Rebuilding Chein PianoLodeon
By Mike Kitner 

John Kleinbauer wrote asking how the Chein PianoLodeon works.  I've
had a few of those apart and they are very unconventional, like nothing
else I've ever seen.

The PianoLodeon is a vacuum-driven system, the vacuum being supplied
by a small electric motor-driven fan.  The same motor turns the roll
via a worm and worm gear arrangement and a small rubber belt.

The trackerbar is moulded into the cabinet and connects to what I would
call the "valves" through rubber tubes.  The valve is a sort of plastic
see-saw.  One end of the see-saw is a paddle covering an opening in the
vacuum box, the other end is positioned underneath the note inlet which
is connected to the tracker bar by one of the rubber tubes.

When a hole in the trackerbar opens, air rushes down to the inlet and
blows against the end of the see-saw depressing that end and causing
the other end to rise and allow air to rush into the opening under it.

This opening communicates with what I'll call the "striker vane" which
is another plastic paddle.  This paddle moves through a semicircular
chamber (there being of course one vane and chamber for each note) with
vacuum applied to the underside of the vane.  The vane really doesn't
touch the sides of the chamber, its just close.

It reminds me of the vacuum operated windshield-wiper motors they used
on older cars.  The opposite end of each vane can flip a plastic hammer
against a tone rod when it is activated.  The system works okay but it
clatters and rattles, as you know if you've ever heard a PianoLodeon
working.

There are actually some "rebuilding tips" I can impart if you're
interested.  The whole thing comes apart pretty easily.  The little
see-saw valves are right under the keys and fuzz and dirt can cause
them to leak and hang up.  You have to pull the vacuum box out of the
case.  You'll find that you can "pop" the valves and the vanes out of
their fulcrums.  Do that, clean everything and graphite the fulcrums
before reinstalling them.  Usually the trackerbar tubing is splitting
so replace that.

You can get an O-ring that will work as a replacement for the drive
belt.  Disassemble and clean the motor and lube the bearings.  There
is a felt ring that provides an air seal between the blower fan and
the player box.  Make sure that's OK or you'll have a big vacuum leak
there.

There's a piece of foam rubber under the keys and another above them
at the "fall board".  That's usually bad and you can replace it with
a strip of piano butt felt.  Put on a new power cord.  I can't think
of anything else.

You might want to attempt tuning.  It can be done!  I have noticed
that the arranger of the music seems to have taken the overtone
structure of those tone bars into account and the arrangements some-
times don't make sense if played on a piano but on the PianoLodeon
they are recognizable.

Mike Kitner


 
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