SSunnysky Mini 0705 15000KV motor - Page 3 - RC Groups
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Jan 08, 2018, 05:58 AM
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Originally Posted by bennymack
Hi, everybody. My 0705 finally arrived and I threw them on the bench to do some testing before attempting a build and I've found something odd...

My test setup is an emax femto FC. It doesn't support 1s operation but it powers up via USB for the test just fine. Then the ESC is a RTFQ tiny ant in default configuration (not converted to 2s), running blheli_s J-L-90, 16.7. This ESC doesn't appear to support dshot surprisingly so I've just been trying multishot and oneshot. Bench power supply set to 3.8v.

So, here's the weirdness. When I use the motor test tab in the BF configurator to spin the motor without a prop, the amps go up to about 2.45 at 1600us, then go DOWN from there. WTH?! Like when it finally hits 2000us it's down to about 0.60a. When it is up to 2.45a like that, it's almost burning my fingers (I'm holding the motor down by the wires on a piece of packing foam). The motor itself isn't hot at this point though. I tried turning down the motor timing but it still behaved the same.

So is the just a weirdness of the ESC? Perhaps the firmware can't handle these? Or possibly a problem with the motor design? I do have other 1s escs to try. But let me know if there's anything to try on this setup to eliminate the problem before I tear it down.
Thats the exact same phenomena I've been observing while doing thrust tests on my test rig. 1S battery, 7A Multistar BLHeli_s ESC, SS R0705 motor, no prop - amps goes up to about 1.2A at about half of the throttle and then suddenly drops to 0.6A while throttling up. There is a noticeable sound change at this step.
I have tested 2 motors and both are acting the same.
My guess it is something with the timings of this motor.
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Jan 09, 2018, 11:45 PM
Registered User

The struggle is real.

Guys I've been REALLY struggling to use this 0705 motors to build something that flies great and is tiny. My first try was on a smaller RakonHeli brushless whoop frame and it had plenty of issues that you can read about here. Since then I've rebuilt the quad with the larger 76mm frame hoping to get a better performance.
Here's the setup:
Motors: SunnySky 0705 15000kv
Frame: Rakonheli 1S, 2S Delrin Carbon 76mm Brushless Whoop Kit (for 1103, SunnySky 0705 Motor)
FC & ESC: Tinyfish stack from GetFPV.

The quad is 32g dry and 46g with a 500mah 1S battery.

The results are abysmal. The thing wont even take off.

There are 2 thinks to take note of in this video. 1) The props don't stay on. I've opened a few packs of props and these motor shafts aren't consistent across all 4 motors. 1 consistently can't hold a prop. 2) The front-left motor stops spinning under throttle while the others keep on trucking. Especially if I throttle up quickly. It seems like it doesn't have the strength to get a 40mm prop like this going?

Tiny Whoop try 2 fail. (0 min 8 sec)

Would you guys expect that this motor would be able to spin a 40mm tri-blade prop?
Last edited by coreysnyder04; Jan 09, 2018 at 11:50 PM.
Jan 09, 2018, 11:50 PM
Registered User
If anyone has any advice on a setup that will fly I'd be pretty grateful. I've spent a lot of time and money trying to make something work and I'm getting pretty frustrated. I'm now over $100 spent on the following frames unfortunately:

Here are the frames I've purchased:
Last edited by coreysnyder04; Jan 10, 2018 at 10:57 AM.

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