3 crashes in 1 flight : need your help guys !!!!

Hi all,

Well today I went for a test flight, trying to get my octocopter under control because I have an important demo to do on Saturday for a potential client. It did not go as expected. Here is my config :

- RCTimer F1000 Cinestar Clone

- RCtimer HP4108 380KV motors

- RCTimer 40A ESC (SimonK)

- 14x4.7 carbon props

- APM 2.5

- 2 x 5800 Zippy 6S

- Brushless gimbal + 1 5000 3S for power + 1 gopro

The first 2 crashes happened like this : I'm flying at about 10 m high and lower my throttle, the copter goes down slowly and at 3 meters or so I'm going full throttle with absolutely NO effect. The copter just crashed on the ground. 2 times. 1 crab leg broken. 

I'm going up in the air for a third time, then this time it starts spinning like crazy then crashes. 1 prop broken. 

So please, take a look at my logs as I cannot understand what is going on. As one would expect, I'm really frustrated because it's not the first time the APM gets out of control and I break stuff. 

Thanks in advance for your time guys !


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  • After finding out about this, I think it could be related to a crash I had a while back using that same ESC (RCTimer 40a SimonK) with sunnysky 4112 320kv motors. The heli would spin rapidly while completely unresponsive to my commands, then flip upside down and fly into the ground. It was not pretty.

    What is the best way to check motor - esc compatibility? 

    I'm planning on using 4108 380kv motors with dji 30a esc and 4s packs, would this be a problem?

  • Hello,

    Had issues on u8 motors and simonk rctimer esc. "Pop" noise changed back to my favorite tmotor 40A and all ok!

    A bientot.
  • Moderator

    Hi Cirilo ,

    the problem is classic resync problem . It was present also on T-Motors 3506 - 08 . 

    It is solved in last revision of SimonK firmware that try to manage resync problem.

    You cound found this problem in this way : 

    Fix your drone to Ground in better way ... arm it , and start to doing gas up and down fast ... if you solve resync problem the motor follow throttle command. If not you can also burn an esc keep atention ...

    There are some video online also one from Marco Robustini where you can see this problem.

    this is the link :  https://www.youtube.com/watch?v=0lRTN5o4UCM



    • Please can you moderator/developer guys start a thread that gives information about what high pole low kV motors work with what ESC. There are a lot of information out there but no concrete answer for what ESC and 6s work with what pole/kV.

    • Thank you all for your answers. My problem was due to a faulty motor, I changed it and now everything is working perfectly. I don't seem to have any issues with resync though, but will keep an eye on that. Any hints on how to detect this kind of issue ? 

      • What kind of fault it had?

  • I am using HK Turnigy Plus on my quad, never had problem, never flash this ESC, why do you want to flash it?

    • To make it better? But if the original software in the plush 40a can handle 22pole and 6s at 380kv with good throttle resolution there is no need. I ordered the multi star 4108  a few days ago NAD start reading about those sync issues. With simonk.

      • 40A for the 4108?

        I fly them with 4S since one year with 20A Multistar Opto in a 7kg OctaQaud wthout any problems. The ESC never come over 50°C.

        • 40a is smalest esc with 6s

          I'm still looking for an anwser if somone flies these plush 40a wit h6s and 380kv motors without problems.

This reply was deleted.


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