Bridge pin angles

[Phillip Ford]

>
>Sure, if we were factories, and talking about boards, I agree. As 
>rebuiders, we don't get to put what we consider to be our best 
>soundboards in every piano. More often, the original board is there, 
>and we have to make the best of what we have. Even with a new board, 
>if we aren't allowed to make changes to the design, we will very 
>possibly be setting the plate for zero bearing on a cantilevered 
>bass bridge. With an original board, we can't say what the bearing 
>will be next year, and a sampling of posts to this list indicate 
>that the majority of pianos being rebuilt are not getting new 
>soundboards, and of those that are, very few are getting rib 
>supported boards. So we (collectively) can't assume bearing, and the 
>rebuilt pianos I've looked at through the years indicate that to be 
>the case.

OK.  Point taken.

>
>
>>Establishing a minimum and building to it are two different things. 
>>I'd like to know what the minimums are.  If what is needed for the 
>>termination to function properly with a properly set up and 
>>properly functioning board is 2 degrees of side bearing and a 
>>bridge pin angle of 5 degrees then I don't want to put on 10 
>>degrees of side bearing and a 20 degree pin angle just to be safe, 
>>because there are negative consequences for doing so, in the form 
>>of poorer rendering and increased bridge cap wear.
>>
>>Phil F
>
>If the minimum is 2° offset, and 5° pin angle, and you don't want to 
>go to 10° and 20°, what would you chose as a suitable set of angles, 
>and why?
>
>Then, by what criteria, and under what variations of available 
>materials and climate conditions would you establish these minimums?
>
>Ron N

<G>  I knew you were going to ask that.  Two good questions for which 
I don't have answers.  So, in the meantime I guess I'd better use 10 
deg. and 20 deg. until I can come up with some answers.

Phil F