Motorsync test-----Failed/ Which ESCs work?

Hardware Multirotors
1

And I thought I would be immune to the sync issues…
Tarot 690s hex
SunnySky 4108s
ESC RoHS 30 amp opto mounted beneath motors with SimonK fw
Pixhawk

I finally finished building and persued a backyard very low alt test hop with stabilize Alt hold and loiter which all looked fine. With small roll stick pumps, motors growled and the hex fell, no damage…

Motorsync test with inverted props failed with growl at 75% throttle…

I have seen tons of posts with the sync issues with auto tune with SimonK FW but I am not aware of a workaround.

Suggestions greatly appreciated…

2

I asked this on another forum I think.

There are less chances of de-syncing if using a non-SimonK ESC.

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3

I have the same setup as you. Have not built it up yet. Waiting for exams to be over.

I think I will just tune it manually.

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4

I would like to be able to manually tune it but it just leans over with the de-synching with any kind of rapid throttle change like gentile roll with quick return to center stick… I can really see how AT is not possible… Anyway, grounded for now…

5

I think its safer to just change to non-simonk esc’s then.

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6

Yep, non-SimonK ESCs work just fine… I am using HobbyWing 30 Platinums…

7

Thank you sir! Will get some once my exams are over…

8

Hello. I’m experiencing a very similar problem
My config:

  • Pixhawk with arducopter 3.4.5
  • Hobbywing X-Rotor ESC - 40amp (OPTO)
  • T-motor Antigravity 4004-400KV
  • 6S battery

With 4S battery everything (motor test + flight) is smooth and OK.

With 6S any motor test above 50% will deterministically cause any of my 6 motors to loose sync.
Additionally, with 6S when arming occasionally one of the motor looses sync, and during flight the behaviour of the motors “sounds” sometimes rough.

I guess this may be connected with the rate of change of the PWM command sent to the ESC.
For example, during motor test it suspect it goes abruptly to the target percentage (I will check with an oscilloscope when I’ll have a little time). On the contrary, I activate ESC tuning, and feed the radio PWM directly to the 6 motors, no matter how fast I move the throttle stick, there is no way to have a sync problem and everything is smooth even with 6S.

Is there any way to ease-in the new ESC PWM value(s)? Like a low-pass filter, or something?

9

All the sync prtoblems I’ve had so far have been caused by dodgy bullet connectors.The ones that have a cage on the male allowing it to spin.I’ve found them to be excitingly unreliable.I either solder the cage to the bullet or remove them entirely and solder the wires.Got to be worth a check.I’ve had three fail like this recently and had similar symptoms.Two on the ground and one in the air.It’s now the first thing i check on a copter at the slightest lack of sync.

10

Hi @Jagger .
Thank you for your reply.
Indeed, my motor cables are soldered to the esc-I’ve passed through the dodgy bullets before :slight_smile:

11

Ah right.It leaves an impression I found.In the ground sometimes.it was worth a mention. :slight_smile: