This high KV large stator motor was made by SunnySky specifically to XFoot's specifications, who kindly sent it over for testing.
Check out the full list of motors in this series here
Published: Dec 30, 2016
X-Foot was a new name for me when I was contact about this motor. This is a small miniquad business that wanted a some very specific things out of a motor which didn't exist in the current offerings. As a result they approched SunnySky to make this custom motor, and man is it a beauty. SunnySky has always made fantastic quality motors, and this one is no exception. Build quality is phenominal. It has all the bells and whistles of the modern motors out there, and is very well thought out build. The airgap is very tight, and the machining and tolerances are fantastic. One of the best things about this motor is the shaft. It is a single machined titanium alloy shaft, but the real awesomeness here is on the bottom. The shaft is held in place with a screw, like many of the other motors on the market, but instead of a tiny soft metal screw, X-Foot has specified a 2mm hex drive 12.9 steel screw. This means it won't strip because of the hard material, but also that it uses the same driver that is typically used on the screws in the frames and motor mounts, making maintenence very easy. The only downside with this motor is the weight. At 35g it matches the F60 and Cobra 2207 motors in weight, making it a bit heavy for some tastes, depending on what a pilot is wanting in their quad.
Given the performance we've seen out of the 2205 and 2206 high KV motors, I was very interested to see how a high KV motor with very tight air gap and strong magnets would do. This motor is a monster. The lightest weight prop I tested, the HQ 5x4 prop, put out over 1300g of thrust at just at 30A. That is insane. The heavier 5" props were easily clearing 1600g of thrust. The only downside here is the amp draw, but on a very light racing rig, the unloading is likely to result in quite managable current draw. The current here is not that much higher than what we saw on the Emax RS-S motor, but the larger stator clearly has an advantage pushing the heavier 5" props. The torque under static load on this motor is unbelievable. Acceleration and braking are both impressive. The motor also ran very smoothly through the tests, showing very little vibrations or roughness. Overall this is a very impressive motor, but current and weight will definitely need to be taken in to account when making a decision. The niche for these is definitely the light weight racer on courses that will be able to take advantage of the insane RPMs, that are short enough for the current draw to not be an issue.