[pianotech] Brumbach Rebuild

[Jon Page]

Start with rectifying known coefficients.
String height minus hammer bore = hammer center height (HCH);
more or less depending on hammer pitch and string angles
to achieve a 90 degree contact.

Wippen center height works well if it is 2.5" below HCH.

Coordinate this with action spread such that the knuckle core aligns
with the jack center at rest (90 degrees to the shank if possible).
Read Bob Hopf's article on Action Elevations.

 From the placement of the drop screw, I'd say that the spread is too short
which accounts for the capstan on the rear of the cushion and the contact
position of the tender appears to be on the front side of the let off button.

Once you get these in sync you can decide if the capstan has to move to
get it all to regulate properly such that the jack sufficiently 
clears the knuckle
or does not become bound against the rep stop felt when the key is fully
depressed. Then you can decide on the heel height to intersect the ML.

It's a cinch.
-- 

Regards,

Jon Page