Faulty jDrones ESC?

Hello everyone!UAV/quadcopter newb here. Although not a (complete) RC/microprocessor/programming newb.Anyways, finally got all the parts needed and started assembling my arducopter this week, decided to go through all the motors and ESCs (to check and program them before assembly) and on the very last ESC i've hooked up to the receiver i got this:http://diydrones.com/video/failing-jdrones-escThe hiccups are at about 25% throttle. The jerky transition is at 50%. The fluctuations are at 75-100%. I'm pretty sure the issue is with the jDrones ESC, because:1) i've tried other motors - same deal2) i've tried this and other motors on other ESCs - works just fine3) i've tried resetting it, as well as different timings - same deal3) the ESC in question is practically soldered directly to the battery power - it's the closest one to the batt. wires on the PDB.Will try resoldering the bullet connectors on the ESC as a last resort, although they seem solid enough and jiggling them about or pressing them doesn't create any changes in the motor behaviour.And just as i was about to finally assemble the frame... *sigh*

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

Join diydrones

Email me when people reply –

Replies

  • Just a tiny update...

    jDrones responded to the support ticket and are sending a replacement tomorrow, so yay! :)

    Meanwhile, i've got two 30A Hobby Wing Pentiums which i'm going to hook up to the front and rear motor, while driving the left and right with the good jDrones ESCs.

    The Hobby Wings have identical menus and settings, although the software (and hardware) quite obviously isn't exactly the same. Probably same OEM. They drive the jDrones' smaller outrunners noticeably more smoothly than the jDrones ones. I still have to check if the throttle curves / RPMs are comparable, but i'd say they are.

    If the mix proves troublesome when i get to actual flight and PID tuning, i'll revert to all jDrones ESC configuration. Especially if it turns out the input of the HW Pentiums is too filtered / response too slow. If not, i might eventually switch the remaining two jDrones ESCs for 30A Pentiums.
  • Still no response from jDrones to my support ticket...
    Not exactly the most responsive bunch, are they? ;)

    A local shop has some Hobby Wing ESCs.
    After checking the functions, specs and manuals for HW Pentium and jDrones ESCs (as well as some Alibaba.com OEM listings), i'd say they're from a same OEM, even despite the slightly different current ratings.

    Think i'll hazard buying one and checking how it behaves in place of the jDrones one.
    If things pan out - good.
    If not, i have a spare for my traditional heli, or i can get 3 more and replace all the ESCs.

    The waiting's killing me...
  • Hmmm. Additional symptom i've noticed.
    The throttle response curve on the afflicted ESC is wacky.

    It's like 0-15% throttle is linearly mapped to (very jerky) 20% RPM, then there's an exponential bump at 20-25% throttle to 50% RPM, then a linear ramp from 25%-60% throttle to about 80% RPM and then a sudden bump at 75% throttle to 100% RPM. Then a big nothing from 75%-100% throttle.

    And yes, i have calibrated it, multiple times.

    I've also noticed the fluctuations at higher RPMs don't go down, but up!
    Could this be some weird PWM frequency incompatibility?
    http://wacky.It/
  • Small update: resoldered the bullet receptacles and, just to be sure, the + and - wires on the PDB. Same thing. I'm running out of ideas...
This reply was deleted.

Activity

DIY Robocars via Twitter
RT @chr1sa: Donkeycar 4.4 released with tons of new features, including path learning (useful with GPS outdoors), better Web and Lidar supp…
Sunday
DIY Robocars via Twitter
RT @NXP: We are already biting our nails in anticipation of the #NXPCupEMEA challenge! 😉 Did you know there are great cash prizes to be won…
Friday
DIY Robocars via Twitter
RT @gclue_akira: レースまであと3日。今回のコースは激ムズかも。あと一歩 #jetracer https://t.co/GKcEjImQ3t
Friday
DIY Robocars via Twitter
UC Berkeley's DIY robocar program https://roar.berkeley.edu/
Friday
DIY Robocars via Twitter
RT @chr1sa: The next @DIYRobocars autonomous car race at @circuitlaunch will be on Sat, Dec 10. Thrills, spills and a Brazilian BBQ. Fun…
Friday
DIY Robocars via Twitter
RT @arthiak_tc: Donkey car platform ... Still training uses behavioral cloning #TCXpo #diyrobocar @OttawaAVGroup https://t.co/PHBYwlFlnE
Nov 20
DIY Robocars via Twitter
RT @emurmur77: Points for style. @donkeycar racing in @diyrobocars at @UCSDJacobs thanks @chr1sa for taking the video. https://t.co/Y2hMyj1…
Nov 20
DIY Robocars via Twitter
RT @SmallpixelCar: Going to @diyrobocars race at @UCSDJacobs https://t.co/Rrf9vDJ8TJ
Nov 8
DIY Robocars via Twitter
RT @SmallpixelCar: Race @diyrobocars at @UCSDJacobs thanks @chr1sa for taking the video. https://t.co/kK686Hb9Ej
Nov 8
DIY Robocars via Twitter
RT @PiWarsRobotics: Presenting: the Hacky Racers Robotic Racing Series in collaboration with #PiWars. Find out more and register your inter…
Oct 23
DIY Robocars via Twitter
RT @Hacky_Racers: There will be three classes at this event: A4, A2, and Hacky Racer! A4 and A2 are based around UK paper sizing and existi…
Oct 23
DIY Robocars via Twitter
Oct 23
DIY Robocars via Twitter
Oct 19
DIY Robocars via Twitter
Oct 18
DIY Robocars via Twitter
RT @NeaveEng: Calling all UK based folks interested in @diyrobocars, @f1tenth, @donkey_car, and similar robot racing competitions! @hacky_r…
Oct 13
DIY Robocars via Twitter
RT @araffin2: 🏎️ After hours of video editing, I'm happy to share a best of my Twitch videos on learning to race with RL. 🏎️ Each part is…
Oct 13
More…