[pianotech] pinblock drilling clamp

[Mike Spalding]

What seems to have worked will during preliminary testing:  Set the 
table height so that the tip of the bit is just above the top of the 
pinblock.  Position the pinblock so that the pilot hole is aligned with 
the bit. Feed the bit just far enough to confirm or fine tune the 
alignment. Set the clamp, drill the hole.  Takes longer to describe than 
to do.

What I like about double drilling on the drill press:  I can drill the 
pilots, invert the pinblock and clean up the splintered drill exits with 
a countersink, then do the final drilling without creating additional 
splinters on the bottom.  So the pinblock is sitting flat and steady on 
the table, not rocking on chips which I suspect contributed to 
inconsistent drilling.

I agree, Ron, the objective is to make luck irrelevant.

Mike

Ron Nossaman wrote:
> Shawn Hansen wrote:
>> 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.
>
> One of the inescapable characteristics of double drilling is that it's 
> nearly impossible to NOT center the second pass on the first hole. It 
> self centers automatically. The only way I can think of to screw it up 
> is to clamp it securely enough that it can't self center. The method 
> was designed around this phenomenon. Defeat the phenomenon, and you 
> invalidate the method.
>
>
>  > good luck with the double drilling.
>
> I have very good luck with the double drilling, but then luck really 
> has nothing to do with it.
> Ron N
>