Author Topic: Great Planes RV-4 going electric (Read 598 times)

Fred Cronenwett · « **on:** July 30, 2011, 12:58:49 PM »

I am getting the final touches on my Great Planes RV-4 together and was wondering if anyone else has converted this RC kit to CL and installed electric power. I have already installed the E-32 for power but has anyone else installed electric and what motor did you install?

This model has a 55" span will come in about 6-7 lbs depending on what batteries I install. The bare model now comes in at 4 lbs with the motor installed but still needs a few more details. It will be using DSC electronic controls for throttle and flaps.

I will be flying this model in CL sport scale.

Land Softly,
Fred Cronenwett

John Rist · « **Reply #1 on:** July 31, 2011, 05:03:18 PM »

I have converted a couple of RC Extra 300S to control-line scale (slime burners). The biggest problem I have had was landings. With all of the extra weight of servos, battries, etc the wing loading gets high. With pratice they will land but I found that I had to come in hot to keep them from bouncing the landing. Keep the CG at or in front of the RC location. Also don't forget that with electric the CG does not shift with fuel usage. Looks like the RV-4 has a big wing (no taper) and this should help. Good luck. You will love the reliability of the electric power.

PS Use small flight battries to keep weight down. Contest scale flights are short compaired to stunt pattern flights. My LA-5 with a 4S 3,000 will do 3 complete flights an a charge. I would go smaller but I need the weight for correct CG. My LA-5 (Brodak kit) came in at 4.5 LB ready to fly.

Tim Wescott · « **Reply #2 on:** July 31, 2011, 05:28:29 PM »

That motor seems awfully small for the plane. If you were flying that much plane in CLPA you'd need a motor capable of 800W continuous, 1200 peak (this is extrapolating from the numbers in the "list your setup" thread, via my sprand-banking new tool: http://stunthanger.com/smf/index.php?topic=22637.0). Even considering that for scale you'll be flying a lot more sedately, the RV-4 is designed for .40 sized engines. You're going to put a 32-size motor in it, then you're going to pull lines around.

I haven't done this before so I could be all wet -- but it sure seems you need more power than that motor will comfortably supply.

Dennis Adamisin · « **Reply #3 on:** July 31, 2011, 10:17:51 PM »

Folks have been clamoring for IC equivalents for electric motors, however what has been coming out is badly inaccurate. However in your case you should be OK.

Case in point: E-Flite makes a "Power 25" that has recently become a very popular motor. The "25" will turn a 13x5.5 prop at 9500 RPM and haul a 4 lb airplane through the stunt pattern. You will never find an IC 25 that will turn that prop at that RPM!

Your Power 32 is 7mm larger in diameter and 2 mm longer than the Power 25, it will be that much stronger. Use a 13x6.5 or a 14x7 prop on it and hang on tight!

Fred Cronenwett · « **Reply #4 on:** August 17, 2011, 04:07:50 PM »

I flew the RV-4 today, 6.5 lbs, and the E-32 with a 4S battery flew the model with authority at 1/2 power from a scale point of view. If I was trying to aerobatics I would need more power, but for scale the E-32 does just great.

I have been using the general rule 100 watts per lb and so far it's worked out every time.

Fred

Author Topic: Great Planes RV-4 going electric (Read 598 times)

Fred Cronenwett

Great Planes RV-4 going electric

John Rist

Re: Great Planes RV-4 going electric

Tim Wescott

Re: Great Planes RV-4 going electric

Dennis Adamisin

Re: Great Planes RV-4 going electric

Fred Cronenwett

Re: Great Planes RV-4 going electric