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Orchestrelle, Chapter 13.1
Rebuilding the Æolian Orchestrelle
58-Note Player Reed Organ, 1912 Model "W"
by Richard Vance
Copyright (C) 2000 by Richard Z. Vance
rev. A, 18 November 2000

Chapter 13.1 - Fixing the Touch Box

    If your organ has not been messed with, you can skip this chapter, which deals with repairing the damage done by someone in the past.  I think it was originally configured thus.  When the key lever pushes the pallet stick up, the pallet lifts and admits wind to the primary pouch circuit.  The 9/64" pallet stick rides in a hole between the bottom of the box, and a detachable rail below.  The central part of this hole is larger, about 3/16" diameter.  To minimize leaks and noise from wind escaping through the stick hole, a tiny pouch leather washer is glued to the stick, and rides up and down the enlarged part of the hole as a seal.

     A previous owner removed the player parts, and wanted to convert the organ to "single action", with no primary valves.  The touch box was tubed directly to the big secondary pouches.  This might have worked, but it presented a dilemma.  The bleeds are in the primary circuit, and there is no way for the wind to escape from the secondary pouch at the end of a note, except by slowly seeping out through the porous pouch leather.  That system would have been quick enough to inflate the secondary pouch when the pallet was lifted, but there would be a lag when the note ended.  So the fixer made a path to allow the circuit to deflate properly.  A little groove was cut between the tube hole and the pallet stick hole.  Cut is not the right word; the groove was burned in the wood with a soldering iron or a wood-burning set (a poker-work tool, for you British Orchestrelle fans).  To increase the capacity of the escape path, the pallet sticks were pulled out of their holes, stripping off the leather washer.  Only a few old washers lurking in the box, and the glue ring on the stick where they were attached, even gave me a clue that they should be there.  Also, the pallet sticks were scraped smaller where they passed through the small part of the holes, and then lubed with graphite and grease, so they would move smoothly again after being so roughened.    The first picture is self explanatory, except for the gray square at the top of the box.  That is a thick strip of soft red felt, to prevent the pallet from going too high, and popping off its guide wires under vigorous, rapid play.

    I had to do three things to put this right.  First the spurious path had to be plugged.  The grooved area was carefully drilled out with a 1/4" Forstner bit.  A 1/4" plug cutter was use to make plugs for these holes.  Basswood was selected, because I had a piece, and I figured it was so soft that the plug could be easily trimmed level with the sating surface.

    After the plugs were glued in, the channel was reamed out with a hand held drill, and relined with shellac, using a pipe cleaner.

     The plugs were carefully trimmed down with a razor blade.  Then the whole seating surface was carefully smoothed by scraping with the edge of a single edge blade.  All the front row of pallet guide pins had to be pulled out to gain access for this, then all put back in.

    Next, I had to make all new sticks.  I discovered by arduous net search, that no one made 9/64" doweling.  So I had to make my own, by chucking a short piece of bigger stock in the drill press, and spinning it down through a steel plate with successively smaller holes (a drill sizing plate with all the 64ths).  Only very sound and straight doweling can stand this treatment without splitting or spalling.  Commercial 3/16" dowels were too uneven and coarse to work very well.  Only piano hammer shanks, made of much better quality stock, usually worked.  I went through a whole sack of 100 shanks to get the 58 pieces (plus a few spares) that I needed.  But the sticks that did make it through the reduction process were all perfectly straight grained and mirror smooth. What a pain.

    Finally, something had to be done about the seals.  I had no way to accurately punch tiny washers out of pouch leather.  So instead, I made the seals fixed on the board.  The lower rail was removed and a strip of pouch leather was glued across ts whole length.  At every hole, the leather was pushed in with a pencil eraser, like dipping tiny pouches.  I found that one of the smallest nozzles on a rotary hand punch just fit into the 9/64"-plus hole in the rail.  With this, small holes, about 7/64" diameter, were punched in the exact center of the leather.  The pallet sticks poked through this hole easily, stretching it a little bit, and the sticks moved smoothly through the opening.  Under test, this seal proved amazingly effective.  Although pouch leather is flimsy, the effective area tending to blow air by it, is also very small over the tiny area of the seal.
 
 

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