Motors running too hot!

[slasher]

Hey guys, so after some struggle trying to get my tricopter to fly, it seems my new main issue is my motors getting burning hot, especially the tail motor, so hot that they start to melt the 3d printed motor mounts :/

the motors I’m using are generic 1000kv motors from ebay, and some 30A esc’s flashed to the latest Simonk firmware. I have done the usual hot motor checklist, there are no screws touching winding, the motors move freely, i am flying quite docile and my pids are not too high. I have also tried a BLheli esc with these motors and they get just as hot. the only thing left for me to try is a different prop size, I’m currently running 1045, I have some 9045 coming in tomorrow that I hope will help. Thanks

[biggestRCEfan]

I would guess the props are not compatible with the motors.

[rc468]

What battery are you using? 1045 might be too heavy for 1000KV motors, but you should show them or write their full specs to get a solid answer. If you have OSD and current sensor, you can also check the amperage value in flight.
Also check the screws in motor mounts and/or overall frame stiffness. If they are not tight, motors might vibrate causing controller to change speeds very fast, that will lead to heating. I’ve had such issue on my tricopter.

[slasher]

@rc468 I am using a naze32 rev6, triflight firmware and a 4200mah battery (but the battery needs to be returned because its last not as long as my 2200mah). I just got 9×4.5 and the temps have gone down slightly, I can now comfortably hold the front two motors after flying, but the tail motor is still too hot to hold after flight, I also notice a tail wag from the servo which might contribute to the heat?

[Kevin_Erik]

Incorrect Gyro, Notch-filtering or excessive PID gains can easily cause the motors to overheat. Default your copters settings and see if it still does.

Weight distribution can be an issue if the battery is too far from the Center of Gravity. Then one motor will be supporting the extra load instead of sharing it between all three. If your Blackbox logs always show one motor as spinning significantly faster and drawing more current than the others, it’s most likely a weight distribution problem. This means that your copter will have to provide constant corrections to maintain it’s orientation. Thus your motor has to work much harder than normal.

Plug your copter spec’s into E-Calc as it can tell help you estimate the performance and loading your copter may experience in flight. This can help you figure out if the Motor / ESC / Battery combination your using is appropriate. https://www.ecalc.ch/xcoptercalc.php Keep in mind that Davids V4 Tricopter uses an 8x5x2 Propellers with 2217-1300kv motors. Like BigRC said, you could be oversized or over pitched.

As for your Tail-Wag try using the Impossible Tail Mechanism: https://www.thingiverse.com/thing:1035497
Those seem to help allot by reducing the amount of rotational motor mass that’s being moved from one side to the other. All that mass movement is causing the copter to Roll unexpectedly which in turn causes the copter to attempt to correct for the Roll. This ends up creating a feedback loop producing the oscillations / Wag your seeing.

[slasher]

@Kevin_Erik Thank you for your help, I will look into the Ecalc and check my black box. Previously my servo was mounted behind my tail motor, ive move it in front of the tail motor, put 9×4.5’s on and lowered my I gain for the yaw and its seemed to help lower the heat considerably. I’m actually using that current tail mech, I actually modified it for use with a full-size servo.

The second photo was the old servo method I had, at the time it seemed like a good idea, but it added too much wait to the tail arm, and cut more of the air off from the tail prop.

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[Kevin_Erik]

Are your motor arms wood?
You could use carbon arms as they are much stiffer and often weight less.

[slasher]

@Kevin_Erik yeah, they are wood. its my first tricopter build so I wanted to go inexpensive because I knew i would crash it often XD. that being said, I hear wood is pretty good

[Kevin_Erik]

Carbon with wood inserts is all but unbreakable and very very stiff.

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