DeWalt 611 Hot Collet

Does anyone else’s DeWalt 611 collet get very hot after short (~20min) cuts? I just noticed this after attempting my first cut with a bit change in the middle.

Heat creep from the motor.

I take it that it’s not an issue long term?

Nope. I’ve run mine for almost a full day, 20ish hours straight. No issues.

There is a lot of factors that could cause your “hot collet”. 1 - bits dia… comes into play big time. 2 - Cutting speed combined with cutting depth. 3 - Router RPM and 4 - Material being cut. Trim routers are not designed to be ran hard for long periods of time. They are designed for light duty, work. That said, yes you can run one for a long period of time provided you’re not using a 3/4 inch dia straight bit, making a 3/8" deep cut at max rpm through black walnut.

I come from a woodworking background, got into using CNC as just another tool. Most other CNC users are using these small 1/8 inch (or less) dia bits, that don’t take much to power them.

Here’s some tips that might help.

  1. NEVER push the bit all the way up into the collet. Push it in and then back it out a couple of hairs. -- This will prevent the bit from locking up inside the collet, or making it impossible to removed until cold.
  2. Look at the bit you're using --- dull bits need sharpened or replaced as they build heat, make the motor work a lot harder, and give make crappy cuts.
  3. Match the bit size to cut depth. Yes, i have taken a 3/4" 1/2" shank 1 1/2" long straight bit and cut through 1 1/4" white oak in a single pass... but it was done with a 3+ hp motor and cutting very slow... and on a bet that it could be done without burning the wood or bit. :)
One other thing that can cause not only heat, but a quick death to the bearing in a router or spindle is the length of the bit. I see these videos and look at photos and see these bits barely into the collet, sticking out as far as possible without falling out. That spells trouble! First of all, a router is made to sit flush on the surface it is cutting, in design to use the shortest possible bit to get the job done. Hence the vast array of lengths of each style and diameter of router bit. The for instance are not designed to use a 1/2" dia x 3" cutting height to make 1/8" deep grooves. And that is using a sturdy router base to support it and the cuts. Having a long skinny narrow ( 1/4" or less bit) sticking out 2 inches below the base plate is DUMB, DANGEROUS, and just stupid. A long shank hanging free even when only making shallow cuts puts a lot of side pressure on the bit, and against the collet, and in turn the motor bearings. I see it in Youtube videos and read about it all the time where these little skinny bits snap. Keep the length of the cutting bit as short as possible. With deep cuts, make half of the depth of all the cuts and then pause or use a tool change code.. then lengthen the bit some for the rest of the cuts. I have many times adjusted my bit length several times when working with deeper cuts.

Good luck and have fun.


P.S. One other thing that can cause the collet to get hot quickly is a loose bit. Is the bit isn’t 100-percent tight, which is much more than finger tight… it could be catching the workpiece and that friction will make the bit and collet very hot, very fast.

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