Troy Taylor observes that his Reproduco has a music roll vacuum cleaner
mounted just before the tracker bar.  The "Catch-All Tracker Cleaner"
itself couldn't be simpler -- it is a round metal tube with one side
ground off to open a slot of 1/8th-inch height or less across the
entire width of a roll.

No, Troy, I'm fairly certain that these were not after-market devices.
Every 11.25-inch roll drive I have seen has the same gadget.  It does
catch the paper dust as the roll passes over it.  I don't know how much
air loss there is by having two places for the suction losses in the
roll box.  It is my guess that it is fairly small, but more than the
air loss by way of the tracker bar.

I would clean out the screen in the little glass jar rarely.  It has
so much room for dust to be trapped that I doubt that some of the jars
were ever emptied.  I'm surprised that the cleaner didn't catch on and
find its way to other players.  Coinola probably put the cleaner on the
instruments that would be in commercial use.

The doors on my instrument do not scrape against the supports for the
cleaner.  Can the metal tube be mounted further inward?

It occurred to me that the cleaner would add a bit more friction than
occurs with the suction of the paper against the tracker bar.  This
effect could have been used to alleviate the problem of the music
slowing or stopping when the vacuum is increased at the tracker bar.
By simply making the vacuum at the cleaner adjust inversely as the
tracker bar vacuum goes up.  In other words, as the drag at the tracker
bar goes up, the drag at the cleaner goes down.  Probably someone at
the factory would figure out a way to vary the pressure inversely using
a simply gadget -- like a small version of the roll motor governor.

Bill Chapman - in sunny La Quinta, Calif.;  85 F. today!