Rear dual NTM motor set up issue...

[Silenthunter]

I have finished my second mountain board and this time decided to use 2 NTM Prop Drive 50-60 270KV / 2400W motors. The board runs at 30 miles/h max speed and the motor get a bit warm but you can still hold it for over 20 Sec.
My only concern is the difference in outputs. The motors are calibrated and move at the same speed (no load) but the XL2 ESC show me that the left one is using only max 27.1 amps and 590 WATTS and the right one 120 amps and 2920 WATTS.

The motors are only rated at 2400W with 8S and I am only running 7S now. Does anyone know how to adjust the motors in order to get same amps compunction and power output?

For the first board I have used sk3 6374-192kv and the output was 800W vs 720W. Not perfect but close. With the NTM 50mm motors the difference is way to big 590W vs 2930W.

 

[made_in_the_alps_legacy]

some say it's a throttle range adjustement issue (which differ from 1 ESC to the other) but I am pretty sure you checked that already...

 

[Silenthunter]

I did and all settings are the same. Onloop suggested that the one of the motors is faulty.....but not sure if this is the case here.

 

[psychotiller]

Switch the motors to the opposing esc's and see if you get the same results.

 

[Silenthunter]

swapped the motors and still the same result. What else can be done?

 

[psychotiller]

Well, Since you swapped the motors, the 590 esc is the problem. The only other test I can think of is run one motor by itself on the weak esc and see if it still reads low. Then call Castle.

 

[Drevious]

Try changing your stance on the board ie flip board around or stand on other side. One motor is probably doing more work because of the load. Also you can check the tension of the belts. Could be a bad solder, bad batteries, or countless other things. If you have a multi-meter you can test all these things.

 

[Silenthunter]

Try changing your stance on the board ie flip board around or stand on other side. One motor is probably doing more work because of the load - This may be a good idea. I will try it tonight.

Tension of the belt is the same, though bout it and doubled checked couple of times.
All soldered properly, same battery used previously with 6374 and output was 800W and 720W so it is not the ESC. I will swap the wires and run it as a front drive just to see what is going to happen.

Thanks you for the suggestions.

 

[Silenthunter]

I will run one esc and see what is going to happen. Good point. Thanks!!!

 

[Silenthunter]

I swap the motors for the front drive and still same results. Tried to run one motor at the time and one of them recorder (100 meters test) 1850 Watts and cold to the touch. The second one recorded 1350W and it was hot and smelled like it got burned inside. I guess one of them is faulty and has to be replaced.

 

[psychotiller]

I swap the motors for the front drive and still same results. Tried to run one motor at the time and one of them recorder (100 meters test) 1850 Watts and cold to the touch. The second one recorded 1350W and it was hot and smelled like it got burned inside. I guess one of them is faulty and has to be replaced.

Any chance they could be wound differently?

 

[Silenthunter]

I have no idea. It was purchased from HobbyKing and it should be exactly the specs they post on the web. Maybe something is wrong with it...I just ordered a new one from ebay. Hopefully I get it soon to do another test and find the issue.

I kinda liked more the NTM vs SK3 6374. More speed and pretty close torque for much less weight. I may get better results with the new motor.

 

[Silenthunter]

Swap back to the 6374 motors and same issue is happening. One motor is pulling 5000W the other on only 400W.

 

[torqueboards]

Swap back to the 6374 motors and same issue is happening. One motor is pulling 5000W the other on only 400W.

What ESC are you using? Could be an ESC issue?

 

[Silenthunter]

I posted on top.....Mamba XL2

 

[psychotiller]

Swap back to the 6374 motors and same issue is happening. One motor is pulling 5000W the other on only 400W.

What ESC are you using? Could be an ESC issue?

Yeah, I still think it's the ESC as well.

 

[Silenthunter]

I would like to see what outputs are you getting with yours dual set ups.

I will do some more test tomorrow with different ESC and hopefully get to the bottom of this issue.

 

[Silenthunter]

Ran couple of tests today using one ESC at the time. The left esc worked at 850W and the other one at 1200W. Close but not even...
When I combined them back together the left one registered max - 3947 Watts and the right one only 403 Watts.

Have no idea why the esc's aren't working at the same values or at least closer numbers. Does anyone experienced the same issue?

 

[psychotiller]

I haven't built a dual motor set up yet so I'm not sure...You just run the esc's to one single receiver with a Y connection right? I dont understand how the esc's would be able to sense the difference.

 

[Silenthunter]

Yes, I used an Y harness. I don't have any reasonable explanation, that is why I started this thread hoping that someone that had this set up for a while does know how to properly calibrate them.

 

[rs4race]

I think you checked off the list.
Calibration and esc settings
Belt tension
Swap motors
....
Bearings maybe?
Batteries rated the same?

I have different ess, but the calibration was off including the max throttle and timing settings. I have also noticed one bearing have a lot of drag from being over tightened.

Hope you find your fix!

 

[Silenthunter]

Calibration and esc settings - connect the esc than turn the radio and perform calibration - DONE!
Belt tension - Done!
Swap motors - Done!

Batteries rated the same? - There is one battery connected for both ESC (in parallel)

Not sure if this is important but both motors have same temperature but different output.