router bit creep

[Gene Howe]

Hi folks.
Recently, I was cutting a 1/4X1/4 dado with a 1/4 spiral with a PC in a table. After about 12", the bit began to raise up out of the collet adapter. This happened again, after I changed bits from a down to up spiral.
I really can't tighten the collet nuts any tighter.
I have several adapters but, didn't change that. Should have I?
Any other suggestions would be appreciated.

Thanks

[Jason Beam]

Are you putting the bit ALL the way into the collet? If so, that might be your trouble. leave a good 1/16" of space inside that collet so that it can pull the bit down while it tightens.

[Joe Scharle]

Just last week I had the same thing on my big Milwaukee. New collet.

[John Lucas]

The apiral bits have a tremendous "urge" to move up pr down. The suggestions given so far are importent to follow. A 1/4" shaft doesnt have as mch of a grip as a 1/2" but mosyt all 1/4" spiral bits are with 1/4" shafts. All that I can add is to be sure bit and collet are very clean and free of o il and you re-tighten the collet after each use and dont route s fast as you might otherwise....and stay clear of the line of fire.

[Steve Kohn]

Several years ago I had the same problem with my PC690 router. Long story...change the collet.

Mine was deformed when I looked at it very closely. I never did figure out whether it was because I left a router bit in the chuck for too long, or whether I had a defective collet.

[Jeff Bratt]

Spiral router bits especially have a tendency towards Automatic Random Height Changes (ARHC). Make sure your collet is clean - free of oil and debris. Also make sure the router bit is clean and the mounting shaft is not damaged. Make sure the collet is not damaged or deformed. When you tighten down the collet, make sure the bit is slightly raised up off the bottom of the mounting hole, so the collet can tighten fully. And if all else fails, try a new collet.

[Richard M. Wolfe]

As the others said, raise the bit slightly before tightening the collet. I have had several different bits creep before and snugging the collet down remedied the problem for me. I don't see how anything could be at fault except the collet. I had a mixed reaction from the creep..... 1) several four letter words from ruining a workpiece and 2) scared the ---- outta me.

[Larry Edgerton]

You mentioned a collet adaptor? Are you using a 1/4" collet adaptor in a 1/2" collet? If so chuck the adaptor and buy a 1/4" collet.

As it has done it with two bits, it is the collet. If by chance you hava a really old PC router that has the two split collet, buy a modern PC collet. those old ones did not hold so well.

Get in the habit of cleaning the collet, and particularly the recess with compressed air regularly. Any buildup in the collet cup will cause problems.

I regularly use spirals in PC's so it is probably just an old collet. If a bit ever loosens up and spins in a collet it is junk, so if this has happened, buy new.

Next time, look for a 1/2" shank bit as it will have twice the holding power as the 1/4".

[Gene Howe]

You mentioned a collet adaptor? Are you using a 1/4" collet adaptor in a 1/2" collet? If so chuck the adaptor and buy a 1/4" collet.

Thanks Larry. I believe I will.

As it has done it with two bits, it is the collet. If by chance you hava a really old PC router that has the two split collet, buy a modern PC collet. those old ones did not hold so well.

Mine is the new style.

Get in the habit of cleaning the collet, and particularly the recess with compressed air regularly. Any buildup in the collet cup will cause problems.

I take it apart and clean it....but not often enough, I'd imagine.

I regularly use spirals in PC's so it is probably just an old collet. If a bit ever loosens up and spins in a collet it is junk, so if this has happened, buy new.



Next time, look for a 1/2" shank bit as it will have twice the holding power as the 1/4".

That's also on my purchase list.

Thanks again.

[Anthony Whitesell]

I had that problem on an old Craftsman Router. It is 1/4" only collet, so I cleaned it up and reseated the bit and didn't have the problem again.

I also had the opposite problem a few weeks ago. A few years back I opted to go with Bosch routers. I purchased the 1617EVS for handheld work and a separate motor for table work. The motor came with a pair of collets but until a few weeks ago I had no need to have the same size bit in both systems at once. I needed the table and handheld routers chucked with 1/4" bits simultaneously so I finally open the package. When I inserted the bit into the new collet it was a peculiarly tight fit. When I tried to remove the bit afterwards I found I why. I could not get the bit out (I hadn't bottomed) but it was stuck. I ended up unscrewing the collet and driving the bit out with a 1/4" drift and a ball peen hammer. I called Bosch and they sent me a new collet which works fine.

[Cliff Polubinsky]

Gene,

I had that problem a while ago. Turned out to be a problem with the router - it was rotating off center and with the longer bits, like a spiral, it would vibrate the bit out of the collet. I thought it was the bit until I put in a bowl bit with an extension and really noticed the off center rotation. Wasn't a problem with the shorter bits. Just the long ones. Porter Cable replaced the router.

Cliff