose their grip", causing the bit shift you speak about or worse.

Wake up Jim.:eek: More coffee:D

PC690

[pat warner]

Quite possible the collet slipped. 15 in-pounds is typical collet nut tightening torque. Maintain that with clean collet, clean collet seat and burr free shank; cutter won't slip. If you stall the router that is another story; it may indeed slip.
I suspect your motor spun in its casting (changing depth). If you have conventional OEM thumbscrew lock, I'd bet on it. In any event, you should not have to check on this during a run. Collet should hold its cutter and motor lock should hold its motor barrel fast.
Consider a new lever instead of thumbscrew. Sample on 310 in pix link. (http://patwarner.com/images/310_subbase3.jpg)

Routers (http://patwarner.com/index.html)

[Howard Rosenberg]

Assuming you're seating the bit correctly in the collet and tightening the collet correctly - - -

The clamping mechanism that tightens both halves of the router body might be loosening a little bit and it's the ROUTER MOTOR that's slipping.

Check the clamping mechanism. See if it's as tight as it should be.
Pat Warner shows mods to the P-C 69x-series bodies to maximize tightness.

HTH
Howard

P.S. - Let us know what you discover.

[Jim Becker]

Wake up Jim.:eek: More coffee:D

PC690

DOH!!

Sorry Mac...I guess I, um...missed that little detail. Oy, veh! I need a vacation. Yea! That's the ticket!!! :D Later....;)