RCU Forums - View Single Post - Contra Rotating Propeller Drive for f3a 2m Pattern Planes
Old 06-28-2010 | 10:49 PM
  #3  
Brenner
 
Joined: Jul 2007
Posts: 806
Received 12 Likes on 11 Posts
From: Bridgman, MI
Default RE: Contra Rotating Propeller Drive for f3a 2m Pattern Planes

Hey Dave,

Rpm is little hard to measure because of the double props, but if I divide the readings I get by a factor of two, then I'm measuring 3750 rpm, which is pretty much what I predicted.

With a fresh pack I'm drawing 69 amps, and 2450 Watts.

3000 mah is for a day without a lot of wind. I'm reserving judgment until I fly it on a really windy day. My calculations are telling me that it should draw exactly the same mah from the pack as my C50-14XL does. If it's drawing any less, then it can only be due to an interaction between the front and rear props because I didn't include any of these effects in my calculations.

And yes, I'm still flying the same style as last year, but only with my old Integral. With this new Integral I'm able to fly much closer in, due in part to the constant speed characteristics, and a slower flight speed. It's much more relaxing to fly this way. I have a much better view of what the plane is doing, and much more time to react to it.

Also, I've set the motor up with zero degrees right thrust, and only 0.5 degrees of down thrust. The stab is set at zero degrees, and the wing is set at 0.5 degrees.