The recent discussion of vacuum pumps for playing a foot pumper
had me thinking about how this could be done and still allow dynamic
expression.  As everyone knows, you create the dynamics largely by
the way you pedal.  A turbine pump can be slowed down or sped up but
not that quickly due to the inertia of the rotor.  To control the
dynamics (other than with hand controls which only perform certain
modifications) you need to vary the pedaling speed and force.

I have a design for a high speed vacuum regulator that can be used
in-line with a turbine pump.  As a test I just set one up with a
control valve that can be hand or foot operated.  You can gradually
change the vacuum for a crescendo or you can tap it for an accent.

It might be possible to make these at a reasonable cost as they are
quite simple.  I think they could be built out of stacked laser-cut
wood layers and a few other parts that might be possible to find ready
made.

If there is enough interest in this sort of device (it can also be
used for accurately regulating vacuum for other purposes, such as
testing or limiting playing loudness of other than 88-note players)
I will see if I can come up with a cost effective design.  In small
production volumes it is not going to be cheap.  I could also design
it as a kit if that is preferred.

Best regards,
Spencer Chase
spencer@mcn.org.geentroep [delete ".geentroep" to reply]