I have been working with a partially "rebuilt" Steinway M that has been a dissapointment. There is quite a bit of touch irregularity, especially in the low tenor and bass with differences in aftertouch despite my key level, dip and regulation. Today, while trying to figure out why I noticed that the whippen line was quite irregular, the problem seems to be at the whippen rail. This leads to different jack settings with irregular jack to knuckle positions.
How common is this and how much attention do you rebuilders typically give to whippen lines?
Look carefully at the alignment of the whippen flanges, or at the line of the balancers. Both show an irregular line, the cause being how the whippen flanges seat and change the position of the whippen, then this affects the relationship of the jacks to the knuckles. You probably need to zoom in on the flange line.
Yes, I see what you're talking about when I zoom in. I've never had this problem before. I can't even figure out how it could occur (unless the rail is split on the underside and now creating random places where the flanges won't fit).
Are these factory parts or aftermarket? What is causing the random tipping of the flanges?
Peter Grey Piano Doctor
this is a common problem on Steinway grands from the CBS era. The holes in the rail are drilled on either side of the rosette center. Fortunately Steinway figured out a way to stop this happening in the late 1980s. Ed McMorrow describes a solution to this problem in his book The Educated Piano. He describes a solution for the hammer rail but it works on the repetition rail as well.
I see variations in the spacing between the whippen flanges-some are close to neighbors and others are not. You should look at the toes of the jacks and attempt to travel the whippens so the toes are centering on the letoff buttons. If you do not find travel paper on the flanges the problem may be variations in the thickness and widths of the flanges. I would measure the width and the thickness of some of the better fits agains the miss-fits. The big question is what brand are these ? Are the hammers/shanks/flanges new ? what condition are the rails in ? are screw holes enlarged ?
This could be a long-shot answer to the problem, but we just finished regulating a re-built 1878 85-note Steinway A-1. The set of wippens have "TREBLE" stamped on the top 15 wippens or so. If the wippens on your piano appear to have flanges of different lengths it could be possible that the previous re-builder didn't notice this detail.