point bits from the catalogs, are ground on special wheels in special
jigs. No need to follow this exact shape though. I have
been grinding my own bits for years, from ordinary twist bits.
They cut every bit as good as anything I ever bought. It only
takes a couple minutes to do it too.
Lets dig in.
Here is an ordinary 1/2" bit I grabbed off the pile
of junkers. Not even an expensive bit. For wood drilling
you won't notice any difference. I get years of service unless
I screw up and hit metal with the bit or something.
Line it up on the -corner- of a grinding wheel. I
hold it freehand with just the backs of my fingers resting on the
tool rest for support.
You want the corner of the wheel centered about 1/2
way on the old edge. Leave yourself plenty of clearance. Unlike a
metal cutting bit that needs all its strength, a wood bit does just
fine with ample clearance.
Work the bit into the stone, cutting both the face
and side at the same time. You will adjust slightly as you grind.
Changing angle a bit and working the point and the cutting edge as
you get the angles you really want. You want a fairly long point and
sweeping side cutters.
Here is 1/2 the bit ground but I will probabyl go
back at the very end to match up both edges.
Here is what you end up with. They cut astoundingly
easy in the hardest woods.