Having test-run most of the small to medium Suppo motors, including all the previously available “2217” series, I purchased from BP Hobbies for evaluation, a 2217-4 (2200Kv) motor which seems to have appeared on the scene relatively recently [BP lists it as of 2 June, 2012]. As usual, I ran no-load tests, and several test props in order to provide such basic data as Kv, Io, Rm, max. amps/max. watts, suitable prop sizes and "efficiency".

This gold anodized motor looks exactly like a Suppo, but has “Cheetah” engraved on the bell......maybe a BP "house brand" since they stock Cheetah servos and batteries. It is very nicely machined, the bearings spin freely, the bell seems to be true, and the windings look reasonably neat. This is a 12-arm stator, 14-magnet pole motor and is configured for rear-mounting. It was supplied with a black X-mount (four 3mm holes at 16mm/19mm centers for the motor; four 3mm holes at 33mm centers for mounting). The stator is 22mm in diameter and 16.45mm deep (46 laminations indicate 0.358mm thickness). It has factory-fitted 3.5mm bullet connectors. Female connectors and yellow shrink-tube for the ESC are supplied. The motor shaft is 4mm…. the supplied collet adapter is unusual yet useful in having a 5mm threaded prop shaft (rather than the typical 6mm, often with an annoying 7mm shoulder). The bell has a chrome magnet ring (21mm deep, 28mm in diameter) and, overall, the motor is 48mm in length (including 14mm of exposed shaft. The motor came in a blister pack, with the aforementioned accessories, but no information or specs. other than “2217-4, 2200Kv”.

Using a Dualsky 40A ESC, I ran my usual no-load tests at 7v, 8v, 10v…. and that’s when a little red flag appeared….the motor got remarkably hot from just a brief run at each voltage and I had to let it cool down between no-load runs. I was surprised to read 4.50A @ 10v…. a 51g Suppo 2212/6, at approximately the same Kv, only draws half that…. and a 72g Suppo A2217K/6 (~1530Kv) only 2.00A @ 10v. I then tried to run a series of prop tests (at 7v thru 11v) starting with 4.5x4.5 EMP and Zagi Carbon and in each case the motor got to over 50°C remarkably quickly. My Power supply is limited to 20A-25A so I needed to bring out a 3s2p TP 4200 pack to test the 6x5 EMP… this drew 27.40A/295W and the motor coped with that fairly well… but, having switched from PS to Lipo, I didn’t record a final temperature. To complete a fourth run I went smaller rather than larger, and tried a 4.1x4.1 EMP…… being impatient to complete the series I didn’t allow the motor to cool down completely after the previous run, so don’t read too much into the 4.1x4.1 EMP temperatures.

Having entered my data into DriveCalc, the program gave me 2200Kv (exactly as spec.) with an Rm of 0.066Ω. However, I am not convinced of the accuracy of the projections DriveCalc is giving me when I plug in props I have just tested…..typically I find that DriveCalc predictions match my measured data fairly well, but in this case they are well astray. This motor seems to be not particularly efficient (68% max. at 25A) but the efficiency curve calculated by DriveCalc seems too flat to be true and the computer-projected max. amps (50A) seems wildly optimistic. The RPM as a percentage of Kv x V is a telling parameter… ideally this figure should be around 75%, yet this motor was spinning these small props at >80%, even >90%... that would suggest that it was under-propped…. yet I fear that larger props, drawing far more current, would generate excessive temperatures!

As far a performance goes, I cannot see using this 75g motor to spin 6” props when one can get comparable performance at greater efficiency with a 51g Suppo 2212/6 (~2315Kv), a 54g Grayson Super Sonic v2 (~2190Kv) or a 58g SunnySky X2212/6 (~2030Kv). I wonder whether the "Cheetah" is a knock-off of a genuine Suppo.. I have been impressed with the performance of all the other 2217 Suppos I've tested.. this 2217-4 doesn't seem to measure up.

Cheers, Phil

Very Good motor for 4slipo for Funjet.

Even to 295 watts, 3.93 watts/g. the %NLS is 81%

Any Chines motor is only 70% o less.

My concern, Manuel, is that my test motor got fairly hot, fairly fast at much lower input than 295W.....I need to charge up some packs and try a few other props....maybe, with good cooling in a Funjet, it might survive??

In a test static, high Kv motors, receive much torture.

But in a Fun jet, the motor receives a large amount of air.

drive calc, mark me 77% efficiency, which leaves only 68.7 watts of heat.

Maybe APc 4.7x4.7 for 4slipo.

The motor at BP hobbies now says A2217-4 2000kv. Do you think this is the same motor that you tested or has it been changed? I don't see a 2200kv.

http://www.bphobbies.com/view.asp?id...7&pid=G1894516