[pianotech] S&S K(52) Restoration

[Ron Nossaman]

On 5/21/2012 12:09 AM, Gene Nelson wrote:
> So on an upright you can remove some structural material probably up
> to the point where you are getting into the pin block??? - allowing a
> bit longer rib up there so you are not forced to locate the bridge at
> the point on the rib where tapering begins Am I seeing this design
> feature accurately??

The bridge treble location, at least the speaking length pin row, is 
interdependent with the plate location, and where the action needs to 
go. Or in a design protocol, they are all located from the "first line 
drawn" on the design. The strike line. So you probably don't have a lot 
of options in a retrofit to relocate the treble bridge. In the vertical, 
you do have more options to redefine the inner rim up there, so that's 
what you work with. Rib feathering is cut to accommodate the bridge 
location. In grands, it's very asymmetrical because the bridge can't be 
centered on the rib. In verticals it more likely can, though the last 
rib in both cases can be made about the same length.

In grands, you only have around 25mm to play with between the inside of 
the inner rim (at the belly rail) and front edge of the bridge 
footprint. That's why the pin rows are off center and the front edge 
undercut. It's to get the bridge footprint as far away as possible from 
the belly rail without cutting the undercut beyond the front pin row and 
making what amounts to a cantilever.

Same intent, same rules, different restrictions to work around.

Ron N