Tuning pin drilling?

[Ron Nossaman]

> When you run maple through the back beveled set does it tend to burnish at all.
> My single bevel set can burnish when preparing thin laminate layers

If they're dull enough, sure. Otherwise, not enough to be 
troublesome. Sort of the difference between ideal, and practical.


> By the way, at your suggestion on the .272 bits with a 1/2"x1/4" diam. step, I sharpened the step
> to experiment with single pass 2 step drilling. So far they are yielding consistent 
> and acceptable holes on my guided/cooled drilling rig...I'm going to try it out 
> on an entire block...see how it does.
> 
> Jim  

Try some scrap, meanwhile, without cooling, if you would. One 
of the benefits of two step drilling with two different bits, 
is that the second pass doesn't generate enough heat to affect 
accuracy, so no cooling is necessary on either pass. I'm 
curious how that would work with the step drill.

Ron N