Pinblock too low

[BobDavis88@aol.com]

Subj:   Re: Pinblock too low
Date:   09/13/2002
 I responded to this earlier but it only went to Mike, as I pressed "reply" 
rather than "reply all." So, I'll try again....

Mike Spalding writes:

> Then I pulled the action, which did not slide out easily, and saw the 
pinblock 
> hanging 1/4" below the stretcher, and the furrows ploughed (plowed?) by the 
> drop screws.

Mike,

Others have mentioned that the shims might have been left off the shoulders. 
There are other possibilities, most of them bad. Did the other guy use 
pinblock stock that was too thick and just channel over the shoulders to 
obtain the right plate height, leaving the rest of the block hanging down? 
Did he use the right thickness block and channel down only at the shoulders 
in an attempt to "lower the plate" to get more downbearing? Are the hammers 
the wrong bore (too short)? By the way, are the drop screws already backed 
out quite a bit? That might indicate a bore problem. Check the difference 
between the string plane and the height of the shank centers, and compare 
w/the bore.

On the positive side, I like bolstering the knuckles. Think of it as forcing 
the wippen down, away from the drop screw. For the same reason, take a look 
at the leather cushion the drop screw bears against, to see if it's extra 
thick. Maybe you can use a thinner one. That would allow the repetition lever 
to rise a little higher (or the drop screw to chase the cushion down). 

I would not take this on unless my detective nature was certain that I 
understood his thinking AND the original design completely, and maybe not 
even then. Once you undertake to solve the problem, you assume a certain 
amount of liability, and if you are using emergency methods instead of 
following the original design, there is a strong chance you will not be 
solving ALL of the problems he created. If the client is willing to pursue 
the rebuilder legally, you might want to consult with another qualified 
technician, with whom you could share your findings, and who could act as a 
second opinion. If you use stopgap methods, make sure that it is customer 
driven and that they sign off (literally) on the possibility of 
cost/performance compromises.

Remember that where Hero Points reside, Goat Points also lurk.

Good luck,
Bob Davis