Larry Toto wrote:

> I wish to increase the touch weight of an upright player.  Am
> I asking for trouble by replacing the hammer return springs with
> (Schaff) medium or heavy gauge springs?  I suspect that the
> pneumatics can handle the added load easily enough, but will the
> repetition rate be affected?

Definitely install new hammer return springs.  I do in all rebuilds and
most refurbish jobs.  It is the fastest way to return snap to the feel
of the upright piano.  It will improve repetition greatly and it will
help get rid of that sloppy old piano action feel when you play by
hand.

When you do this be sure to drill a tiny hole (spring sized) about
1/8" above the one that is there.  Use the cut on the back side of the
spring rail and clamp a jig on the drill press to get the row of new
holes straight.  Some companies made these holes from the factory, but
most of them used a machine to crimp the spring into the wood.

When you remove the old springs, this crimp is shot so some other
method to hold the spring must be used. The new spring tail will go
through the original hole and then curve back through the new hole.
You can pull the tail tight with a pair of needle nose pliers.  Grip
it and the turn the pliers to one side to lever the spring tail to pull
the loop out of the other side.  Snip off cleanly and you have the
spring installed.

The coils MUST be up against the wood on two sides just like the
originals are.  If you leave some tail sticking out between the wood
and the coil that tail will bend and take out all your spring strength.
Finally you use pliers to line up all the springs.  Some will need to
be twisted to all point parallel to each other and perpendicular to the
rail.  You will notice when you reinstall the rail, the new springs
stick way out like the old ones no longer did.

These springs are brass and get very weak after fifty years or so of
use.  Only new ones can solve the problem.  The new ones sometimes must
be recurved on the butt end to shorten them.  I sometimes make a jig to
curve and cut them off before I install them using the old springs as a
guide to make the jig.

> Currently, the highest repetition rate is notably (no pun intended)
< slower with the soft pedal applied.

The reason for this is the fact that with the soft pedal on there is
suddenly lost motion between the top of the jack and the leather of the
hammer butt.  The later Ampico grands used the lost motion pneumatic to
move the stack capstans up so there would be no lost motion.  In a
grand you may notice the keys move up in back just like the upright
butts do in an upright.  If you could move the stack up with the hammer
butts and remove the lost motion repetition would not be impaired.

You might improve repetition by lessening the amount the soft pedal
moves the hammer rail.  Some companies do this with a small block of
hard hammer felt trimming glued to the hammer rail felt that hits the
action bracket to stop the movement.  Some companies use wood blocks
with thin felt on one side to do the same thing.  This block is often
positioned down at the pedal rod end (bass) of the hammer rail.

By the way if anyone has need of hammer felt trimmings, you can write
Ronsen piano hammer with a small check for packing and postage, usually
about $10-15 and they will send you a box of felt hammer trimmings that
they otherwise throw away but will last you a decade.  I use it all the
time as upright hammer rail props or bumpers for this or that.

There are many places to use this felt.  You can also slice it up and
use it for wet wedges to remove key bushings.  It must be cut with a
very sharp felt knife as sold by piano supply or Tandy leather.

D. L. Bullock    the Piano World    St. Louis