I will describe my prototype as best as I can.

I start out with a 1X4 popular board. this board is set into the piano
and with a square, every other sticker position is marked, (for a two
tier) or every third one (three tier).  I construct three tiers for
the large empty players, two tiers for a narrow regular upright that
never had a player.

Next, I have a "jig" that sets on the board to mark the valve positions,
all the way across. Where this line and the sticker line intersect, I
use my drill press and drill a 3/4 inch hole all the way through the
board. This is the valve chamber. I then stand the board on end and
drill the 3/8 inch pneumatic feed holes from the long side of the
board, into the valve chambers. the open holes on the end is closed
off with 3/8 inch wooden dowels and sanded smooth. Now I have a internal
channel.

Next, again using jigs, I rip some thin strips and glue them on the
bottom of the main board to form a windway. Next I put a pouch board
on this, install screws and sand everything, including the pencil marks
away.

Flipping the pouch side up, I then mask off the outside valve holes and
pour the whole thing full of phenoseal, let it set for a while, and
then drip dry.  This really makes the stack tight! The pouch board is
reattached, and sanding sealer and flat black paint is applied.

The pouch board at this point has not had the pouch wells drilled yet.
The pouch board now is removed.  Firestick antenna company makes some
nylon antenna washers with a large shoulder.  I epoxy these into the
bottom of the 3/4 inch hole and viola! a valve seat.  It happens to
have a 3/8 inch ID [internal diameter]. I can get these by the thousands!

Once the lower seats are in place, I put the pouch board back on. Using
a 3/8 inch Forstner bit by hand, I run this through the lower seat by
hand, carefully "marking" the pouch board. Then the pouch board is
taken back off, the wells drilled, and the bleeds and input channel
added.  The bleeds are a real pain though!  Now the pouch board is
sealed and the pouches are installed.

The valves are made from a 5/8 inch X 1/16 inch fibre washer, patent
leather on the lower side, calf on the outside, (this seemed to work
the best). My prototype used standard type stems and guides, but I am
sure the 3/8 inch fluted stems would work also and be lower cost to
produce.

Once the valves are installed and the stems sized in relation to the
pouch, pneumatics are then made and hot glued on to the deck.  Fingers
are added.  You have the choice of a poppet rail or you could also
install abstracts on the stickers. The pneumatics have their own
adjustable stop.

I plan to use a regular upright to "player-pianorize" uprights, which
are plentiful, and many are excellent pianos _when restored_.  The two
tier stack is only 6 inch deep by 5 inch high.  If I start selling
'converted' uprights, suffice it to say that  without exception the
pianos will get new strings and pins, and be brought back to top
condition before it would be fitted with the player action!

Right now I am shooting for the standard 88 note type format. The piano
will have the full compass of 88 pneumatics and valves.

Here are a few thoughts on modifying a standard upright case for player
use and making the conversion look factory.

On a regular old upright, (non player), the folding lid could be removed
from the fallboard, and the fallboard thinned with a table saw to create
a "compartment".  I know it will vary from piano to piano.  I need a
compartment at least 5 inches deep by 5 inches high.  Six inches deep
would be comfortable margins.

The capstans could also be relocated at the very back of the key, and
the keyboard slid slightly forward, and the keyslip thinned somewhat.
On some uprights you can gain about 3/4 inch this way.

To gain clearance in the non player upright  for a spoolbox two things
could be done.  First, a spoolbox could be mounted up over the hammer
line (like an old Kimball) the only down side to that would be the
tracker bar tubing would be draped all over the front of the piano
action. it would of course work, but would probably give the tuner a
scare and look tacky.

The second and (I think) the best way would be to move the upper
pilasters and front board forward by about 2 inch on the music shelf,
and install the spoolbox in the "official" location. some veneered
strips should be worked into the cabinet on the sides, in such a way
to make this modification look like it belongs, and the front panel
can have spoolbox doors installed.  With skill, it would be quite
handsome.  If this is done,  the area below the keybed and bottom board
should extended as well, so that the case doesn't look out of balance
in relation with the top.  On the bottom, the legs could easily be
notched to move the pedal board forward, and a new bottom installed.
This would also increase room for just about any pump you would want
to use.

Best Regards
Andy & Chris Taylor

"The Lone Arranger"
Tempola Music Rolls
"Taylor Made" Just For You
http://home.swbell.net/tempola/index.html