Direct Drive hub won't turn, what have I done wrong?

Hi All,

This forum got us pretty far in our first electric bike build, but it seems we may have hit a hurdle. I've tried to look for a similar problem and couldn't find anything, unless the search terms I used weren't correct.

The battery we're using is a 21S 18650 pack running a Cromotor V3, an 18fet infineon based controller with a CAv3DP. Current is set to 60A on the controller and 60A on the CAv3. R shunt is 1.232ohms

Tried different phase combinations, and about to try different hall sensor combinations, although all the wire colours matched up as per this post http://endless-sphere.com/forums/viewtopic.php?f=2&t=48099

Need to test the voltage off the throttle plugged into the CA, but it does register on the display. The other thing is once the CA is reset and turned on, regen just continues to climb till it hits 999.99%. There are some images below.

The motor doesn't freewheel smoothly, and on every rotation I manually pedal when it's off the ground, the CA display brightness flickers. Not sure what's going on here and any help is appreciated.







No throttle applied


Max throttle applied

I haven't tested it with the CA outside the loop. Will need to create a quick 4 pin tail that goes into the controller throttle since the CA uses the standard 3 pin plug.

Yep I've been going through that user guide when i was wiring everything up and setting up the CA through the software utility.

The motor spins fine with zero resistance when the phase wires aren't plugged in and I'm just pedalling it in the lowest gear. Nothing rubs and everything seems in order so it's not mechanical.

I'll start by removing the CA and go from there.

Didn't get very far. But at least I know now what was originally causing the issue. A short in the controller!

Finished wiring up the a new plug on the throttle for the controller.

Plugged the battery in and bang. Breaker went off (I've got the ++ on the battery end, as these breakers fry if reversed in DC). Checked the polarity, everything looked to be in order, and nothing was changed anywhere else apart from the throttle plug. Controller is set to 60A/150A phase, and the breaker is rated to 63A and 150VDC.

Opened the controller, magic smoke, and a blown fet. How would've this happened? Can't see any visible shorts.

Checked the phases on the motor, spins freely with no phases connected, and a good amount of resistance when each phase is shorted (this means the motor is ok right?) I'm guessing the short was at the controller since i remember a good amount of resistance once it was plugged in with no power.

Hoping nothings wrong with the pack.

Just checked the controller and it looks like when I connect the blue phase wire, I get the resistance when trying to freewheel it. Wish I had done this before I blew the fet to know if it was a short on the blue phase beforehand.

Presumably when the Cromotor is plugged into the controller with the correct phase and hall sensor combinations, the motor should easily free wheel as it did when i had no controller connected which would indicate no short?

Yes, you nailed it. Resistance when you plug in the controller to the phases indicates a short in the controller.

A good functioning controller will not increase the resistance when you turn the wheel, once you plug in.

Touch two unplugged phase wires while it's not connected to the controller, and you will see. A short will increase cogging a LOT! So that cogging when you plugged in means it had a short.

Unplugging the controller and deliberately shorting the phases to the motor is a great way to "lock" your bike.

Thanks for the clarification. Makes sense now when people talk about wheel locks and phases.