Hi All, For those who may be interested, I've just uploaded the series
of pictures that I took while working on the Elepian player piano last
week. I installed links below each picture to three other size pictures
of increasing quality for those who want to see more details. See:
http://www.player-care.com/elepian-pictures.html
There were two major problems and one minor problem with the piano that
I was able to successfully repair for the long term. They involved the
tubing, the air motor, and the stack cut-out switch (pneumatic). In
order of their effect on the player system, the worst problem was the
air motor. Second was the tubing, and third was the stack cut-out
switch, which only needed to be realigned to achieve a good seal.
As can be seen in a couple of the pictures, the tubing leading to the
upper half of the stack is bent over, pinching off the signal from the
trackerbar. The solution to this problem was the replacement of the
straight nipples with elbows. However, the real culprit was the air
motor.
It's almost hard to believe that the air motor, which is only 25 years
old, was leaking so badly that nothing else requiring vacuum would
operate. After determining the severity of the leakage, dismantling
the air motor, and giving it a quick visual inspection, I could see
that the sliding valves weren't making good contact with the block
(or the trunk). What I didn't expect was the amount of block warpage.
Literally speaking, it was concave, like a saucer.
As I started sanding the block, I quickly realized that it wasn't going
to be an easy job. So, I modified my normal S.O.P. (standard operating
procedure), and started with 80 grit sandpaper. The pictures I took,
which graphically show the warpage, were shot at intervals of
approximately 30-40 passes across the sandpaper. After some 200 passes
across the 80 grit paper, I started using finer paper (120, 180, 240,
400) until the block was clean and flat.
If you've followed along and are still reading this posting, perhaps
you might be wondering how the block got so warped. I know I was...
And what's a bit more puzzling is the fact that the internal air
channel was air-tight, the bellows were almost 100% air-tight (tiny
leaks at the corners), and the sliding valves needed very little
attention. I have a couple of ideas as to what might have caused the
warpage, but I'm curious to hear what others think. If you look
closely at the block, it's made out of only two pieces of wood.
The valve surface is mahogany and the base is poplar.
If you have any ideas, please share them with the group.
By the way, I'm currently working on a web page with more information
about the Elepian player piano. One thing I didn't expect is that it
has a touch-sensitive keyboard. However, I could find no 'reeds' or
'bars' like in the Wurlitzer and Fender Rhodes instruments made in the
same era as the Elepian. Although I'm not 100% certain, it appeared
to me that action for each note didn't strike anything. However, there
are these curved pieces of plastic that move past a circuit board,
which gave me the impression that the board 'read' the velocity of
the strike and converted it to the amplitude of the note. Very
interesting...
Musically,
John A Tuttle
Player-Care.com
Brick, New Jersey, USA
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