in case no one signalized this yet here and Jani or other AC makers wouldn't know: many people seem to be having problems with the ESC to motor connectors supplied with the jDrones ArduCopter Kit (checj here or here). I crashed my AC about 4 times before I found the right thread on DIYDrones and found out the cause. Luckily 3 out of 4 of those I flew on very low altitude over grass, so nothing really bad happened (I lost a motor, one arm, upper dome center and a couple of propellers because of this, APM and Oilpan survived).

I think those shouldn't be supplied with the kit as they cause temporary lack of current up to the point when the connection is out for too long and a motor stops in flight, which causes a flip and a crash eventually.

Is the problem officially known already?


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  • Developer


    Yes it has been discussed here earlier and generally we advice people to solder those wires directly. Sure you can use connectors first to find out which way you need to connect your cables but after that you should solder them or secure them other way to avoid connection problems.


    Originally bullets were soldered to cables to make assembly easier but after we saw problems with some of our users, bullets were removed from cables and they are now in accessory bags for people who want to use those.


    Many people are using those without problems including me on some of our test units but yes some connectors might have problems if they are not secured tight enough. So advice is, Don't use unless you really need to use those, if you use after checking motor rotation, add solder to secure connection.


    I will look our build manuals to make this more clear over there.

  • hi
    the problem with the bullet connectors is well known. search for bulletconnector and you'll find a lot of " flips " and grilled motors. solder at least the bullets - or better : replace them.

  • Tom

    An alternative explanation for this bad behaviour would be that the 5V power supply to the AMP / RX etc is interrupted or 'browns out'.

    This could cause the APM board to send bad signals or no signal to the ESC's which would then cause them to reset and you get the same motor stop, flip and crash.

    What are you using as a power supply to your APM and RX?

    If it is the BEC in one of the ESC then the recommendation in numerous posts is to replace this with an external UBEC or other power supply.

    I have done this and no longer suffer from any motor stops or ESC resets using an otherwise standard arducopter kit from jdrones, with bullet connectors.


  • 3D Robotics
    You're referring to the bullet connectors from the ESCs to the motors? There was a problem with some of the early kits (low quality connector) but as far as I know the more recent ones are fine (I've got one). Can you say more about what the problem is and when you got the kit?
  • Your kit came with motor connectors? Mine didnt, so I just soldered them.

    Havnt had any problem though except once when a motor cut out very high and re-enabled before it hit the ground where stabilize mode saved the day =)
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