View Full Version : Hyperion inrunner specs

Fly Time
09-10-2008, 08:51 PM
I'm considering buying a Hyperion Y22-L (http://www.allerc.com/Y22L.htm) brushless inrunner for use in a Cobri gearbox, but I am a little confused about some of the specs listed for this motor. Typically, the specs that I am most interested in are kv, input voltage, maximum continuous amps, and maximum peak amps, all of which I understand fairly well. Also general specs such as weight, dimensions, shaft diameter, etc.

For this particular motor, there is no mention of maximum amps, but it lists some other specs that I see frequently but haven't any idea as to what they mean: Ri and Io(@8.4v)A. Can anyone define these for me? And how do I use this info when selecting a motor?

Dr Kiwi
09-11-2008, 03:25 AM
The Rm and Io values relate to the Kv - the higher the Kv, the lower will be the Rm and the higher the Io.

As far as I can see ~25A, maybe as much as 30A, seems about the max current capability.

Your choice of Kv depends on what size prop you intend to spin - choose the prop, then work out the gear ratio which will allow the motor to spin that prop at <30A.

Usually a higher Kv motor can cope with higher current, but at lower voltage. If one follows the Medusa reasoning, the max watts for all the Y-22L motors (no matter what their Kv) will be exactly the same.

Fly Time
09-11-2008, 04:28 AM
So if I know what the kv of a particular motor is, are Ri and Io values even relevant?