E-Flite Power 32 for a 6.5-7 lb Rascal 40 conversion
 

Hi All,
I've been flying an electric conversion of my SIG Rascal 40 (72" wingspan) for about 1.5 yrs and it has been going ok with a Turnigy 3548, 900 kV motor, 60Amp ESC, 4s 5000 mAh lipo and a 12x8 Master Airscrew Electric Only prop. Last weekend though, it went deadstick as a result of the motor packing it in. I think that motor may have been a little undersized and I'm thinking of replacing it with an E-Flite Power 32 (basically 42 mm diam and 770 kV). The catch is I don't want to change anything else and the plane weighs between 6.5-7 lbs.

I ran an online motor calculator that indicated this might draw 50A at full throttle and 13.88V for the battery. I don't usually fly hard and the motor continuous current rating is 42A so it would probably be ok but, for peace of mind, ... I want to ask if anybody here is flying a similar Power 32 setup and weight of aircraft? If so, what current are you pulling at a given throttle setting, do you have enough power or how about some free advice?

Thanks, in advance for any wisdom you can pass on,
Dave

RE: E-Flite Power 32 for a 6.5-7 lb Rascal 40 conversion
 

Well I just ran the numbers you listed with the MP32 or the Eflite 32, same motor. I used the 4s 5000 battery, 60 amp esc and a 136 prop. Puts out right at 50 amp with 111 ounces of thrust and 689 watts. Going with a 12X6 prop is says you will get 40 amps, 556 watts and 93 ounces of thrust.

I would say give it a flight with the 13X6 and see if it comes down warm or hot. I know with my MP 60 motor, I am well past the rating on full throttle yet I fly around at 1/2 throttle so it comes down cool to the touch.


Buzz.

P.S. Cal is [link=http://www.s4a.ch/eflight/motorcalc_e.htm]HERE[/link]

RE: E-Flite Power 32 for a 6.5-7 lb Rascal 40 conversion
 

Hi Buzz
Thanks for that. I was thinking about the same. I didn't try a bigger prop in the calculator though because I think that would draw more amps? That's the calculator I used too.
Dave

RE: E-Flite Power 32 for a 6.5-7 lb Rascal 40 conversion
 

I found the calc program "CLOSE" but it does vary a little. When I was putting together my Low Wing Trainer 60, I was running the numbers for the Monster Power 60 and found the heat and amps were a little over rated. I had less amp draw in real life then it said I would. Also said it would be real hot, motor is at or close to the out side air temps when I land.

Plug it in and see how it flies.

Buzz.