Wolter

I have a Heathkit Commander Trainer R/C plane, Model RP-1173, which I purchased back in ’82 when Heathkit was getting out of the kit business. It is an all-Styrofoam, MRC .15 nitro powered model that I never built. I tried to break in the engine but it never ran right so the thing got shelved and has moved with me throughout the years in its original box. I Googled this kit but came up with no hits. It has a 4’ wingspan, with special anti-stall wing tips, high dihedral wing, ~8” cord and the fusalage is 30.5” long. It has a tricycle landing gear with a steerable nose-gear.

I’m thinking of repowering it with electric and would like suggestions on how to go about doing this? I want to use it as a trainer and fun flyer. What size motor, prop and what kind of gearing should I try? I can shed weight by using smaller servos, making lightweight landing gear, etc. I want to do this on the cheap so brushed motor and NiMH power source.

Thanks for any help!

stefanP

My Feedback: (2)

Wolter do you know what the plane weighs? Also how much experiance in electric power do you have?


stefanP

Wolter

The plane is about 300 grams for the foam alone. Two servos, a receiver, ESC and flight battery would need to be added to that. A bit under 1 Kilogram? The original .15 glow engine spun a 8” X 5” prop, if that’s of any help.

I have very little experience with electric planes but lots with electronics, motors, RC trucks and boats and the like. I have absolutely no qualms about this aspect of the project.

I know I said brushed but looking around I’m thinking something along the lines of the AXI 2808/16 on 7 cells for about 110 watts max. Am I in the ballpark?

http://www.hobby-lobby.com/brushless-axi2808.htm

Wolter

After lots of web surfing, looking at planes with similar specifications, and a few email from a helpful fellow in this group, I decided on the following:

Ultrafly A/30/24 brushless motor & gearbox (400 size brushless motor good for up to 180 watts and ~80% efficient), Castle Creations Phoenix 25A controller, Hitec HS81MG servos, my old ACE R/C Radio and receiver and a KAN 1100 mAh battery pack. I will select the number of cells and prop to maximize the efficiency of the motor while maintaining maximum prop diameter. I already have the Ultrafly and controller in hand. I have never played with brushless and I decided this was the R/C craft to try it on. It’s going to be fun!