ORIGINAL: tigerdude426
Still not sure about these electric motors. This is a guess only. PLEASE HELP:
Eflite Park 400 outrunner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9x4 electric prop
Eflite Park 450 outrunner for Electric J3 cub . . . . . . . . . . . . . . . . 9x6 electric prop
AXI Goldline 2826/12 electric for Lanier ST-40 Super Trainer . . . . . 13x10 electric prop
You need to state the weights of each plane, the battery capacity, and what you want your power ratio to be.
e.g. do you want "scale" like flight? etc.
That helps determine what prop size to use in each case.
BTW: I use an 10x6E prop on an Ultimate 3D FX using the same E-flite 400 Outrunner.