Grand Knuckles

[Newton Hunt]

I have tried 'bolstering' knuckles a number of times with different
materials and have never been pleased with the results.  They turn out
so uneven it is difficult to regulate and impossible to get consistent
touch from note to note.

Whenever encountering a piano thay has medium to low quality factory
parts there is but one choice and that is to replace the shanks and
the hammers.

You can try replacing the full set of knuckles which can help this
situation but you still have the problem of lower quality wood and
felt parts compared to what is available today.

In a high wear situation like a teachers piano the weakest link in the
action performance will be the lowest quality or most worn parts.

To save time you can get the hammers prehung by Brooks Ltd. by either
sending them sample shanks and hammers or calling or faxing
specifications.

I am familiar with the instrument you mention.  I have worked on three
from that era and would suggest the following.

Check the capo bar at the middle section to tenor break.  The line
representing that of the agraffes and the capo bearing point should be
a continuos curve.  On some of those pianos the capo bar was moved
toward the bridge in line with the middle section ross brace such that
the speaking length is shortened.  This is a major defect in design
and execution of the plate.  If there is an obvious tonal change
between these to sections then you have this problem.  What has to be
done is to relocate the strike line of the bottom of the tenor
section, by ear and by measurement for best tone.  The backchecks will
have to be moved back and very likely have to have a notch cut into
the back of them to clear the sostenuto bar.  Check this out
carefully.

I have also found that many hammer sets were over stricking causing
further tonal problems.

Measure from the keybed to the underside of the strings at the ends of
each section and carefully measure the keybed to hammer shank center
pin at each end of the action, subtract the latter from the former and
you have the proper bore specifications for that piano.  If the hammer
center pins vary more than .0625" (1/16") then you may have to vary
the bore distance.  If the section ends vary then you may wish to have
the hammers bored accordingly (more than .125" from section end to
section end.

Knabe's design, unlike Mason & Hamlin, calls for the hammers to be
glued on at 90 degrees to the shank.  If this is not the case on this
piano then you will need to make allowances for correcting this
problem.

Measure the the angle of the bass and middle section strings to the
stretcher to determine the bore angle.

Carefully measure the distance from the hammer shank center pin to the
drawn center line of the hammer molding at each section end.

Measure the distance from center pin to knuckle center line.

Measure from flange end to screw hole center to center pin hole.

Te last measurements assure you of getting the proper replacement
shanks.

Call, send or fax these numbers to Brooks, Ltd and they will send you
back a set of shanks and hammers glued up and ready to install.  Fast,
easy and convenient and the teachers piano is down the least amount of
time possible.

Durability, consistency ease of regulation and customer satisfaction
will be greatly enhanced.

Have a great week.

		Newton