Double drilling pinblocks: Hand held versus drill press.

[David Love]

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)
>