SEN 2747

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  1. Variable Pitch Props
  2. Move your energy in the right direction
  3. Cylinders

Variable Pitch Props

From:DAVID BRAWN

“I am surprised that the FFTSC/CIAM have not banned VP props for this class.”
Surely if you think VP props should be banned on F1C then you should also support a ban on F1B/G? To have something allowed in one class but not another is just not logical. Just because a class is horrendously noisy, potentially dangerous, very expensive, is no reason to apply different rules to the other classes.

David Brawn


Editor’s reply

Well, F1C models have the highest performance of the World Champs classes, at the last World Champs F1C models were the only ones to get near 10 minutes.  If any change such as a VP prop made a performance improvement it would aggravate the position, potentially prompting a further reduction in engine run time. Already it is very difficult to run an F1C event, treating the participants fairly with respect to timing the engine runs, this would just make it ridiculous.  Seeing no one currently uses a VP prop it would not obsolete any existing equipment.

Maybe one of the expert readers would like to hypothesize on the potential effectiveness or not a VP prop for F1C.

Applying your argument about treating all classes the same, should not historic artifact in the F1C rules that permit a drastic change in flying surface area (F1A and F1B confine the  surface area quite tightly) be removed, thus rendering all folders obsolete.

The CIAM/FFTSC wisely applied a rule requiring all model to be launched with a hand on the fuselage.  This was to stop discus/tip launched models.  At that time a number of experiments had been carried out with discus launched F1B models.  Tip launching would favour F1B or F1Q because of the ease of starting the motor once in flight, the thought of discus launching one of these let alone a F1C for a FF flight line is frightening.  This rule stopped the discuss launch research before people invested in it and it became a problem, wise move.


Move your energy in the right direction

From:Ross Jahnke

I’m an artist not a physicist,

This discussion about vibration, reciprocal force vs. rotational force and
the number of cylinders needed to address the problem makes me feel good
about flying rubber and electric, where the energy of the motor is moving
in the correct direction from the start.

Ross


Cylinders

from Peter Becker

Cylinders:
48 run “quite smoothly” so you can work backwards from there!

– This You Tube video shows a 48 cylinder motor bike …https://youtu.be/BMyCJpznBsc


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Roger Morrell