Hi Dave - Hope this will assist you.

> When the transmission goes into rewind, it begins winding and the
> shifter then slips a tiny amount out of rewind.  This stops the roll
> action and begins a tick, tick, tick as the tips of the pins hit
> without locking in enough to pull the roll.  I have strengthened the
> compass spring but to no avail.

These mystery problems can drive you nuts!  There is only two ways that
this problem can happen.  1: It is getting a signal from the valve and
doing what it is told, or 2: (and this is where I would look first):
the pneumatic that does the shifting is hinge bound slightly, just
enough to act as a spring that will cause it to open after the initial
suction is cut off.  If not hinge bound in the real sense, cloth that
is too heavy or thick will cause the same result.

> I also have a problem playing A rolls because of the #5 Bass hole
> that was crescendo for A rolls is the Replay pneumatic for B rolls
> and the drawer.  This is especially bad if the transmission had
> trouble staying in rewind anyway as the fast opening of that hole
> gives the system a quick kick out of gear.  Is there a better place
> to put this tube?  Perhaps to the unused sub-intensity as these are
> both A expression pianos?

A "B" drawer on an "A" expression system should not cause the trouble
you are having, unless, of course, the tracker bar has been tubed
incorrectly.

If, in fact, it is an "A" expression system, then #5 bass should be
connected to the bass crescendo.  If it is a late system with only one
crescendo, then the crescendo should be tubed to #5 treble.  Some techs
also "tee" the tube to the crescendo, into both #5 bass and treble,
wherein can read both "A" and "B" roll coding, but, if this is a "B"
drawer, you can't do this as that nipple on the bass end of the tracker
bar has been given over to another purpose which is "Shut Off After
Rewind".

Very basic, but a mistake that can be made is starting to tube from the
first nipple on the bass end of the tracker bar which is only for "B"
systems and goes to the amplifier trigger.  This will throw your number
count out all the way!

The important function to note is that on the "A" system, #5 is fast
crescendo bass.

On the "B" system, with the extra tracker bar hole, this #5 is now
located in #6 position and the function is not for crescendo, but for
Shut Off "After" Rewind.  Consider this to be the same function as done
by the hole in the take up spool on an Ampico "A".  When this hole is
uncovered, and the player IS NOT set to replay, it sends a signal to
turn off the motor switch.  If the player is set for "Replay" on, the
signal to shift the transmission back to play comes from a finger valve
riding on the take up spool in a "B" drawer, or the hole in the take up
spool of an "A" system.

> One other question to those of you who have done numerous B drawers:
> On the four-valve block "rewind/replay/brakes/shutoff" box, one piano
> had the following and one did not.  Which works better?
>
> On the lower right valve block there is a cardboard insert into the
> top metal valve seat that has a small hole drilled into it.
> Obviously it is to slow down the off portion of its activity.  Since
> both of these drawers worked before the restoration, should this
> cardboard disk be replaced or not?  Was it factory or previous
> rebuilders that put it in?

This is the super-important part that, if not correct, will make the
motor turn off all the time.  Also, if this "restriction" is left out
or not in the proper place, none of the automatic play/rewind/repeat
functions will work properly.

The purpose of this restriction in the Signal tube to the valve that
operates the pneumatic that turns the electric switch OFF, is to
greatly slow down the response time of that part of the system.

It is this that allows you to put a roll on the AMPICO "B" and just
hook it on the take up spool.  As it is automatically thrown back into
play at the end of the cycle, you can't turn the take up spool to get
the paper roll wrapped entirely around it and entirely cover the
tracker bar.

If it were an "A" you would have to be sure the paper roll covered the
hole in the take up spool or the player would quickly go into reverse
and shut off, the instant you turned the power on.  With the "B"
drawer, you just hook the roll onto the take up spool and turn the
power switch on.  The restriction in the signal line to the power
switch valve, slows the reaction time down enough that the paper gets
to cover #6 bass (Shutoff after rewind) and the motor continues to run
and play the music.

This same delay is important as the roll is in rewind.  Every time that
#6 bass is uncovered with an "A" roll #5 fast crescendo, the motor
switch would quickly snap off, if the tube was not restricted.

This restriction was done at the factory by plugging up the end of the
nipple going to the valve of the pneumatic that turns the power switch
off.  Once plugged or soldered shut, it had a hole drilled through that
was slightly larger than the bleed for the pouch of this valve.

Bottom line is the pouch and bleed must be in perfect condition as the
entire operation is a balancing/timing act.  A fast signal will not
trip the switch.  A long, but slow signal, will after a couple of
seconds, cause the pouch to rise up enough to cause the valve to put
suction onto the pneumatic and thus turn the power off -- a
pneumatically operated time delay!

Unfortunately, the fine point of this ONE nipple being restricted, is
often missed by rebuilders.  The nipple can be used elsewhere in the
system causing another valve to NOT respond in time and making lots of
headaches.  It can be lost or the planned plug removed!  I would
suspect that the discovery of a paper restriction was probably what was
done by a previous tech who lost or could not locate the factory
original way of doing things.

However you resolve this necessary restriction is of your choice, but
it MUST be part of the rewind/replay/shut off system or it will NOT
work properly in a "B" drawer.  I prefer to solder a nipple closed and
then drill out a new hold just slightly larger than the bleed hole.
It's a lot more stable than a paper disc.

Hope this will be some help to find your ghost - Happy Halloweeneeeee.

Ken Vinen, Stratford, Ontario, Canada.

 [ See "Ampico B Rewind and Repeat System" at
 [
 [   http://mmd.foxtail.com/Tech/Ampico/
 [   http://mmd.foxtail.com/Tech/Ampico/amp52.htm  (1929 system)
 [   http://mmd.foxtail.com/Tech/Ampico/amp52m.htm (modified system)
 [
 [ Using a restriction at the top seat of valve "D" makes the system
 [ unbalanced and quite susceptible to the effects of stray leakage
 [ at the pneumatics and at the valve seat.  Better is the separate
 [ #65 and #67 bleeds at the pneumatic nipples, as shown in the
 [ drawings.  Valves A, D and C are ordinary "inside" valves with
 [ a large bleed and no ball check.  -- Robbie