Hi John, For the screws I have learned to use this technique that works ok - it is a two step process and I like it better than a tapered bit for the big pin block screws. Measure the shank (may be the wrong terminology - sorry)of the screw and add 10% and that is the drill size for the threaded part. Flag the drill for depth and dirll the hole. For the shoulder, use the same drill size as the shoulder, flag the drill and redrill the hole to the depth of the shoulder. Add just a dab of Teflon powder to make it easier to cut the threads. Gene ----- Original Message ----- From: John Ross To: Pianotech List Sent: Tuesday, September 01, 2009 2:17 PM Subject: [pianotech] pinblock Question How do you predrill the holes for the screws? It has been a while, and I can't remember what I did previously. I have the tapered bits from Lee Valley, but the screws are still too tight in the test piece of pinblock. The taper is all wrong for the 'fat' screws. I was thinking, of double drilling, part way with the thicker one, then go with a smaller size, same as the shaft thickness. Other question is, I am going to be using #1 pins, and want to use 'the Nossaman' system of double drilling, rather than using the air stream to cool the bit. What size for the first and second passes? John Ross Windsor, Nova Scotia. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20090901/8f8abf87/attachment.htm>
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