Wednesday, February 25, 2015

Putting On The Brakes

I have had this router lift for 12 or 13 years. It is a nice piece and I use it often. One problem that I've had, over the years, was the bit raising up, on it's own. This is very annoying and wasteful. I've ruined a boat load of nice hardwood. I always blamed myself. I thought that I didn't tighten the collet enough or maybe there was some debris that kept me from getting a good grip on the shank of the bit. As I was cutting the lock miter joints for the mantle project, it happened again. I did notice that the little dial, that indicates the amount that the bit is being raised or lowered was moving as the machine ran. I assumed it was loose and needed a tightening. I discovered it was tight and that the vibration from the machine was causing the lift mechanism to turn. There are small, ball detents that are supposed to lock the lift in position, but they are inadequate for the job when running large, heavy bits. So, I took it apart and saw what could be done. I cut a clamp, to act as a brake, from a scrap of maple. I then drilled and tapped the lift base and bolted the brake to the base with some long bolts and some spacers that I cut from some aluminum tube from the scrap bucket. I grabbed an old  3/8 socket from the box of junky Chinese tools. The clamping bolt is 1/4 so it has a 7/16 head. I ground it to 3/8, put it in the socket backwards so the bolt extends though the square drive end is, and screwed it into the brake. There is a "T" nut on the other side. The crank to set the bit height is a 3/8 hex, so I can use it to set the brake. After a few minor adjustments, I gave it a test run. I put the big lock joint bit in, set the height, and tightened the brake. It seemed to work well, I couldn't turn the adjuster with the crank unless I backed off of the brake. I ran some wood through it and there was no creeping of the bit. I think I'll call this one a success. Another annoying problem solved.

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