QRS Music Technologies PMII Installation Manual - Installa On Procedure
Installa on Procedure
21
July 2013
Installing the Sustain Pedal Solenoid ‐ Grand...
You can now turn your a en on to the installa on of the sustain pedal solenoid assembly.
This procedure is not required when sustain pedal is not installed.
Because there is a certain amount of varia on in the architecture of grand pianos, you will probably have to custom‐tailor the following direc ons to
suit the mechanical dimensions of the par cular instrument you are working on.
The key elements to focus on here include the sustain pedal lyre rod's upward projec on onto the keybed immediately above it, the loca on of the
large hole through which the original sustain pedal pitman dowel projected to reach its corresponding hole in the wooden or aluminum damper tray
(which li s all of the piano's dampers simultaneously), and the rearmost OUTSIDE ver cal wall of the keyboard compartment, called "the belly rail."
The proper installa on of the sustain pedal solenoid assembly takes into account the dimensional rela onships of these three elements.
In addi on to providing for both the manual and automa c opera on of the piano's dampers, you want to give the sustain pedal solenoid as much
mechanical advantage as possible in order to minimize the power required to ac vate it. Despite the excellent design of the sustain pedal solenoid
assembly, its long term opera on depends upon your skill in loca ng the various leverage‐points which enable it to func on both manually and auto‐
ma cally.
Op mally, the sustain pedal solenoid assembly will be mounted on the belly‐rail immediately behind the sustain pitman dowel which formerly con‐
nected the old trapwork lever's far end to the damper tray in the keyboard compartment. This arrangement provides the shortest distance between
the sustain pedal solenoid assembly's lever‐arm and the load imposed by the damper tray through the pitman dowel. Where such a situa on exists,
you will use the four moun ng holes to locate the four #10 x 1" panhead screws used to secure the pedal solenoid to the belly‐rail. If the belly rail is
too close to the pitman dowel, locate the solenoid on a frame member or on an extension a ached to the frame member.
Now, measure the distance from the center of the pedal solenoid's pusher p to the exact center of the damper tray's pitman rod loca on. Sixty per‐
cent (60%) of this distance FROM THE PEDAL SOLENOID'S CENTER (that is, the lion's share of this distance) is the loca on of the fulcrum of the trap‐
work assembly's straight bar. The remaining 40% of this distance becomes the minor por on from the fulcrum to the pitman dowel.