Modifying router bits

A lot of stuff I do with my tilting router lift requires router bits without a top guide bearing, so I figured I'd write up a short article about modifying the router bits for this purpose.

For example, this bead molding can be made with a round over bit, provided that the guide bearing is removed.

The guide bearing itself is easy enough to remove...

... but the bearing post still remains. Sometimes, just removing the guide bearing is enough, but for this bead molding example, it's not enough.

Most of the guide post is easy enough to grind down on a bench grinder.

To do the final flattening, I have to use the corner of the wheel. It's necessary to cut lower than the carbide cutter edges to prevent the remaining metal from rubbing against the wood. It's ok to nick the inside edges of the carbide a bit.

The flattened bit. This one was quite easy. I had a bevel bit that I flattened where the top edge of the carbide caused some burning, and I had to cut that back a bit. The carbide really doesn't cut very well on a bench grinder. But a diamond wheel tile saw was able to cut the carbide. It was a bit rough though, the tile saw's wheel's effective grit was much too coarse.

With the bearing removed, cutting the beads is easy.

All the bits I have modified so far came from one of these cheap router bit sets, which came with my router. I think it added about $20 to the price of the router, so it comes to about $1 per bit. I have two identical sets of bits like that, so I wasn't too worried about accidentally destroying one. So far, haven't wrecked one yet.

See also:

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