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Old 10-23-2008 | 06:20 AM
  #17  
da Rock
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From: Near Pfafftown NC
Default RE: Prop pitch........ practice : theory


ORIGINAL: dick Hanson


ORIGINAL: Jim Thomerson

Here is a site which will tell you all you want to know (well, maybe not).

http://www.supercoolprops.com/articles/pitchcompare.php
This is a case whre the POWERPLANT determines the prop specification
these setups are almost exclusively with engines which have a usable rpm range of 2000rpm.at best
My electric has a usable rpm range of 10000 rpm
most model IC setups have a usable rpm range of 50% of their rated max rpm .
The electric has max torque at zero rpm and if you ar a bit of a electric mods guy you can go from high amps to high volts to maximize power
The Killa Cycle motor cycle does just that
They start at max amps and once into higher speed shift from low voltage to high voltage
sorta like takeoff at low pitch and then shifting to high pitch on a prop.
In both cases the object is to keep the prop or motor working

Dick, it looks like your Killa Cycle shows the "POWERPLANT determining the prop" AND shows that with our electrics, the battery/voltage also has a great deal to do with determining it too.

Our models don't have the chip controls the Killa's do, but if we swap a 4-cell battery into a model that'd been flying with a 2-cell, the prop sees the world as a new man..... uh, an entirely different motor.

Looks like we're agreeing on stuff again. I gotta quit doing that, it looks like collusion.