Vertical Hammers

[Warren Fisher]

PNOTNR@aol.com wrote:
>
> I would question the economy of replacing the hammers, but not the shanks and
> butts.  I suppose that the butts 'might' be good enough to reuse, but how
> could the hammers be worn out, but not the butts?   Kind of like buying new
> tires for a car, but not having the alignment done.
>
> The question about replacing vertical hammers reminded me that I had meant to
> ask a question earlier about hammer hanging.  The new butts I have to install
> were drilled to receive the hammer shank about 1/8" further forward then the
> position of the hole on the original butts.  The original hammers are 2-1/2"
> from bore to strike point.  To use  replacement hammers with the same bore
> length will not allow me to have the hammers strike at 90* to the string.
>  And the different position of the hole in the new butts makes for a
> different angle of the shank against the hammer rail.  So my new hammers
> don't line up with my guide hammers.
>
> What's the best thing to do here?  Simply use a shorter bore distance?  Plug
> and redrill these butts <gulp>?  Look for other butts closer to the
> originals? (There don't seem to be lots of choices here).  Is the main
> concern to have the hammers strike at 90* at the correct strike point?
>

Gordan,

The strikepoint of often filed hammers will be lower on the strings than
they were new. The last set I replaced were striking almost an eighth
inch lower than originally.  You need to estimate that original strike
line and adjust the shank length and rake to correct for the difference
at the bottom of the shank. All the vertical hammers I've replaced so
far have had 5-10 degrees of downward angle (rake) at rest to compensate
for flexing of the shank on a hard blow.  This means at normal play they
don't strike at exactly 90 degrees.  The most important concern is the
correct strike point on the string, because that causes the most
effective and powerful beginning of the vibration pattern and harmonic
generation for that string!  Just a tiny bit off on either side will
make the note sound muddy.  I'm sure you've noticed that test blows
while tuning don't sound as clear as when you're just playing the note.
It's because the hammer is striking above the strike point! Press fit a
shank into head and butt next to the guide hammer and push it against
the string and hold the guide hammer so its' shank is lined up with the
new hammer shank paralleling the strings.  Sight along the center lines
of the hammers to see if they both point at the string that marks your
strike line.  If not you should be able to see what needs changing!


Good Luck!  Old Technicians' adage "Measure twice; cut once!"

Warren

I surely wouldn't plug and rebore any butts!
--
Warren D. Fisher
fish@communique.net
Registered Piano Technician
Piano Technicians Guild
New Orleans Chapter 701