Modifying A

■ For the Oval Mirror profile, I wanted to rout a bead in the center of the frame. To do this, I needed a round-over bit without a pilot bearing. But most round-over bits are designed to rout the edge, so they have a bearing.

At least one source has a W carbide-tipped round-over bit without a bearing (see page 31).

A less expensive option is to buy a high speed steel bit (26309) and arbor set (2589) from Sears. This bit has a removable rub pilot, but there's a problem when using the bit this way.

The end where the pilot is usually screwed in isn't made to cut wood. As it spins, this flat end burns the workpiece, see photo.

To prevent the burning, I ground a concave shape on the bit using a grinding wheel, see Fig. 1. Just hold the bit with locking pliers and use the corner of the grinding wheel. Grind from the center outwards, being careful not to nick the cutting edge.

BEFORE: The bit with the flat end is difficult to push through the workpiece, and the friction it produces burns the wood.

AFTER: With the end of the bit hollowed out, the cut is much smoother, and the workpiece shows no signs of burning.


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