Would anyone be as kind to explain to me how the bell or glockenspiel
on a Bruder organ works?  Upon inspection, it appears that the striking
pneumatics are under pressure and have a return spring which causes the
bells to be struck when the pneumatic is opened to atmosphere.  Anyone
care to help me understand how these type systems operate, or would you
have any "available" suggested reading?

At this time it appears that there is insufficient pressure to inflate
the pneumatics, therefore when it's time for a note to play it can not.

Sam Harris - Greenville, NC
www.PlayerPianoShop.com

 [ When the hole in the paper roll or music book occurs on Mortier
 [ organs (and probably many others), the pneumatic slowly pulls the
 [ beater away from the drum.  After the hole passes by the tracker bar
 [ or the keyframe, a large exhaust valve opens and a spring quickly
 [ accelerates the beater.  If the valve opening is sufficient then
 [ this method insures that the beater speed is relatively unaffected
 [ by variations of supply pressure or suction.  I understand that the
 [ beater travel distance is usually adjusted to make the drum strike
 [ coincide with the pipes sounding.  Altering the beater velocity for
 [ greater or lesser volume, if proper timing is to be maintained,
 [ usually means a lot of fiddling with the spring force and valve
 [ opening.  -- Robbie