Hi All,  The recent thread about air motor governors got me thinking
about some of the things we haven't addressed.  A few questions that
come to mind are

- Can the governor compensate for the difference in weight between
a jumbo roll and a short roll?

- Does the governor have the ability to compensate for the difference
in the drag presented by various types of paper?

- Can it be adjusted to compensate for the difference in the stiffness
or various thicknesses of cloth on the governor and/or the air motor?

- Without any form of feedback, can a governor actually govern the
rate at which the paper passes over the trackerbar accurately if any
of the above variables change?

In my opinion, the answer to each of these questions is 'No'.  And,
if that's the case, how can we calibrate the governor without first
knowing what the manufacturer deemed 'normal operating conditions'?

Must we just accept that the governor can only be calibrated to a
specific set of variables and likewise accept that if those variables
change, the tempo will change?

When you think about it thoroughly, every moving part from the knife
valve to the take-up spool has some effect on the tempo.

Musically,
John A Tuttle
Player-Care.com
Brick, New Jersey, USA