Dale at EP Buddy kindly sent me a selection of small to medium sized SunnySky/EP Buddy motors. http://epbuddy.com/index.php?main_page=index&cPath=31 I chose sizes and Kv's which match up with other brands which I have tested previously ("remote head-to-head testing???"). As you can see they are anodized much the same green as Tacon outrunners, but they are very different in form, and are obviously not from the same stable.

Here is the list:
2204-1800
2208-1500
2212-980
2212-1400
2212-1950
2216-1250
2814-1000

I think Louis Fourdan is getting the 2820-size, since that is too potent for my test rig.

Bench testing will get underway soon... here are some photos just to get the ball rolling.... each motor comes with X-mount and screws, and collet prop adapter (radial adapter for the 2814), but nowhere in the packages are there any specs such as weight, max. amps/watts, recommended prop sizes......

Dale also sent me a PowerLog 6S... which comes with various accessories and a Manual on CD which, when printed, is 22 pages long. Clearly, I have some reading ahead of me!

Cheers, Phil

looks like you will be busy

Motor #1: SunnySky/EP Buddy X2204-21 (~1875Kv). This motor, when fitted with 1.8mm Hyperion Gold connectors, weighed in at 22g. It is 27.0mm diameter and 18.8mm front-to-back. It is a 12-arm stator, 14-magnet pole motor and the magnet ring is 5mm deep. I’m told that the stator plates in this series are 0.35mm, but that a newer series is due out soon, and will have 0.20mm thick stator plates… it will be very interesting to see what effect thinner plates have on performance. The 3mm shaft is, overall, 23.3mm long, with just 3.5mm exposed ahead of the built-in prop-saver. This prop-saver has a hub for 5.5mm prop hub bore (and the two additional hub spacers which are supplied, suit 7mm and 8mm prop hub bore). The two prop-saver screws are 2.5mm x 7mm flat-head at 120 degrees to each other. The four-armed built-in back-plate mount has 2.1mm holes at 31.5mm centers. Four 1.8mm mount screws and four O-rings are supplied with the motor. The machining and finish on this motor are excellent.

I set up this motor on my ply-disc mount on the test stand (see photo). I used my usual Zurich power supply, Medusa Analyzer Plus, Eagle Tree v4 with RPM and temperature probes, and Ohaus CS2000 digital scale. I used my “no-name” IR Gun, a Hobbico Digital MiniTach, and a Castle Creations TB 9A ESC.

I ran no-loads at 7v, 8v, 10v, and then a series of props at 7v-11v on the PS ranging from 4.5x3 GWS HD up to 7x3.5 GWS HD. I also tried 7x4 APC SF and 8x4 GWS HD on 7v and 7.4v to simulate 2s operation. The motor ran absolutely smoothly with all these props. Drive Calc estimated Kv as ~1875Kv (fractionally higher than the spec. of 1800Kv) with an Rm of 0.40 ohms. The critical “RPM as % of Kv x V” indicated that most of the props, even up to 7x3.5 GWS HD, did not unduly load the motor, but that the two largest props (7x4 APC SF and 8x4 GWS HD) were both bogging the motor down (65% and 61% respectively). With the 8x4 GWS HD especially, this low “RPM as % of Kv x V“ [hence…over-loading] was reflected in the rapid rise in temperature… a few seconds at WOT was enough to get the temperature up to 52C. For indoor flying where light weight and high thrust is of the utmost importance, one might get away with brief bursts of WOT with these larger props on 2s…. but for more continuous use, smaller props will work better!

Cheers, Phil

Motor #2: SunnySky/EP Buddy X2208-11 (~1450Kv). This motor, with factory-fitted 3.5mm bullet connectors, weighed in at 46g. It is 27.55mm diameter and 25.0mm front-to-back. It is a 12-arm stator, 14-magnet pole motor and the magnet ring is 11mm deep. The 3mm shaft has 10.5mm exposed for the supplied collet prop adapter, and it has a flat machined on it to suit a set-screwed adapter too. The motor is configured for rear mounting with 3mm threaded holes at the typical 16mm/19mm centers. The supplied X-mount has inner holes to suit the motor and four 3mm holes at the ends of the arms at 34mm centers. Four 3mm x 5mm flat-head mount screws, a collet adapter for 3mm shaft [pictured......it is suited to 6mm prop bore rather than the more usual 5mm] and a spare 3mm C-clip are supplied with the motor. The machining and finish on this motor are, like the X2204-21) excellent.

I set up this motor on my Axi “stick-mount for 22mm motors” on the test stand (see photo). I used my usual Zurich power supply, Medusa Analyzer Plus, Eagle Tree v4 with RPM and temperature probes, and Ohaus CS2000 digital scale. I used my “no-name” IR Gun, a Hobbico Digital MiniTach, and a Motrolfly 20A ESC.

I ran no-loads at 7v, 8v, 10v, and then a series of props at 7v-11v on the PS ranging from 7x5 APC E up to 9x5 GWS HD. The motor ran impressively smoothly with all these props.

Drive Calc estimated Kv as ~1450Kv (fractionally lower than the spec. of 1500Kv) with an Rm of 0.193 ohms. The critical “RPM as % of Kv x V” indicated that the props I tried, except for the 9x5 GWS HD, did not unduly over-load the motor [all the 7”-8” props delivered >70%]. The 9x5 GWS HD however, with a low “RPM as % of Kv x V“ at only 62%, produced an excessive rise in temperature… the standard series of bursts to WOT got the winding temperature up to 72°C. The data suggests that my ‘guesstimate’ of a 15A limit for this motor is about right…around 150W-160W is just over the “rule of thumb” 3W/g.

Cheers, Phil

Phil: Thank you very much for the detailed data and all your efforts.
Since we have not got our own test jig yet, we are not able to provide detailed data such as specs such as max. amps/watts, recommended prop sizes, and so on. The data sheet will be available as soon as we get our own data.
SunnySky is a reputed manufacturer of quality and affordable brushless motors in China. They are also an OEM supplier of several famous brands of motors and parts sold all over the world. However, the SunnySky brand is totally unknown in this country. Presently we are working closely with the company to bring more affordable motors to the market.

Will your website allow us in oz to buy motors ?.

Originally Posted by aeromaniac

Will your website allow us in oz to buy motors ?.

SunnySky is the manufacturer. We are the dealer: www.epbuddy.com

Motor #3: SunnySky/EP Buddy X2212-13 (~910Kv). This motor, with factory-fitted 3.5mm bullet connectors, weighed in at 58g. Like the X2208 it is 27.55mm diameter but 30.0mm front-to-back. Like the rest of this series it is a 12-arm stator, 14-magnet pole motor. The magnet ring is 15mm deep. The 3mm shaft is 42.5mm long and has 10.5mm exposed for the supplied collet prop adapter, and it has a flat machined on it to suit a set-screwed adapter too. The motor is configured for rear mounting with 3mm threaded holes at the typical 16mm/19mm centers. The supplied X-mount has inner holes to suit the motor and four 3mm holes at the ends of the arms at 34mm centers. Four 3mm x 5mm flat-head mount screws, a collet adapter for 3mm shaft [pictured......it is suited to 6mm prop bore rather than the more usual 5mm] and a spare 3mm C-clip are supplied with the motor. The machining and finish on this motor are, as for the X2204 and X2208, excellent.

I set up this motor on my Axi “stick-mount for 22mm motors” on the test stand (see photo). I used my usual Zurich power supply, Medusa Analyzer Plus, Eagle Tree v4 with RPM and temperature probes, and Ohaus CS2000 digital scale. I used my “no-name” IR Gun, a Hobbico Digital MiniTach, and a Motrolfly 20A ESC.

I ran no-loads at 7v, 8v, 10v, and then a series of props at 7v-11v on the PS ranging from 8x4 GWS HD up to 12x8 GWS HD. The motor ran impressively smoothly with all these props.

Drive Calc estimated Kv as ~910Kv (considerably lower than the spec. of 980Kv) with an Rm of 0.23 ohms. The critical “RPM as % of Kv x V” indicated that the props I tried, up to and including the 10x6 GWS HD, did not unduly over-load the motor [these 8"-10" props delivered >76%]. The 11x7 GWS HD however, with a lower “RPM as % of Kv x V“ at only 66%, didn't produce an excessive rise in temperature, but it was beginning to bog the motor down somewhat.... the 12x6 GWS HD was a little worse (64%) and the 12x8 GWS HD was clearly to much for it (57%... and a motor temperature of 71C by the end of the test series). The data suggests that my ‘guesstimate’ of a 15A-16A limit for this motor is about right…around 150W-160W is under the “rule of thumb” 3W/g.... but these are large props. DriveCalc indeed suggests 16A as the upper limit and calculates that efficiency would be about 62% at that power level.

Cheers, Phil

Motor #4: SunnySky/EP Buddy X2212-6 (~2030Kv). All the preliminary details for this motor and for my test procedure are exactly like those for its 910Kv relative... reviewed as Motor #3 in the post above.

I ran no-loads at 7v, 8v, 10v, and then a series of props at 7v-11v on the PS ranging from 4.1x4.1 APC E up to 6x5.5 APC E. The motor ran impressively smoothly with all these props.

Drive Calc estimated Kv as ~2030Kv (somewhat higher than the spec. of 1950Kv) with an Rm of 0.094 ohms. The critical “RPM as % of Kv x V” indicated that none of the props I tried unduly over-loaded the motor [all these 4"-6" props delivered >76%].... and in no case did the motor get anywhere near a worrying temperature. The rule of thumb of 3W/g might suggest that 175W might be about the limit for this 58g motor, but experience has led me to believe that high Kv motors spinning small props seem to be able to cope with higher power levels (than low Kv motors with large props). My ‘guesstimate’ was 25A for this motor, which is where I drew the line for the various Suppo 2212-6 motors I've tested. I entered my data into DriveCalc to obtain "true Kv", Rm, and efficiency figures. DriveCalc calculated 68% efficiency at 25A.... such an amp draw is close to what my test motor drew with a 6x5.5 APC E. But DriveCalc further suggested that this motor could be pushed far beyond 25A... indeed to 42.5A on 3s... and still deliver 62% efficiency. Looking at my temperature data, I could not imagine 42.5A... maybe 450W.... through a 58g motor.... but I did go the extra yard and set the motor up with a 7x5 APC E on a not fully charged Grayson Hobby 3s 2200 pack. Initially this drew 32.10A @ 10.5v (332W)....yes, I had switched out the Motrolfly 20A ESC for a Markus 45A ESC!.... so then I decided on an extended run to test the waters (and the limits). I was very impressed.... the motor settled to about 31A @ 10.3v at WOT and I simply let it run wide-open for over two minutes... the temperature as recorded by the v3 temperature probe attached to a rear mount screw settled to 40C and stayed that way. After consuming 1191mAh I shut it down... the temperature from my IR Gun pointed at the windings through the front of the motor had reached 64C... the Eagle Tree probe read 40C at the end of the run, and climbed over the next minute or so to a peak of 67C....yes, that's a bit hot, but heck this was a static run with the prop in pusher mode... not much air draft cooling! If your aircraft was flying at or close to the 70mph pitch speed, surely the motor would run a lot cooler. With "RPM as % of Kv" at 69%... this 7x5 APC E is on the limit in terms of over-loading... but appears to be okay for it....any prop drawing 42.5A would surely over-load the system!

All in all, a fairly spectacular performance from this motor (34oz thrust at 68mph from a 58g, <$20 motor)... someone else can push the limits even further to see if DriveCalc predictions (42.5A/450W are at all attainable!).

Cheers, Phil

Motor #5: SunnySky/EP Buddy X2216-7 (~1390Kv). The details for my test procedure are exactly like those for its smaller relatives... reviewed as Motors #1-4 in the posts above.

This X2216-7, with factory-fitted 3.5mm bullet connectors, weighed 72g (the SunnySky indication of 68g must be the bare motor). The motor is 27.8mm diameter by 34mm long. The magnet ring is 19.5mm deep. The 3mm shaft is 50.35mm long and has 11mm exposed for the prop adapter. It has a rear collar attached by a single set screw to prevent the bell and shaft moving forward under power (the motor is configured for rear-mounting).

I ran no-loads at 7v, 8v, 10v, and then a series of props at 7v-11v on the PS ranging from 6x5.5 APC E up to 9x5 GWS HD. I also tried the two smallest props (6x5.5 APC #E and 7x5 APC E at a set 14.0v. The 10x6 GWS HD was run using large 2s and 3s packs since my power supply is limited to about 14-15A on 2s voltages and 25A on 3s voltages. The motor ran impressively smoothly with all these props.

Drive Calc estimated Kv as ~1390Kv (significantly higher than the spec. of 1250Kv) with an Rm of 0.125 ohms. The critical “RPM as % of Kv x V” indicated that, other than the 10x6 GWS HD, none of the 6"-9" props I tried unduly over-loaded the motor .... and in no case did the motor get anywhere near a worrying temperature. The rule of thumb of 3W/g might suggest that 220W would be about the limit for this 72g motor... it coped well enough with at 10.5v/21.70A/227W with the 9x5 GWS HD.. but a high C rate pack delivering higher voltage under load, might result in far higher amp draw...I fear that 9x5 GWS HD might be excessive. My ‘guesstimate’ would be 25A for this motor, since my run with the 10x6 GWS HD at 29.50A/324W produced a rapid rise in motor temperature to >50C. I entered my data into DriveCalc to obtain "true Kv", Rm, and efficiency figures. DriveCalc calculated 67% efficiency at 25A.... such an amp draw is close to what my test motor might have drawn with a 9x5 GWS HD and a high quality pack. DriveCalc suggested that this motor could be pushed to 33A, but at this point it would deliver only 59% efficiency. Looking at my temperature data, I can't imagine 33A... maybe >350W.... through this 72g motor.

Cheers, Phil

Originally Posted by Dr Kiwi

Dale at EP Buddy ...

I think Louis Fourdan is getting the 2820-size, since that is too potent for my test rig.

Cheers, Phil

Hi
Nothing got, up today
My bench is hungry !
Louis

I'll have to beat up on Dale to get some motors to you... from those I've tested they are good quality at a remarkably cheap price.

Motor #6: SunnySky/EP Buddy X2814-8 (~1000Kv). The details for my test procedure are exactly like those for its smaller relatives... reviewed as Motors #1-5 in the posts above.

This X2814-8, with factory-fitted 3.5mm bullet connectors, weighed 110g (the SunnySky spec was 105g). The motor is 35mm diameter by 36mm long. The magnet ring is 17.7mm deep. The 4mm shaft is 50.35mm long and has 16mm exposed for the prop adapter. It has a rear collar attached by a single set screw to prevent the bell and shaft moving forward under power (the motor is configured for rear-mounting). Since this motor was a fraction too large to suit my Aeronaut "Beam mount for 600" in normal configuration, I used the supplied radial prop adapter (6mm threaded shaft) and rear-mounted the motor.

I ran no-loads at 7v, 8v, 10v, and then three props at 7v-11v on the PS ranging from 9x5 GWS HD up to 11x7 GWS HD. The 11x7 GWS HD was also run on a 3s pack, since my power supply was at its limit (25A) when set at 11v and could deliver only 10.6v... the 3s pack delivered 11.1v @ 27.30A. The motor ran impressively smoothly with all these props, and later I'll try perhaps 12x6 and 13x4 to test the limits a bit further (3W/g would suggest 330W should be possible). For those tests I'll need some large 2s and 3s packs to be charged up!

Drive Calc estimated Kv as ~1000Kv (exactly the same as the SunnySky spec.) with an Rm of 0.091 ohms. The critical “RPM as % of Kv x V” indicated that even the 11x7 GWS HD (75%) did not unduly over-load the motor .... though the temperature reached by the end of the run [50C] was a bit too hot for comfort. I entered my data into DriveCalc to obtain "true Kv", Rm, and efficiency figures. DriveCalc calculated a maximum of 75.7% efficiency at 14A.... and 68% at my suggested 30A max. Looking at my temperature data, I cannot imagine that the DriveCalc estimated max. of 45A is feasible.

Cheers, Phil

Originally Posted by Fourdan

Hi
Nothing got, up today
My bench is hungry !
Louis

Louis: we will get a new batch of motors. Samples will be sent off to you when they are available.

I really appreciate the efforts from you motor gurus

I had forgotten the X2212-9 (~1300Kv) but I got that one done last night and I'll post it later [I'm in my Lab giving a Geology exam right now!]. At the weekend I'll try to thrash the X2814-8 with some larger props.... since I test indoors I need my family and the cat well out of the way for 300W+!

Louis is welcome to all the monsters.