motor "chattering" problem , help
 

hey everyone,

got a slash 4x4 lcg , burnt up my vel motor at track and shop owner sold me a sensored smc 8.5t brushless. I soldered the joints and hooked it up (14t pinion , 52t spur).....but it wont get going.....it putts around and chatters and shakes , i tried adjusting the timing dial on end of motor every which way but does nothing....it came with sensor wire but my vxl-3s has no port

are these compatible ???

any help would be appreciated

thx,
Jon

Driving a sensored motor with a non-sensored ESC? I don't think that is going to work. I think you can run a non-sensored motor with a sensored ESC, but not the other way around. Somebody correct me if i'm wrong.


-Cpt.

I've done it, with a sensored Turnigy Trackstar and HW esc, worked fine. I did discuss it with someone here beforehand and they said the motor just defaults back to -0- timing without the esc timing input. I would say there is something wrong with that esc. I also have a LRP 17.5 sensored motor here that runs fine on a Mamba Max esc without sensor. I would guess the esc mosfets are damaged. They are the "timing" of the esc. They switch the fields in the motor windings to start the motor and keep it running.

i just dropped in a new traxxas vel motor and it rips around like normal.....so it cant be the esc.......with the sensored smc 8.5t.....if you lift the truck off the ground and throttle , the wheels spin just fine , ballon out at high rpm etc.....its just when you put it on the ground its starts chattering , im wondering if the low turn of the motor , and the higher torque needed for the 4x4 are the cause...........its does not like this motor for what ever reason.............maybe the motor is higher that 3500kv , thats the limit of the vxl-3s esc...........motor or packaging does not spec out kv

IIRC the vxl esc cannot operate sensored set ups . Not all esc's have a dual mode , a lot of them do , but im thinking the vxl does not.

so , you are saying that you cant run a sen motor with a non-sen esc.....???

the "pro" who sold it to me at the track , said you can do either

well i guess i will just throw it into the parts bin for a later day (when i upgrade the esc)

thx

Not all sensored motors can run on a sensorless speed control. None of the sensored motors that I have will run on a sensorless speed control. They all do exactly what his is doing.

I agree, sounds like the motor you got wasn't designed to be run without the sensor hooked up. The slowness and cogging you're getting is a classic sign of a sensor issues. If you put a good motor on it and know it's not the speed control then the only other logical conclusion is the motor. My guess is the motor requires a sensored speed control.

Look up the specs on the VXL and see what it says.

Other way around. A sensorless esc doesn't care what motor.

Turn the can timing back to 0 and see if it helps at all

Read the specs. Says sensorless motor compatibility.

http://www3.towerhobbies.com/cgi-bin...&I=LXEJSG&P=ML

Auto detects brushed, brushless or sensored brushless motor types
Compatible with 4-cell NiCd or NiMH batteries up to 3S LiPo packs

Sensor phase detection protects against improperly wiring aftermarket
sensored motors


Sensored motor backup protection switches to sensorless operation if
motor sensor fails

SPECIFICATIONS

Input Voltage 4.8 - 11.1V (4-9 NiMH, 2S-3S LiPo)
Motor Compatibility: Sensorless Brushless
Motor Limit: None

Seems to say a lot of things ...

The motor is sensored, and therefore it probably won't work properly with a sensoreless speed control. Everyone keeps saying things about the speed control Yes, it will operate a sensored or sensorless speed control but it doesn't say anything about a sensored motor working with it. All of his issues he's described are classic sensor issues. More than likely the motor that he got won't work without having the sensor wire hooked up properly, which is impossible on a sensorless speed control. Just because the speed control will work with any sensored or sensorless motor doesn't mean the motor will work with any sensor or sensorless speed control.

My old vxl esc's have sensor ports.
Click the link in one of the above posts and look at the pic...that little blue rectangle surrounded by black border should be the sensor port.
Pull the plug. Hook up a sensor cable from there to the motor and give it a shot again.

Yep...looks like the port has a plug in it. Didn't notice that before.