those pesky nose bolts

[Ron Nossaman]

Gene Nelson wrote:
> Just thinking if anyone has a technique that will consistently get the 
> nose bolts dead center in the hole in the new soundboard.
> Seems that getting the plate to case alignment perfect (same as it was 
> before tear down) after the new block was epoxied in the case, then 
> transferring nose bolt hole locations - marking and drilling the board 
> was just not enough.
> Out of 7 - 3 were dead center, 2 were ok, 1 almost touching the edge of 
> the hole in the board and 1 will not go in without elongating the hole 
> in the board.
> There is something missing for me as it is difficult to figure a way to 
> include the nose bolt mounting holes in the case into the process. 
> Transferring nose bolt locations to the new board seemed fairly straight 
> forward but it was assumed that those mounting holes below would cooperate.
> It was obvious that the nose bolts were not drilled perfectly virticle 
> but they fit into the plate nicely prior to tear down. I did not think 
> this was an issue.
> Thanks for any thoughts and comments.
> Gene
>  

At tear down, I drill two locator holes through the plate, 
into the rim. One in the treble, and one in the tail. I use 
these holes to index plate and board when I locate bridges, to 
index the soundboard when I locate nose bolt holes, and when I 
glue it in. Again with the plate to locate the pinblock. I 
find I need the soundboard assembly dried down to the same 
level for everything from ribbing to final installation unless 
I want surprises along the way. With the nose bolts out, I 
drill the pilot hole they're in clear through the bottom of 
the beams. Then, locating the appropriately dried soundboard 
on the two pins and clamping the board down onto the rim in a 
few places, I transfer punch the nose bolt hole locations on 
the soundboard from underneath. This works better for me than 
anything else I've tried, and I still don't get perfect 
centering. If there's a better way that doesn't involve yet 
another level of psychosis or the ability to slide drilled 
holes to other locations, I'd like to hear it too. Actually, 
If there's a way to slide drilled holes, that's the one I want 
to hear about first.
Ron N