Think about an electric motor for your 5 (or maybe even 6) inch acro or FPV racing quadcopter. What do you see? Something in a 2205-2306 size range with a KV rating somewhere 2300KV and 2600KV. Sometimes even more. And it works great, as long as you wat 5-inch props and 4S batteries. You can choose and choose and choose between different models of different manufacturers. But what if you want to go 6S or 7 inches? You have a problem. Very limited choice of motors (and propellers as well).
Luckily, it starts to change and you can actually but lower KV 220x and 230x motors. I got my hands on EMAX RS2 2206 1600KV since I'm not very happy with TBS Endurance I'm using on my 7-inch endurance drone. They seem to be missing some torque and when I've found that new low-KV (1600KV is still a lot) EMAX motors, I did not waited long to order. I love RS2205S and RS2306 and hope RS2 will not disappoint me.
What can I say about EMAX RS2 2206 1600KV before installing them on anything? (so far I got only 2, the second pair is on a way)
They finally changed those plastic boxes to something smaller
RS2 2206 1600KV look good for sure. Black and Red!
No bottom cap since, well, you do not really need it after all
29g with wires
4mm shaft made from titanium (at least they say so)
Bearings are 8x4x3 if I can measure
They kept this nice screw in the bottom instead of a c-clip
Mounting holes spacing has changed! Instead of a standard 16x19mm it is 16x16mm now! Check your frame. The great majority should accept 16x16mm but there might be some rare ones that will not!
Single wire winding. Looks ok, TBS Endurance has a nicer winding tho!
Half a year after first tries (failed) to wind a DIY motor from Banggood (it's not in offer any more BTW) I gave it another try. This time, with new tricks in my sleeve and new ESC. It ended up, well, watch the video…
Is it worth to soft mount flight controller? Are gyro pads I recommended here better than rubber standoffs? I feel that they are better, but I do not have any solid data to prove it. So I can only tell, that I find them better and that is all. But, I can answer the question is it worth to soft mount flight controller at all. The answer is YES and here is a proof…
The problem of twitching motors
After I updated my 5" racer to stronger motors (EMAX RS2205S 2300KV over RS2205 2300KV) I noticed something very very irritating: twitching motors. When the throttle was in more less middle position or after rapid throttle change, twitching from motors was very audible. Quad was flyable, but performance was very low. I had to reduce yaw P gain by more than 50% not to see those twitches in FPV footage!
Blackbox log revealed the truth: from time to time, the strong vibration was getting into yaw gyro traces. I also localized the source of those twitches: stronger motors with more torque and higher radial acceleration were able to shake the whole machine when the frequency was close to the resonance frequency of the frame.
In total, I tried to wind this motor 6 times. In every single case it ended in the same way: one of the phases burned. So, it's either me, or this kit. I've verified winding directions and termination schema for at least few times, and if I didn't missed something extremely obvious, I did it in a right way. I even verified winding directions during "unwinding". So I start to suspect, that this motor is either no 12N14P DLRK (not very probable), or it should not be winded with 0.42mm wire. Next week I will order 0.20mm wire and try one more time…
This is a winding schema I used:
Poles goes as follows: AabBCcaABbcC where capital letter is clockwise, while small letter is counter-clockwise.
Phases were connected like this:
Sure, I could have done something wrong. But not 6 times in a row…
Just like it was expected, my first attempt to wind a brushless motor (12N14P) was a failure. Probable cause: short circuit between phases and my creation released magic smoke.
Then I tried for a second time, and failed again. This time less, no smoke, but motor overheats and does not want to start most of the time. I suspect this can be an ESC problem (Emax 30A) that is configured for DampedLight. Perhaps motor is rotation too fast (no load after all) and ESC tries to slow it down. Hard to tell. Tomorrow I will add a propeller and disable DampedLight. Maybe it will help. I will also try WYE configuration. Right now phases are connected in Delta setup.
As you can see on a picture above, it is a motor that you have to assemble by yourself. Wind the coils, install bearings, learn the difference between Delta and Star configuration, and so on and so on… Oh, and there is absolutely no manual. So even number of wire turns is a mystery. I suspect something around 10, but who knows.
Tomorrow will be the first attempt to assemble it. I hope magic smoke will not appear…
Hey, don't leave yet, there is more!
Do you know that there is a YouTube channel with awesome, drone and FPV related video? Why don't you give it a try?