Episode Request: Choosing A Motor/Prop Combo


Foam Flyer
Hey Guys!

I know you guys did an episode on choosing props, and did a power test set-up. But I'm still new to electric power, and am getting confused by all the numbers on motors, which don't seem to translate from one manufacturer to another (Not all companies list what a 370 or 425 equivalent is(in fact, almost none of them do), etc). For a lot of your scratch builds you give a couple different motor sizes, but looking at them, they look like totally different set-ups and am confused how an 1100kv motor can work but also a 2450kv motor can work. And how an 1806 will work, but so will a 2210.

Something describing what to look for (especially something from HobbyKing would be nice) when scratch building your kits. And if there's a general rule to follow for props (such as 300 series should use x-y props, and 400 series should use y-z props (I'm only doing 3s)). I don't want to have to buy 4 different motors and 10 different props trying to figure out what works for a particular AC.



Skill Collector
I would second this request - perhaps with a white board and working out the equations of prop size to motor size to esc size to battery size with a few examples to better teach how to size the electronics. Then how to understand thrust generated from a particular setup, and which types of planes that thrust would be appropriate for. I don't want to let the smoke out of my esc cause I picked the wrong prop, or toss my FT Trainer into the air and discover I built a rocket ship by accident. :)