fvexecdir

Looking for some help. I'm in the process of building a Sterling PT 19 for old times sake. Making a few modifications to it including reducing the dihedral and adding ailerons. One of the challenges with this kit is the lack of cowling space withing in the aluminum cowling that comes with the kit.

I'm looking to put about 300 watts (12 cells at 25 amps) into the motor. The plane should weigh around 3 1/2 pounds and I'm guessing that the wing area is in the 425 - 450 sq in range. 18 - 19 oz per sq foot and, assuming 80% efficiency, about 85 watts per pound at the prop. Any motor suggestions that can fit into the cowl would be greatly appreciated. I've worked with speed 400 before, no experience with brushless motors -- therefore the request for some help.

Thanks in advance.

Henke Torphammar

You really should go brushless and li-po. atleast brushless! (there are good nimhs these days too)

the avarage motor handles 3-4 times its weight(grams) in watts. so you are looking for a ~100gram motor that handles 400watts, better safe then sorry. there are the AXI 2814/12. It will swing a 10x6 @ 30amps on 10cells or 3li-po. (don´t want to go 12cells as BEC works best up to 10 [:-] )

You could also use one of the cheap sp400 sized brushless inrunners and fit a gearbox 3:1 or 4:1 to swing a 13x7 prop or so.

fvexecdir

Henke:

Thanks for the reply.