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Sep 26, 2016, 12:13 PM
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Any tricks to using servo tester to test rc car sensored ESC with reverse?

I am helping my buddy with a hand dolly for moving his full scale competition sail plane.
I gave him a 30A ESC and we tested it in my shop and it worked great, add a cell, up to 6S, to get max speed and torque to match his needs.

That was proof of concept. Now he is using a CAR ESC with reverse and full speed forward is too slow, it is as if he can't get max forward range.

He is coming over tonight with the dolly and wants me to help diagnose it. I know nothing more than above, no brand, no amp rating, no max cell rating...

I gave him a cheap servo tester to run it and he fancied it up on the handle of the dolly and my guess is he will continue using this.

Is there a trick to this? Such as setting end points or how to know where off is and not be in reverse or forward?

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Sep 26, 2016, 01:47 PM
I am a nice guy! Really!
It def sounds like you have a throttle calibration issue. You will have to find out what speed controller it is and then find the throttle calibration routine for it. Hopefully he has the user manual with the ESC.
Sep 27, 2016, 12:00 AM
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OK. We tried setting the esc with his Hobby Wing programmer and then set the neutral, full forward and full reverse using the servo tester.
Same results.

The motor has decent slow speed control but nothing fast. It seems like it is only hitting around 10% throttle and our setting changes made no difference.

I tried a 6S pack instead of a 4S and no difference.

We then tried my Turnigy 30A ESC that I originally set it up with and we have full speed and full throttle range.

The drive wheel is from china and like an Amigo mobility scooter type wheel/motor.

The hall effect has 5 wires and the ESC has 6 wires. He tried every combination till he found 5 matches but that leaves 1 ESC wire not connected.

I failed to take a pic of the wheel/motor/hub but it is sealed anyhow so maybe it don't matter?

We quit for the night but are convienced he did not burn the motor up.
Maybe next time I will restore factory defaults and work oit from there.

The reason he is using this ESC is because the airplane ESC had bery little slow speed control and it stalled. As we know, a sensored ESC has better slow speed control and torque.

Another thing I can try next time is a better ESC like a CC 100 ICE. I have the programming card and also sw to program it easier than stick programming.

Any other ideas? Kick me left or right on above but try to not beat me down.

Sep 27, 2016, 03:01 AM
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I see that setting "9" in the manual is reverse force. The options are 25% or 50% with a default of 25%. Is it possible that the signal range you are using is reversed? I would expect that the neutral would be at about 1500 microseconds (1.5 milliseconds) and full forward would be 2000 microseconds with braking and reverse utilizing 1500 microseconds to 1000 microseconds. You may have to use option 6 to reverse the motor direction of rotation.

There are two status LED's that will flash in various combinations if an error occurs. (section 07 of the manual) are any of the flash codes flashing?
Sep 27, 2016, 09:27 AM
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No codes flashing, just normal flashes.

Is there a possibility of the motor not being compatible with this ESC because of the sensors?

We also tried hooking it to my Spektrum RC truck receiver and the full power was the same, I did not expect that. We did not set the neutral and reverse on my radio but assumed (oops) assumed it would not matter.

Mike, I appreciate your efforts on this. Usually it's me helping people with batteries so I know and appreciate your efforts.

Sep 27, 2016, 09:46 AM
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Originally Posted by rampman View Post
No codes flashing, just normal flashes.

Is there a possibility of the motor not being compatible with this ESC because of the sensors? . . .

If the sensor was not working I think you would get the red and green single flash indicating that.

Link to the online manual:
Sep 27, 2016, 12:17 PM
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The LED's flash normally. We have no error flashes, just normal flashing.
We have the manual too and factory digital programmer.
Sep 27, 2016, 07:10 PM
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Buddy sent this today and I think he got it from the ROAR site.
Sensor connection requirements:
The motor must use a six-position JST ZH connector model number ZHR-6
or equivalent connector with 6 JST part number SZH-002T-P0.5 26-28 awg.
contacts or equivalent.
Wire sequence must be as follows: -
Pin #1 - Black wire ground potential
Pin #2 - Orange wire phase C
Pin #3 - White wire phase B
Pin #4 - Green wire phase A
Pin #5 - Blue wire temp control, 10 k Thermistor referenced to ground potential
Pin #6 - Red wire + 5.0 volts d.c. +/- 10%.
Compatible speed control must use the 6 position JST header part number
X-6B-ZR-SMX-TF (where the X denotes the style of the header), or equivalent.
The motor power connectors have to be clearly marked A, B, C.
A for phase A. B for phase B. C for phase C
It is not mandatory that sensored Speed Controls have to be used, or that
the sensor ‘harness’ has to be connected.
As you no doubt figured out by the time you've read this far, the unused wire was/is the temp sensor, which the wheel doesn't have...
He continues:
Do you think that the ESC might read the unused temp sensor wire as a high temp (I don't really understand how a thermistor output is used), and automatically limit the current to ridiculously low value??
Note: All sense wires are black.
Maybe this sensor needs to go to ground? We do have an extra wire but no schematic for the ESC showing the pinout of the small 6 conductor connector.
My guess is to run that wire to battery ground. Heck, I guess we can't hurt it much. LOL

Sep 27, 2016, 09:36 PM
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The thermister would be a nominal 10K unit. That means it is 10K ohms at around room temp or 20 deg C. I could be wrong on this and it is 10k att 0 deg C. Anyway as the temperature rises the resistance will go down. (if my memory is not failing on this point, long time since I played with thermisters.) Anyway if you put a 10k resistor between that signal and ground that will eliminate that as a problem.

Have you determined whether the problem might be that the motor is trying to run in reverse when you think it should be running forward? I really think that may be the solution. I believe you said it runs full speed in reversed the way you have it setup now.
Sep 27, 2016, 10:13 PM
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That is a good point. It has to run a certain way in order for his Dolly to track correctly but if we reverse the direction through the ESC we could reverse two wires at the motor and it would be an easy test.
I have 10K resistors here at work so no problem on that test. Thank you Mike very much, very very much for your assistance as you've given many other ideas for us.

Sep 27, 2016, 11:35 PM
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If you want to use the sensors in the motor you have to set the rotation using parameter 6 to change rotation. The sensors are related to the phases and both must stay connected in the correct order.
Oct 03, 2016, 02:40 PM
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THAT may be why I keep saying it is "cogging". It is not smooth at all. I will try this first next time we are working on it. It may be on the back burner as sailplane season is pretty much over out here now.


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