Double drilling pinblocks: Hand held versus drill press.

[Carl Meyer]

David, I've drilled a block or three free hand, but not double drilled.
Before I built my pinblock drilling machine, I did turn an upright on it's
back, fill the pin holes with epotec epoxy and then drill the holes by hand.
The drill size was enough to use oversize pins (Don't remember the sizes
involved).  I considered it successful, but no amount of ingenuity and
foresight on my part has resulted in perfect torque no matter what procedure
I've tried.

My gut feeling is that double drilling by hand would be iffy and I wouldn't
think accuracy would be improved.  I'd speculate that making the first drill
no more than maybe 2/3 the final diameter would give the second drill a
better chance of alignment by hand.  That would then eliminate the heating
effect.  The drill I used had a bubble to hold the drill perpendicular.  I
think that helps.

I recall asking Willis Snyder many years ago if double drill pinblocks was a
good idea.  He said
"That works with metal but not wood."  I wish I'd asked him why.

Sometimes I'm surprised at how well pin block torque works in spite of all
the variables.  Rather than getting obsessed with a few looser than I'd
like,  I give them the ole ca (crazy glue) treatment.  It's only guaranteed
for life anyway.  That's my life of course.

Carl Meyer Ptg assoc
Santa Clara, Ca.


----- Original Message ----- 
From: "David Love" <davidlovepianos@earthlink.net>
To: "Pianotech" <pianotech@ptg.org>
Sent: Saturday, February 07, 2004 2:13 PM
Subject: Re: Double drilling pinblocks: Hand held versus drill press.


> I'm not sure we're talking about the same thing.  I'm refering to pinblock
> drilling in two passes.  If your final bit size is to be .261", then you
> predrill at .250" and on a second pass, drill the remaining .011".  On the
> second pass, because so little material is taken, you don't have to worry
> about feed speed and the drill heating up.  My question is whether that
> allows you to drill with a hand held and still be accurate without
> enlarging the hole.
>
> David Love
> davidlovepianos@earthlink.net
>
>
> > [Original Message]
> > From: Michael Gamble <michael@gambles.fsnet.co.uk>
> > To: <davidlovepianos@earthlink.net>; Pianotech <pianotech@ptg.org>
> > Date: 2/7/2004 1:46:50 PM
> > Subject: Re: Double drilling pinblocks: Hand held versus drill press.
> >
> > Hello List and David L
> > In the metal engineering world there is an old "dodge" that by initially
> > sharpening a drill bit so that one cutting face is longer than its pair,
> the
> > bit can be made to cut oversize. How does this help? It follows
therefore
> > that the drill you use to cut a "hole-in-one" must be very accurately
> > sharpened. You can get away with this to a degree by using a "roughing"
> > drill followed by a "finishing" drill. In an earlier post I suggested
that
> > to make a drill cut more precisely to its stated size the cutting
corners
> > should be rounded off. OK?
> > Michael G (UK)
> >
>
>
>
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