This page is far from complete. As time permits, I will add pictures
and other pertinent information....
Tom S. from Virginia writes, "Do you have a procedure you use when
correctly replacing the "angle plate" back on its shaft. This item moves
the piano roll left and right in response to movement of the tracker bellows -
on a nicely functioning Standard player system? Mine got loose."
I don't know if I'd call it a procedure. In a nutshell, the cam has to be
free to move but not loose enough that it wiggles. It should never be
"snug" or have any sort of "drag" or resistance to moving swiftly.
Once it's set, use the locknut to secure it in that position. I do not
recommend using oil or grease as these will cause the cam to get
sluggish over the coming years..
Another aspect of adjusting the tracking cam has to do with its
physical relationship to the tracking bellows and the position of
the music roll. Ideally, when the music roll is perfectly centered on
the trackerbar, the tracking bellows will be 'centered' and the shaft
that engages with the tracking cam will be touching the center of
Most tracking systems have some sort of an adjustment capability
that allows the user to 'fine tune' the tracking system such that the
above criteria are met. However, obtaining the desired results
presupposes that the tracking bellows and their associated valves
are working correctly. So, in essence, it would be wise to insure
that the tracking bellows and valves are working correctly before
making any adjustments.
However, on the other side of the coin, since we don't live in a
perfect world, it may be possible that the tracking system isn't
functioning perfectly. In fact, it may have a slight imbalance
because of a slightly leaking bellow, a leaking valve, or aging cloth.
If that is the case, and you don't have the ability to rebuild the
assembly, it's still advisable to make a compensatory adjustment
so that the rolls track as best as possible. This helps prevent
unnecessary damage to the rolls and it makes it possible to
continue listening to the music until the problems are resolved.
While it may seem like a rather straightforward task, it is nonetheless
an important aspect of a well-functioning tracking system and I will be
making up another web page to cover the topic in depth. So, if anyone
has anything they think should be added, please respond.
===============================later, Tom wrote back===================
Hi John -
Thanks for your rapid reply. I was wondering
more on how much pressure the cam should be putting on
the upper roll mechanism when installed.
Seems to me that if I have cam just touch the
upper roller shaft, it gives the tracking mechanism no
chance to move the upper roller to the right as it is
Perhaps I should pull a roll on so that its
edges are centered on the tracking "ports" on the bar
and then install the cam so it holds the paper there?
If you have any time to answer this, I will much
And I replied:
The cam should be adjusted with a roll in place.
Because of your email, I'm starting to make a new
web page on adjusting the tracking system. The
basics are at:
What I will add to that page is the following:
If the cam is mounted on a shaft and held in place
by a set screw, do the following:
1. Put a known good roll in the spoolbox.
2. Find some way to secure the tracking bellows in
place such that both of them are open an equal amount.
3. Slide the cam onto the shaft and position it so that
the roll chuck shaft touches the center of the cam.
4. Push the cam further to the left, overcoming the
tension of the spring-loaded roll chuck on the left,
until the roll is perfectly centered on the trackerbar.
5. Tighten the set screw on the cam and test the
6. If the system continually favors one side of the cam
or the other. re-adjust the lateral position of the cam
Note: When the system is properly adjusted, the roll
will be centered on the trackerbar, the two tracking
bellows will be open (or closed) an equal amount, and
the roll chuck shaft will touch the cam in the center
of the operating area.
John A Tuttle