When double drilling, I am most worried about getting the pinblock in the EXACT same place as the initial drilling. Most of the suggestions I have seen for initial to final drill sizes can be as little as .010" difference. It is hard for me to feel comfortable thinking that the 230 or so times I drill this block the second time, I will be within 1 blue paper punching every single time. I just think I have increased my chances of being inconsistent. Instead I have returned to the single drilling way I was taught by David Betts: consistency and accuracy I can control is done with the same drill speed, AND the same drill feed into the block, every single time I drill. (and a fast spiral drill bit gets the chips out and lets me feed at the speed I have tested for.) Once I get the drill bit speed and the feed speed set, I rarely have problems with the block riding up on the bit. On the other hand, I like the gate and clamp that you have made there a lot and I am curious to hear how it works out for you! good luck with the double drilling. Shawn On Wed, Aug 11, 2010 at 7:03 PM, Mike Spalding <mike.spalding1 at verizon.net>wrote: > I learned to drill pinblocks out of the piano, and even though Ron N's > arguments for doing it in the piano are quite compelling, have never gotten > around to setting up for that process. Step one, find a radial drill press. > Nope, not yet. But I need to improve the consistency of pin torque, and > thought that double-drilling might be the answer. I know from painful past > experience that you need a pretty effective hold-down for the second drill, > else the workpiece will climb up the bit until it hits the chuck, then > commence to spin. At that point, all pin torque consistency is gone. So in > preparation for my next pinblock, I've prototyped a hold-down clamp. > Thought you might be interested in seeing this.. The photo shows test > holes being drilled in a piece of pinblock scrap. pilot drill 7/32, final > drill "F" .257. Pins in the test piece are reasonably consistent - 125 to > 150 in-lb. Of course, the real test is 224 pins in a real piano, so I'll > let you know later how it works in production. Meanwhile, I'm curious if > anyone else has taken this path, and if so, with what result? > > > -- Shawn Hansen RPT certified piano technician 816.896.4047 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20100811/3ad668d5/attachment.htm>
This PTG archive page provided courtesy of Moy Piano Service, LLC