Hey fellows

I have foamy that's weight is between 12 and 14 oz, I have two E-flight motors the Park inrunner 370 and the E-flight park inrunner 400, I would like to use the 400, cause I'm using a phoenix 25, and a thunder power 1320 11.1v 3cell,, But what I dont know is what size prop do I need for the 370 and 400..

Thanks a lot

Randy

Which gear ratio do you want to use and what is the kv of your motors?


Bevo

I'm not really sure what you mean about gear ratio, unless you mean the size, if so I dont know any thing about that, but on the motors the 370 says 5400 KV and the 400 says 4200 KV..

Thanks

The 400 inrunner would destroy that plane. I'm talking hover at less than 1/4 throttle power. All you're doing is adding weight. Go with the 370 and about a 5.33 ratio and a 11x3-12x6 prop.

when you say a 5.33 ratio, are you talking about the gear???


Thanks

Yup.

Perhaps we need to clarify what kind of a plane this is. Is this a pusher zagi/jet were you want a direct drive, or is this a 3D foamy where you need a front mount.

The advise they are giving you is for a front mount 3D style foamy, you need to put in a gear box to reduce the rotation so you can put on a large prop. GWS and Cobri and MPI make gear reduction sets. (5.33 to 1)

If this is a jet pusher direct drive I would start with a 5 X 3 and measure the amps.

I too am going to make an assumption that we're talking about a 3D foamy......Hey we're in the 3D Electric Flying forum..... Anyhow, the Park 370 would be the best bet, but with the higher Kv of 5400, a higher gear ratio will be needed. 6.5:1 would be a better starting point with an11X7SF prop, but a watt meter should be used to determine whether you're over amping anything, and will help in determining which prop to use..