Bolduc Block - Bit Size - Torque

[John Ross]

Thanks Jim.
I had forgotten rate of penetration, having an effect as well.
I must save the info this time.
Although, I usually use a scrap piece of pinblock, and experiment with the
insertion rate.
One should always direct a stream of air at the bit. If one had spare money,
one of Webb's vortex coolers is ideal.
Regards,
John M. Ross
Windsor, Nova Scotia, Canada
jrpiano@win.eastlink.ca
----- Original Message ----- 
From: <JIMRPT@aol.com>
To: <pianotech@ptg.org>
Sent: Wednesday, June 18, 2003 6:59 PM
Subject: Re: Bolduc Block - Bit Size - Torque


>
> In a message dated 18/06/03 5:33:22 PM, jrpiano@win.eastlink.ca writes:
>
> << The speed you drill at has an effect on the size of the hole, one way
the
>
> hole is larger, the other smaller, with the same size bit.
>
> I forget which is which, but too fast is no good and neither is too slow.
>
> Possibly someone can remember the speeds that should be used. >>
>
> John..... you are in agreement with my thoughts here. There are many
> variables as to the answers and among them are, speed of drilling (not
only rotational
> speed but vertical penetration speed), sharpness of bit, type of bit
(shape
> and structure of point), single pass/double pass, type of block being
drilled,
> whether bit is cooled frequently, etc., etc.
>
>  In my experience the slower you drill a hole the larger the final product
> with a faster drilling speed producing a smaller hole...but that is just
my
> opinion and is backed up with no objective evidence.
>
>  I drill my blocks with 600/800 RPM and use a .250 bit for 2/0 pins. This
> works very well on multi-layer blocks as well as S&S/Bolduc type blocks.
Single
> pass, two insertions per hole. With this combination, and the use of pin
> driving fluid, I end up with very workable chipping/tuning torque values
which
> settle down to a very nice 'regular' tuning value. I believe personally
that values
> of over 150 are overkill not to mention counterproductive.....but that is
> just my opinion.
> Jim Bryant (FL)
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