Birdseye Maple

[Ron Nossaman]

Hi Jim,

I've got to agree with you on the first observation. It's sad to waste
"pretty". There's little enough of it to go around, and too few IMHO, who
are equipped to appreciate it. My condolences.

Jumpy pins - nah. Pins get jumpy when the coefficient of friction
(static/sliding friction) between the pin and the block is large. A greasy
smooth threaded tuning pin in just about any block is a good example. The
static friction can be quite high (determined by the block density and hole
size the pin is driven into), but the sliding friction is quite low
comparatively. Once you torque the top of the pin enough to get the bottom
moving, the bottom snaps around quickly (low sliding friction) and catches
up with the top and stops, where it's once again held by the high static
friction and ready to do it all again when you try to move it further. Cut
thread pins aren't as jumpy because the threads carry enough wood fiber to
increase the sliding friction to more nearly the same as the static friction
- a low friction coefficient. The birdseye wouldn't do anything to lower the
sliding friction any more than any other layer in the block. As far as the
grain going all over the place, look at a hole drilled into the side (not
the end) of any piece of wood. You are looking at over 90 percent end grain,
ranging in cut angle from 90 degrees to zero as you go around the side of
the hole. With the birdseye, the distribution is just a little different,
but it won't make any difference in the feel of the pin in the block.    

Too bad we can't unsaw used lumber to re-use the "pretty" in a more
appropriate place.

Ron

>et al;
> I was planing down some scrap pinblock for a project and noticed some of the
>most beautiful birdseye maple that I have ever seen in one, actually two, of
>the layers.  As I was planing away, crying the whole time that I had to lose
>this stuff, I started thinking about jumpy tuning pins.
>  Question:
> Is it possible that birdseye in several plies of a pinblock could
>cause/contribute to "jumpy" pins ?  Particularly if there is more than one ply
>that has the birdseye?  With the grain going around all confused like that,
>could  birdseye contribute to "jumpy" pins?
>Just a weird thought that ran through my head :-)
>Jim Bryant (FL)
>


 Ron Nossaman