Drill bit size for #1 gauge tuning pins

[Ron Nossaman]

>   I don't see how a 5/16 cap is doing all the work & hey It still tunes 
> like a 1/4 sawn maple block.

So does the multi-lam, with the cap. The cap takes the load and supplies 
most of the torque resistance. Look at the density of that 15/32" Delignit 
bridge capping material, compared to Delignit pinblock stock, quarter sawn 
maple blocks, or the rotary cut multi-lam. That stuff's dense! If you drive 
a pin into the assembly through a hole sized for the block underneath, it 
will be a WHOLE LOT tighter than without the capping. Sizing the hole 
closer to what you would use with Delignit alone puts the torque closer to 
where you'd want it for a new block, at least where I want it, with nary a 
crack or pop anywhere.


>  What the cap does  IMO is to keep the pin from mushing out the hole over 
> time & seems to act like a nice tight bearing surface for the pin to turn 
> against.  I've used it as thin as a 1/4 inch & like the results. Hey its 
> worked for Yamaha for 45 years & I think everbody like the way those tune.

Yes, it does that, and the soft maple blocks surely do need that support. 
Using the bridge capping full thickness is a different bear than what 
Yamaha does though. I thought of doing this as a means to get both the 
support, and the feel without the drawbacks of either Delignit, or the soft 
quarter sawn blocks. Being able to do it with the cheaper multi-lam block 
was a bonus.


>   The cheap blocks which are rotary cut & flat sawn as a result  may not 
> hold up that well in some climates Like yours partner?. Or the nevada 
> desert & other dry places.

That's no different from the quarter sawn blocks. They self destruct under 
extreme conditions too. The only disasters I've seen from the cheap blocks 
(assuming competent installation in the first place) were in school systems 
with steam heat where the RH% went from over 75% in the summer, to under 
20% in the winter. In fact, that's one of the reasons I originally went to 
Delignit many years ago. The multi-lams tended to be snappy if they were 
drilled tight enough to hold up under climatic abuse. The Delignit will do 
that too, but the double drilling helps that, which is one of the reasons I 
developed the process. The problem (among other things) is that the bottom 
of the hole is as tight as the top of the hole, and it doesn't need to be. 
There's almost no string induced stress on the pin and block at the bottom 
of the pin, so the bottom half of the block serves mostly to keep the pin 
pointed in the right direction, and supply the snap of jumpy pins when it 
gets the chance. A low density block capped with the Delignit bridge 
capping stock changes the torque gradient down the pin, and lets the bottom 
catch up with the top without kicking the top loose and snapping. Again, 
this works with both the $75, and the $315 low density block. It is my 
expectation that, since the majority of the tension and leverage is 
supported by the much tougher capping, the underlying block is under 
considerably less load than if it were doing all the work itself, and won't 
deteriorate nearly as badly or as quickly under climate extremes as a 
result. Lower compression levels ought to mean less compression set. That's 
the theory, anyway, and that makes the expensive block a waste of money and 
good wood. I like it so far, but I'll let you know in 20 years or so how it 
works out in long term practice.

Ron N