The only effective solution to this I have seen is on the Ampico B. The
piano rollspool brake is a band of felt wrapped around a 80mm wheel on the
end of the spool drive axle. A pneumatic pulls it tight. The tightness is
regulated by a valve and control finger which continually measures the
diameter of the paper on the roll!

All the other solutions seem to be going in the right direction, but have
stopped short of the goal.

The Ampico B needs this because it has to play 30mm small rolls and 100mm
jumbo rolls without stopping just as the final sforzando chords hit.

So, "hioslo" is your school, "hf" must be high frequency which is the
rate at which we hope to hear from you on the AMML, and stud has a very
impressive definition in your dictionary too.

Karl Petersen