Eliyahu Shahar wrote in 030428 MMDigest:

> I've been working up an idea for converting the mechanism to
> a Vorsetzer, building a cabinet and arranging the parts to play my
> piano.  The idea here is to make the cabinet as small as possible and
> attractive so as not to attract extra attention while it's not playing;
> I think I can get away with that.

I know of four such productions, at least enough to have rested my hand
on them:

 - Denis Condon's built-from-scratch hi-tech Vorsetzer, in
   Sydney, Australia;
 - Peter Davis's conversion of a 65/88 note Pianola;
 - Gordon Iles's special robot in the keeping of Gerald Stonehill, and
 - the still ongoing Pianola Institute conversion of a late Hupfeld
   73/88 note Phonola.

A common feature is that they're not small.  A good-sized set of
pneumatics is essential if you are going to have any chance of waking
up a big grand in a large concert hall.  It is common for Duo-Art
pushups, indeed, not quite to manage this, because the power which
satisfies in trials in even a spacious domestic setting will not do so
there.  The Hupfeld conversion has shown promise by not playing softly
enough on its first outing.

If the small size is important, I'd start again with solenoids.  They
will probably need forced cooling, too, if you want to cover pieces
like the four-hand version of Dohnanyi's concerto.  You can get that
kind of strike out of a neat little 6-volt solenoid offered 150 volts
for a short while.  But filling the recital room with shellac smoke is
not my idea of authenticity.

Faced with translating Duo-Art accordion travel to electrical power,
I suspect I'd cheat and use two accordions with dampers to replicate
the original lag.  Then use optical sensors to put input into a
processor using a look-up table you could tweak for the piano and the
place.

Now that I think about it, there are certain traditional Duo-Art grands
I can think of which could benefit from the last-named refinement.
If I slide my hand artlessly under the corner here, no roll can be
coded too soft ...

Another approach if small size is essential is to have a roll
player which generates a wholly digital piano and hall.  Front end
traditional, then a pouch board like an organ's and then the
electronics of something a bit better than a Clavinova.  Has this been
discussed here ?  One would have tremendous promise for apartments.

Dan Wilson, London