>> I first make the marks with a sharp punch, then use a centre drill and >> finally drill (right through or not, depending on the piano) with a >> special (German) wrestplank drill which has a more acute point than >> the jobber's drill and a faster spiral. If drilling a pilot hole >> right through would make the result more precise, I'd do it, but I >> don't see that it would. However I would never consider using the >> wrestplank drill without first using the centre drill. > > > > > I would never use a brad-pointed drill and I would never use any drill, > no matter how dear or cheap, that did not have the fast helix angle. > > JD I like center drilling. I punch, center drill, and double drill in pianos without plate bushings. All blocks are drilled in the piano, with the plate in it's final resting place. Brad points aren't much good drilling through bushings, if the piano has them, but if it does, the punch and center drill are superfluous. In either case, I don't use brad points. I never found the need for high helix with the two bit method, though I have used them back in the single pass days. I don't like the way they burrow in. In the end, I don't suppose it matters if we punch holes in pinblocks with micrometeorite strikes if we can produce what we consider an acceptable job in the process. Ron N
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