Turnigy SK3 Motor + Ezrun 150A ESC slipping problem

[MaximeB]

Hi,

I recently built an electric longboard, powered by a Turnigy SK3 192Kv motor and a Ezrun 150A ESC.
But some days ago, it stopped driving: the motor has lost all of its power. It rotates, but the axle itself is not rotating (starting when applying a very little resistance).

I really don't understand what the problem is. A friend of mine just made exactly the same board, same setup, and he has no problems.
I have driven around 50kms with the board till now. Is the motor broken? Or what could have happened? I already tried changing the settings of the ESC with no luck.

To show the problem, I made a quick video on youtube: https://youtu.be/j45lPId2l-E (motor is turning just slowly for example, but when trying to drive the longboard, the motor just spins and gives no thrust at all, so it is useless).

Thanks for your support
Maxime

 

[RogerD]

Your motor shaft is slipping inside the pulley.

There are several ways to stop this.

1) Grub screw - but it's nto enough - even on a flat surface.
2) keyway - grind the motor shaft and use a pulley with a keyway.
3) - what I did - grub screw with flattened shaft AND JB Weld glue.

Option 2 is the best way,

 

[MaximeB]

I checked and the pulley is not slipping. I have grinded two flat surfaces in the shaft, and locked the pulley with two grubscrews (using lock-tite)
The whole rotor is just not rotating (including axle), but the outer housing does keep rotating. It looks like the magnetic field is not strong enough/out of sync to rotate the rotor.
Or maybe the axle has internally loosened from the outer housing?

 

[maxchilton]

there is a set screw at the bottom of the motor that holds the shaft to the outer can. Tighten that.

 

[MaximeB]

Thank you ! That was indeed the problem! They did come loose but not completely, that's why it was still rotating when not applying resistance.