Danny Wilson started this topic in his MMD 130806 posting.  He wrote:

> I restored the piano player action myself and it played very nicely
> except for seven notes which "flutter", that is, they try to play each
> hole on a chained note. ... it is always the same notes which offend.

This malfunction is usually caused by poorly recut rolls, but the player
action also may be at fault.  Sometimes it is a combination of both.

Before punch-by-punch roll duplication became a reality, certain
recut rolls changed the geometry that was present on the original roll.
Those changes were subtle and often were hard to see, but they exceeded
the design parameters of the player.  One of the biggest problems
leading to this issue has not been fixed even in the punch-by-punch
copy process.  If the recutting perforator uses a smaller punch
diameter than what was used to make the original roll, problems may
sometime occur.

If the recutting perforator punch is too small and the step rate
remains the same as the original, the result in the recut is more space
between perforations.  If that additional space exceeds the design
limits of the players bleed-balance ratio, the note will repeat during
the chain.  Simply stated, there is just too much blank paper to hold
the note in the "on" position in the chained perforation.

Knowing this, before anything is done to the player mechanism, study
the problem again and verify that the roll is not a poorly duplicated
recut.  Examine the chain as it passes over the tracker bar slowly.
Does the tracker hole nearly close (less than 25% open) at any time
in the chained area?

If the problem exists using original rolls, there may be two causes.
First, suspect that the bleeds are clogged, and then suspect that
the tracking is off.  It may be a combination of both.  The third
possibility is over zealous sealing of the pouches as pouches were
rarely meant to be 100% airtight.  Generally, making the pouch 100%
air tight will require increasing the bleed size.

In the case of a Duo-Art grand, fixing clogged bleeds is one of the
easiest repairs on this type of piano.  The bleed strip is covered with
pneumatic cloth that can be easily removed.  A small wire or drill bit
can be used to clear a clogged bleed.  If you have a very late style
Duo Art, the bleeds may be drilled holes in the elbow nipples on the
bleed strip.  If those elbows are turned, the bleeds will be blocked.
Simply turn the elbows to open the bleeds.

If the tracker does not keep the paper dead centered over the holes,
smaller hole punches in the paper will add to the off center position
to create enough "coverage" to cause the notes to repeat.  If the
bleeds are partially clogged with shellac, all three problems can
accumulate to cause the problem.

Finally, I don't think removing the action is the right thing to do.
Investigating all these other issues will certainly solve the problem.

Report back when the problem is solved so we can all benefit!

Bob Taylor
Missouri