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MMD > Archives > February 1999 > 1999.02.24 > 13Prev  Next


Rewind Solutions for Electric Turbine Kits
By John Rutoskey

I've been waiting for this issue to come up!  Nothing is more
irritating than trying to get the Player Piano Company (PPCo) re-roll
equipment to work with a beautifully restored player mechanism.  It is
so difficult in fact, that I no longer use it, even when I am in a time
crunch.

I now design each re-roll unit individually for every piano I do, and
it is well worth the extra time spent.  I generally like the new parts
to look like they "grew there" and were original equipment.  Especially
with first class restorations in expensive, high end instruments like
Steinway, Knabe, Stieff, etc.

But let's say that I am faced with PPCo equipment in a well rebuilt and
tight player, and I must make it work dependably and smoothly mainly
because I never want to go back to that call.

For convenience sake in this essay let's also pretend the action is a
Standard just because it's very common and familiar to a lot of people
here.  You can use your own imagination to alter this article to fit
your own needs, the ideas are the same.

In the case of a player on low vacuum in a very tight action, there
should still be enough vacuum to shift the transmission IF you do not
let the pneumatic cut off its own supply when it goes into re-roll.
That means _do not_ tube it into the stack.  If you do, as the action
is going into re-roll, it is cutting off its own vacuum, so don't do
that.  Instead, contrary to the usual way, tube it into constant
vacuum.  It may collapse a bit even during re-roll if the paper flies
away from the tracker bar at all, but that's fine, it doesn't hurt
anything.  The idea with this particular unit is to get it to go into
re-roll as easily as possible.

When the player goes into re-roll, the stack is cut off, so with the
exception of the wind motor all of the vacuum is being directed to that
re-roll unit's valves and pneumatic.  If the pneumatic is not strong
enough to shift, with nearly 80% of the vacuum going to it, you have
a signal, valve, pneumatic, or linkage problem.

After you have changed the supply to constant vacuum either by tapping
into the top of the suction pump or coming off the reservoir with a
3/4-inch nipple, proceed with the following and then test as follows:

1) Use only one tube to the tracker bar for re-roll.  Your signal
_must_ be amplified if you're going to dump two pouches from one
tracker bar hole.  If you don't have the time or inclination to build a
primary valve unit, PPCo sells a "note amplifier" box or something like
that and it works like a primary valve.  Believe it or not, it seems to
operate very well, so put that in line next to amplify the signal.
Mount it flat and securely, cardboard side down.

2) Connect a tube to the output side of the primary unit and run that
tube to the "Y" connector on the valves on the re-roll unit.  Your
valves should now jump quickly and smartly when the re-roll hole opens.
Chances are, you were not getting a strong enough signal in the first
place to dump both pouches fully, and your valves were hanging about
half open, allowing 1/2 the amount of vacuum to enter the pneumatic,
plus a lot of atmosphere due to the fact that they were not seated
against the upper seats firmly resulting in quite a weak re-roll
pneumatic! If your mechanical linkages are smooth and well designed,
this should solve the problem.

3) Put a roll on the piano and play the tune at your desired lowest
possible listening level with all the notes still playing strongly and
repeating well.  Make sure it has a lot of big, heavy chords too.  Play
it to the end of the tune, before the re-roll hole goes over.  Now
throw the chain off the motor so you can move the paper by hand only.
Move the take up spool to bring the re-roll hole over the tracker bar.
Now does the re-roll pneumatic collapse strongly enough to shift the
gears? If not....

4) Do you have a tight pneumatic and valve unit?  If the soloist
pneumatics work great on low vacuum, I have a strong suspicion about
your re-roll pneumatic and valves.  Make sure that unit is tight! Take
it out, remove the valve blocks.  Put masking tape over the ports to
the pneumatic with it closed, now try to open it.  You should not be
able to open it up.  If you can, you have a leak in the pneumatic, or
the joint between the pneumatic and the board, or a crack, or the wood
grain is not sealed well.  Check it out and fix it until it's tight.
Make sure the valves are tight too.  Test them in both closed and open
position.  Put it all back together and it's still not working...

5) Do you have too much "linkage" to the re-roll? Are you using a good
mechanical advantage? Are your linkages all taken out, the bearing
points polished, the felt graphited, and the transmission well lubri-
cated and very clean?  **This is very very important!**  It should take
almost _no_ effort at all to shift the gears from play to re-roll.  If
anything binds, you have to fix it.  That means cleaning and graphiteing
all surfaces that are in contact with each other if necessary.  I am
wondering why in the original article, it was mentioned that the pneu-
matic was mounted on the piano's floor.  This doesn't seem like a good
place to get a direct mechanical connection to any reroll linkages.  A
pneumatic is at it's strongest when operated from a fully open position.
Get it as open as you can when it's in play position.

If there is vacuum, even very low, going to a tight pneumatic unit, and
the valves are working tightly and positively through a primary valve,
the pneumatic has NO CHOICE but to collapse tightly as its interior
atmosphere is being drawn from it, no matter how slowly the wind is
moving.  The idea is high volume, low pressure here.

Finally, I _never_ use the two-speed pump from PPCo.  The reason they
create this is so that you have a separate, slower speed on re-roll
that will keep you from tearing up your rolls.  Unfortunately, the
second speed kicks in at re-roll, much too late to save your rolls from
that critical "shredding" time, which is at the very end of the tune
when there is very little paper on the core, and the diameter of the
spool is small.  The first few turns of an old roll starting it's
re-roll is when most damage occurs.  The pump speed in the PPCo.  unit
does lower, but not fast enough to make the first few rounds of the
spool go slowly enough to lessen the damage possibility.

My solution here is to disable the sliding valve in the tempo box so
that full vacuum can never go to the wind motor during re-roll.  I
leave the slide valve in place, but simply disconnect it from the
linkages.  Thus, the roll creeps along on re-roll, due to the fact that
the wind motor is getting its vacuum from the tempo slide valve only.
This way, re-roll speed can be controlled fully from the tempo lever
during re-roll and even stopped completely should a "roll emergency"
happen to occur during re-roll.

Also, the last batch of pumps from Player Piano Company have a bad
triac on the board in the control unit that works for a few minutes,
but then quickly goes bad and must be replaced.  I have noticed this
within the past year only.  It causes the pump to lose speed control.
I do not have the part number handy but it is available from any
electronics house for a few dollars, and I will supply the replacement
instructions to any individual that needs them.

I hope I have shed some light on this issue, as it has been a problem
for me from time to time.  I invite any commentary on this essay.

Regards,

John D. Rutoskey
Automatic Music Machines
Baltimore, Maryland


(Message sent Wed 24 Feb 1999, 21:46:19 GMT, from time zone GMT-0500.)

Key Words in Subject:  Electric, Kits, Rewind, Solutions, Turbine

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