CW Motors Overheating While CCW Stay Cool

According to the Mission Planner logs, the outputs of motors 3 and 4 are double that of motors 1 and 2. Consequently, motors 3 and 4 quickly overheat.

3691103377?profile=original

I'm trying to get my new multi dialed-in but after only 5 minutes of hover attempts [at about 45% throttle] both of my CW-rotating motors (3 & 4) get so hot you can't touch them, while the CCW motors remain cool. All calibrations have been re re re re re-run. ESCs, radio, accelerometers, compass, and everything appears to be balanced — fore-aft CG, props, etc. — yaw seems stable, I even disassembled the motors, balanced the bells, lubricated the shafts and bearings with EPIC oil for electrics (note that these motors are new and have less than 15 minutes run time on them).


To make matters worse, This is only the third real attempt to get a stable hover but I can't quite get there from here. I still require manual trim input on the Tx of about 5% right roll and 5% up pitch for it to behave as well as it does in the video. I'd love for it to be rock steady but I'm not sure know how to get there and with two overheating motors there's no way I'm going to attempt to fly outdoors.

I have an email in to HK tech support but no reply yet.

If anyone is interested the video is here and sample log files are here:

2014-03-09_2015-26-22.log

2014-03-08_2015-17-29_2062807.zip


For safety, the skids are covered in foam pipe insulation and a prop protector stick was added to each arm (the sticks are from 2 carbon fiber arrows -- $3.50 each at Walmart).

And yes, the props are right-side up =)

Specs

===================================

Frame: Tarot Iron Man 650

Arducopter: 3.1.2

Props: APC 12x4.5

Motors: NTM Prop Drive 28-30S 800KV

ESCs: Turnigy Plush 40A

Battery: Turnigy 40C 5A 4S

Flight controller: APM 2.6 w/uBlox GPS

Receiver: FrSky D8R-II PLUS (modified antennas)

Transmitter: ER9X with FrSky ACCST 8CH module

Weight as shown: 2.4kg

Thanks!

My current PID settings:

3691103391?profile=original

2014-03-09 15-26-22.log

2014-03-08 15-17-29 62807.zip

You need to be a member of diydrones to add comments!

Join diydrones

Replies are closed for this discussion.

Replies

            • I looked at your motor outputs and they are very different from my own.  Your motors appear to be all working at similar levels but still quite different -- are you able to maintain hover with stick inputs? Or is it constantly fighting you?

              • i manage to maintain hover but as pid are not good for now, it moves a little.

                • If you're only drifting a little and it's not oscillating then I would think you're ready to try Autotune to tighten it up.  

  • Quite a conundrum eh?

    Frame twist could be an issue but, to demand so much more drive? Seems unlikely.

     -- Could the problem be the converse...Motors 1 & 2 not pulling their share forcing 3 & 4 to overwork?

    I can buy one ESC acting up but two, on the same rotational plane?

    OR

    -- Is it possible that you have the APM -> ESC wiring crossed up and fixed the direction with motor wiring exchange?

    3701681214?profile=original

    In other words, you have M1, M3, M2, M4 wiring at M3, M2, M4, M1 and set the rotational direction with the ESC -> Motor wiring?

    When you have eliminated the possible, all that is left is...

    -=Doug

    • I re-checked the wiring and the outputs of the APM, 1 2 3 and 4, are correctly connected to their corresponding ESCs/motors.

    • I'm intrigued. My copter is setup as an X and it flies like an X but as you posited, motors 3 and 4 seem to be doing the lion's share of the work. If the above were the case would I still get normal responses to control inputs?  Aside from the weird overheating it reacts to inputs as you would expect.

  • Are your CW props mounted the correct way? This may explain why they need to work harder to achieve the same thrust as your CCW motors which most likely have their props mounted correctly.

    EDIT: Doh! Nevermind. Didn't see your last sentence "And yes, the props are right-side up =)"

    I only mention because the same thing happened to me a few years ago and that was the issue. Nice looking quad btw.

    • Despite the previous post and with apologies I'll still mention props - we've seen so many times how easy it is to have a problem with that. Check again that you actually have left and right rotating props on left and right rotating motors, and that they really are right side up ... I know, I know, it sounds lame...

      • Third set of props. All balanced right down to the hubs, and yes, they are on correctly.

        • 3702750199?profile=originalI think you might be underpowered.  600-700 on throttle just to barely make liftoff seems like too much.

          Try lightening the load.

This reply was deleted.

Activity

DIY Robocars via Twitter
yesterday
DIY Robocars via Twitter
RT @SmallpixelCar: @a1k0n @diyrobocars I learned from this. This is my speed profile. Looks like I am too conservative on the right side of…
yesterday
DIY Robocars via Twitter
RT @a1k0n: @SmallpixelCar @diyrobocars Dot color is speed; brighter is faster. Yeah, it has less room to explore in the tighter part, and t…
yesterday
DIY Robocars via Twitter
RT @a1k0n: I'm gonna try to do proper offline reinforcement learning for @diyrobocars and throw away all my manual parameter tuning for the…
Friday
DIY Robocars via Twitter
RT @circuitlaunch: DIY Robocars & Brazilian BBQ - Sat 10/1. Our track combines hairpin curves with an intersection for max danger. Take tha…
Thursday
DIY Robocars via Twitter
RT @SmallpixelCar: Had an great test today on @RAMS_RC_Club track. However the car starts to drift at 40mph. Some experts recommended to ch…
Sep 11
DIY Robocars via Twitter
RT @gclue_akira: 世界最速 チームtamiyaのaiカー https://t.co/1Qq2zOeftG
Sep 10
DIY Robocars via Twitter
RT @DanielChiaJH: Always a good time working on my @diyrobocars car at @circuitlaunch. Still got some work to do if I’m to beat @a1k0n howe…
Sep 10
DIY Robocars via Twitter
RT @SmallpixelCar: My new speed profile for @RAMS_RC_Club track https://t.co/RtLb7TcgIJ
Sep 10
DIY Robocars via Twitter
RT @SmallpixelCar: Practiced at @RAMS_RC_Club today with my new @ARRMARC car https://t.co/AEu2hCx89T
Aug 28
DIY Robocars via Twitter
Aug 24
DIY Robocars via Twitter
RT @gclue_akira: 柏の葉で走行させてるjetracerの中身 #instantNeRF #jetracer https://t.co/giVvuE4hP7
Jul 4
DIY Robocars via Twitter
Cool web-based self-driving simulator. Click save when the AI does the right thing https://github.com/pncsoares/self-driving-car
Jul 4
DIY Robocars via Twitter
RT @donkey_car: Human-scale Donkey Car! Hope this makes it to a @diyrobocars race https://www.youtube.com/watch?v=ZMaf031U8jg
Jun 25
DIY Robocars via Twitter
Jun 25
DIY Robocars via Twitter
Jun 16
More…