Brushless motor getting hot - in 30 seconds

[jcb]

After racing in the damp at the weekend I appear to have a problem with my Nosram brushless motor.

While racing it became intermitant with power delivery more like an on off swtich rather than stuttering, tonight I tried it again and have the same problem so I changed the sensor cable and that has not cured the problem. The other thing I noticed is that it gets noticeably warm within 30 seconds of use, say around the same temperature as it was coming off from racing after 5 minutes. The can did also seem to get warm quicker on one side of the can!!

I have not tried another motor with my speed controller and after taking my nosram one apart nothing seems obviously wrong and the rotor spins freely in the bearings.

Any ideas?

Oh and it sounds horrible to, not sure how to explain it but it doesn't sound right!!!

[bert digler]

Originally Posted by jcb

After racing in the damp at the weekend I appear to have a problem with my Nosram brushless motor.

While racing it became intermitant with power delivery more like an on off swtich rather than stuttering, tonight I tried it again and have the same problem so I changed the sensor cable and that has not cured the problem. The other thing I noticed is that it gets noticeably warm within 30 seconds of use, say around the same temperature as it was coming off from racing after 5 minutes. The can did also seem to get warm quicker on one side of the can!!

I have not tried another motor with my speed controller and after taking my nosram one apart nothing seems obviously wrong and the rotor spins freely in the bearings.

Any ideas?

Oh and it sounds horrible to, not sure how to explain it but it doesn't sound right!!!

windings in the can knackered has the solder tab broken down on one of the poles

[_sleigh_]

Have you fully dried out the motor, both under the plastic end cap and inside? It ski ds like a sensor problem (hence the noise and intermitent running)

Even a small amount of damn/condensation can stop the motor functioning perfectly.

Good test of the sensor is to try to run the motor from a stand still at every point the rotor sit naturally (if you know want I mean).

[jcb]

All the solder posts are fine and the windings inside look ok to me.

The motor should be dry, it's been out of the car since I got home from racing yesterday and has just sat near a radiator. Think I know what you mean about the rotor, will give it a go tomorrow evening.


Thanks for the replies

[DCM]

I agree with Phil, the damp has gotton into the motor and affected the hall sensor, affecting the timing pickup of the motor, so the motor is being timing advanced way to far, hence the heat, and noise. Check the bearings, spray moisture repellant into the motor, allow it to dry off, lube up, ensure the motor is ZERO timed on the end bell, and try again.

[Fabs]

As far as I know getting the sensors wet or damp is terminal for them, you might need a new sensor board on your motor, and subsequently have to send it back to mirage.

[MattW]

Getting the sensors wet is indeed a problem - for the speedo as well, as remember it is the speedo that supplies voltage to the motor sensors to allow them to do their thing. You will need to try a different motor at some point to try and narrow it down.

[KevLee]

If you hook it up to a Tekin RS it you can check that all the sensors are operating correctly..... If you are at worksop this weekend and haven't solved it by then we can have a look?

What a clever box of tricks!

[jcb]

Thanks for all the help, but still none the wiser

I have tried everything that has been suggested and the motor still gets hot and sounds sick.

I also got round to trying a different motor this evening and although it sounds normal it didn't seem to have a great deal of power, which I assume could mean that something is up with the speed controller

I would assume that by trying the motor I ran that got wet with a speed controller I know that works will not cause any problems? As that will help to narrow it down as to whether both or just the ESC is not quite running properly!!


Thanks for the offer Kev but I won't be at Worksop at the weekend.