The latest light weight high kV motor in the larger stator segment, sent over by Sumax for testing.
Check out the full list of motors in this series here
Published: Oct 10, 2017
I've had a few motors come across the bench from Sumax in the last few months, and the latest motor is major step forward in the design. It sheds the heavier construction of the previous 2206 motor in favor of a design with all the modern bells and whistles. This is one of the lightest 2207 motors to cross the bench, coming in just barely under 30g with 40mm of 20ga wire. The build quality is quite good, with tight tolerances, a tight air-gap, and high quality machining. The windings are neat and tight single wire winds. The wire gauge isn't as thick as some of the other single wire winds I've seen, but is fairly typical for the application. There are a couple of concerns that jump out at me related to the weight savings on this motor. The base of this design uses very thin metal where the mount screws are tapped. This increases the likelihood of both the screws stripping out the threads, and the mount points breaking under stress. The other point of concern is the lack of a lip on the flux ring on the bottom side of the bell. With a high torque baseless design motor, this of particular concern. Those points are fairly minor and may not prove to be major issues in practice though, and this motor hits all the other points without issue. The light weight will likely prove an offset to the risks for pilots looking to shave those last few grams from a 2207 build.
Given this motor falls in the same weight range as many 2206 and even 2205 motors out there, the 2207 stator already gives it an incredible advantage. The kV tested a bit lower than the stated 2600kv at around 2525kv, which shows in the results, but even so the performance here is very respectable. Even on heavy 5" props this motor easily clears 1500g of thrust with sustained current draw in the upper 30A range. On lighter props this motor delivers a decent balance of power and current consumption, hitting around 1400g with sustained current draw in the lower 30A range. The 2207 stator also gives it an advantage on the rate of response over equivalent kV and equivalent weight motors limited by a smaller stator size. This motor is likely to see it's peak peformance on a light weight racing rig with a low or mid-weight tri-blade. Overall a strong competitor in the light-weight range from Sumax.