Drilling & pinning Falconwood Pinblocks

[Ron Nossaman]

Hi Lorlin,

First off, either a 6.9 mm, or 7.1 mm pin will turn smoother, less jumpy,
than a 2/0 of similar thread cut because the smaller diameter pin will twist
in the block more (at any given torque reading) before the bottom of the pin
moves. You get a lower friction gradient. I know that's not what you asked,
but you need to be aware of the effect if you are trying to compare feel
between different pin/drilling combinations.

I seem to remember that the recommended drill size for Falconwood is
something like 0.009" under pin size. Is that right? A 7.1mm pin is 0.2795,
and an 'I' bit is 0.272", for a difference of 0.0075". Ought to work without
being overly tight. I'm not surprised the 6.9mm pin was too loose, with a
hole drilled 0.0003" undersize. %-) Also, what length pin are you using?
Greg said he used 2 1/4" (or was it 2 3/8"?) length pins in everything
because he felt it gave him more uniform results. If you are driving a 2
1/2" pin, you will get considerably more torque than from one of 2 1/4", all
other things being equal. 

I use Delignit, and drill a 6.8mm (0.2677"), or 17/64" (0.2656") hole for
2/0 x 2 1/2" pins with good results. The initial torque is pretty high, but
the settle in quite well by about the third tuning. I also double drill:
1/4" on the first pass to take the bulk of the material out of the hole,
followed by a second pass to ream the hole to finished size. With this
method, I have to pay little attention to feed speeds because the final pass
is such a light cut.   

If you can't find a combination of pin/drill/technique/torque you like with
the Falconwood, I'd suggest dropping back to a less dense block until you
find one you can live with. With blocks as dense as these (Delignit
included, though not to the same degree), you have little margin for error.
The stuff has very little 'spring back' after compression, so you will tend
to end up with either a very tight, or unacceptably loose pin. That's why
Greg chose the combination he did. If you are going to use these blocks, fit
the pins tighter than you'd really like, and get used to it.

Someone else will, naturally, have entirely different opinions. <G>

Ron




 

At 08:02 AM 9/22/98 GMT, you wrote:
>To: List
>
>I am having a S&S L fitted with a Falconwood Pinblock. I usually install my
>own hardrock maple.
>and am accustomed to drilling them. Some where I recall seeing a discussion
>on drilling and pinning "unforgiving multi-laminated pinblocks".
>
> I attended a Central Western PTG convention in Wichita, KS this year.  There
>Greg Hulme said, in his rebuilding class, that Yamaha 7.1mm pins work well
>when drilled with a letter "I" bit.  Greg said that the difference between
>Yamaha pins and German pins is that the "roughness" of the thread is felt
>when turning the German pins counterclockwise, the Yamaha pins have no
>roughness feeling.  The theory  was  Yamaha pins won't jump.  They are also
>as consistent in diameter as the German pins. 
>
>I am experimenting now to get ready for drilling the Falconwood pinblock.  I
>got samples of  the Yamaha pins and found them felt even rougher in one
>direction that the German pins.  I drilled a Falconwood sample at 940 RPM
>with the "I" bit at about a 9 second drill penetration time.  The pin was so
>tight It took off the tuning hammer tip. I tried the 6.9mm pin with the same
>bit,  too loose. I respect Greg Hulme as a rebuilder and therefore feel the
>fault lies in my approach. 
>
>Any suggestions/case histories/ recollections of journal discussions on this
>subject?
>
>Thanks very much!
>
>Lorlin B, RPT
>ISU Music Dept.
>515-274-5940
>
>
 Ron