Having a bit of problem and looking for any suggestion on how fix.

Trying to build up my second quad and getting power loss on all motors over 1/3 of max throttle.  In betaflight when I test the motors everything works fine until I get to over 1/3 of max throttle then they all cut out.  Noticed that the voltage readings in betaflight is ok up the 1/3 point then it drops quickly.  When I decrease throttle, the voltage reading increases and motors work again to the 1/3 level.  Have tried different batteries to no avail.

Not sure what the issue may be and really appreciate any suggestion on possible solutions. 


Updated FC firmware and ESC's BLHeli32 to latest versions.

FC - CL Racing F4S
ESCs - DYS Aris 35A
Motors - Emax 2205 2600kv
Batteries - Tattu R-Line 1550 mah 75C

Were you testing with props removed?
Were you testing with Motor tab? or radio stick?
Are you using any capacitor at the XT60 lead?

(15-Jan-2019, 05:24 PM)Oscar Wrote: Were you testing with props removed?
Were you testing with Motor tab? or radio stick?
Are you using any capacitor at the XT60 lead?

No props and tested in motor tab.  Same thing happens when I use the transmitter.

Not using capacitors on the xt60 lead or to ESCs.

Maybe there is something wrong /w the escs. Try swapping out different parts in order to find the point of fault. For example, try a different ESC, FC, Motor, etc. until you are able to pinpoint the problem. Then diagnose it accordingly. Happy FPV!

What voltage do you see before and after giving it 100% throttle?
at what voltage does it stop?
I hope you are not using an empty lipo.

(15-Jan-2019, 07:42 PM)Oscar Wrote: What voltage do you see before and after giving it 100% throttle?
at what voltage does it stop?
I hope you are not using an empty lipo.

I have make sure the batteries are charged and have tried a few different one.

At 16.6 V before giving it throttle and it drops down to around 5.7 V immediately when I get above a third throttle.  The voltage values fluctuate all over the place after the motors cut out when the throttle is still above 1/3.  Once I bring the throttle back to 0 the voltage stabilizes back at 16.6 V.

Thanks for the suggestions.

definitely sounds something is wrong with the hardware.
are you using 4 single ESC's? or a 4in1 ESC?

I suspect one or multiple of the ESC or motors have a problem.

first of all, check motor screws are not touching windings: https://oscarliang.com/check-motor-screw...g-winding/
Then check if your ESC, or any solder joints / wires are touching the carbon fibre frame.

If all is fine so far, check your ESC's. If using single ESC's, remove the power on any 3 ESC's (so ESC and motor won't get power), leaving just 1 ESC connected to power. Now try to run the motor again, see if you have any problems? Now remove that ESC power as well, and try a different ESC, until you have gone through all 4.

If you can narrow down to a particular ESC and motor combo that has problem, you can try again after swamping around the motor, to find out whether the problem is from the ESC, or motor.

Thanks Oscar.

It ended up being the FC, tried and old one with the ESCs and it worked.

Really appreciate the help.