[pianotech] Size of Pinblock Drill bit?

[Ron Nossaman]

On 3/6/2013 4:46 PM, Jim Ialeggio wrote:
> Interesting bit (haha) make that idea I got from Bruce Clark and Jason
> Andino at the Haverhill WNG training class:
>
> First pass 1/4" drill of the type you prefer, I'm using a fast spiral so
> I don't have to take 2 or 3 plunges to clear the bit. Then for the
> second pass, by hand, fast spiral "nubbed" bit.  Doesn't grab and pull
> through, and doesn't beat up the start of the hole.

I see no benefit to high helix on the second pass, though the nubbed bit 
is standard for drilling bridges out from #6 to #7 pins when using the 
original cap. If you mean grinding near vertical bevels on the cutting 
edges of the bits, that is. Another old machinists trick, like double 
drilling itself, for cast iron, that works very well in wood too.

Ron N