I have 4 arducopter ESC 20A and 4 motors (850kv, A-2830/12). Power is coming from a power supply 12V 2250mA. The input (white wire) of the ESC is connected to my arduino (pin 9) and the ground (black wire) to the gnd of the arduino. I use the Servo library and send a minimal signal (700) for a few seconds and then start sending bigger values.
Sadly the motor only stutters, it never really turns. It does that for all combinations of motors and ESC I tried.The ESCs always make the correct little sounds at the beginning.
There are many things I had to solder and I am wondering if it could be a problem with the solder joint ? It was the first time I soldered anything. I watched many videos to see how to do but I have no experience at all. The circuit is as follow and everything with a * was soldered by me:
Power plug jack == jack to Deans* == Deans* to ESC to plugs* == plugs* to motor
1. Do you agree that it most certainly is a problem with the soldering ?
2. Do you need more information, or even a video, to help ?
3. How to know which solder joint is bad ?
I have built a few copters now, I had this issue on one of the very first ones i put together, there was a poor solder connection to the motor from the ESC, the motor would "chatter" away and not spin! This was some time back now, there was a recommendation to remove all the "connections" between the PDB ESC Motors, so you solder each point not use a connector, after I did this the fault was gone, motor worked fine :) I now build all copters without the connectors and solder each and every point from the PDB to the ESC to the motor, not had another motor "chatter" from that day!!
Please take the three wires from that motor and solder direct to the ESC's wires, let us know how you get on :)
Thank you very much for your quick reply.
I will proceed as you said and solder the ESC directly to the motor.
I'll keep you posted !
I'd try running from a 3S LiPo battery rather than a power supply.
The scenario is probably this. When your motors are starting, they will briefly draw a fairly high current (more than 2.25A) to get them going. Your power supply will go into current limit which will momentarily shut down the power causing a brownout to the ESC which will then do a restart. It will then try to start the motors again, causing a current limit ... etc.
I have soldered the ESC directly to the motor and it runs ! :)
I tested with the power supply and with the battery 3 cells lipo.
*However*, it does shut down if I try to run it too fast. When it happens, decreasing the speed doesn't make it restart,I have to send again a minimal signal before I can get it turn again.
Could it be another bad connection ? something else ?
Thanks a lot already for your valuable help.
That's because the power supply is browning out, so the ESC thinking it's a battery must protect against over discharge and shut down to not kill the battery. This is all normal operation.
It's working exactly as it should, but your supporting hardware for the test (namely the power supply) is not up to the task. You need to test with a real battery.
I understand this now.
I have tested with my batterh (http://www.conrad.ch/ce/fr/product/209050/LIPO-FLUGAKKU-111-V-2500-...) and I got the same.
It might be that the battery was already quite empty. I will fill it up and try again.
Cheers for your help and kindness !
A stuttering motor is normally one wire (not two) with a connection problem, sometimes it's inside the motor itself but often just as the wires go into the motor housing where chafing or vibration or movement causes a break. On certain motors I put a dab of epoxy on the wires just as they come out of the motor to immobilize the wires and prevent a wire break at that point. Years ago I had a new Axi motor that had an invisible internal wire break that was intermittent.
Most ESC's will stutter as they try to start the motor but on occasion if the motor starts and then the connection becomes intermittent again the ESC will shut down and no longer provide power to that motor requiring a return to zero throttle before it'll start again.
Sounds like there's still a connection problem even after you've soldered the wires.
Just as an aside, don't let a LiPo get 'empty'. Anything under around 3v a cell will kill or permanently damage the battery, and a damaged LiPo is dangerous.