ebike kit for art project pedal assist not working

[jp855]

Testing my Amazon ebike kit with this motor on the bench and I cannot get pedal assist to activate the motor. The throttle works fine but pedaling does nothing.

This is for an art project where a user pedals a stationary crankset with no chain or rear wheel. The pedals spin a PAS sensor that is supposed to activate the ebike motor, which then spins a separate "art wheel."

I have tried multiple controllers, motors, PAS sensors, and displays. I have checked wiring and connectors, adjusted PAS alignment and magnet direction, and gone through the PAS settings on the displays. No matter what I try, throttle works but PAS never triggers the motor.

So my questions are:

Do some controllers require the motor or wheel to already be spinning before PAS will engage?

Is there something inherent about a stationary bench setup that would prevent PAS from working?

Is PAS the wrong approach for this application, and is there a smarter way to trigger the motor from pedaling?

I feel like I am missing something fundamental. Any insight would be appreciated.

 

[RunForTheHills]

Some controllers require a full 360 degree rotation of the crankset to activate. I don't think the hub motor needs to be moving, but that is possible. There are hall sensors in the hub motor also. It is more expensive, but you could look at getting a Cycle Analyst v3 from Grin to connect the PAS sensor to. It would then send a throttle signal to the controller.

Cycle Analyst V3 - Grin Products - Our Products

 

[Apartunis]

Do you have the sensor flipped around? The plastic block with Hall effect sensors in it must face the magnet ring.

 

[E-HP]

adjusted PAS alignment and magnet direction, and gone through the PAS settings on the displays. No matter what I try, throttle works but PAS never triggers the motor.

Please first confirm that you did not randomly plug in components, other than those supplied with the kit, into this kit's components, hopefully not. Doing so introduces the possibility that you've damaged the kit components, adding another layer to troubleshooting (testing the the kit controller wasn't fried, etc.).

When mounted on a bicycle, the two piece PAS sensor like yours must be oriented correctly. The side of the crank that it is installed matters (drive/right side, left side), orientation of the disc (usually there are small arrows for rotation on the disc, that should face outwards from the crank when mounted), orientation of the sensor, distance and alignment of the sensor to the magnets). For many, there may also be parameters in the display that need to be set, although I don't believe that is the case for the DC Moto/JN controllers like in your kit.
PS. If you're just spinning a wheel on a table, and not using the motor to power a bike, etc., then the controller you purchased is kind of overkill, since unloaded, the motor will only consume 50 watts or so, a couple of amps at most.

 

[yooper2001]

Did you measure the 3 pas wires with power hooked up? Power to ground and gound to signal? Power to ground should be over 4. ..signal to ground should pulse less voltage on/off. If the sensor works, you have remembered to set up the PAS magnet setting in the display? I remember I forgot this, and after 6 hours of frustration, I remembered, set my PAS magnet setting..and it worked.

 

[AussieRider]

G'day jp855
D'you know that id you connect two brushed PM motors by the wires, spinning one spins the other? Seems a much simpler solution to me. No controller, no batteries, just two motors & a bit of wire.

AussieRider

 

[fill]

The troubleshooting guides over at ebikes.ca detail a pas sensor test iirc in easy to follow steps.
you generally need to both turn on the ebike system and then select a non zero level of assistance via the controller to start/enable the assistance.

there can be a noticeable delay between starting to rotate a pas sensor and the resulting activation of the motor which can differ between controllers some have a more immediate start/stop than others, but all will require a minimum turn to generate the recognisable pattern of pulses expected.

Just thinking aloud as its not for a road vehicle.. Whats the deadline? you have a throttle control you can use to set the required speed? pas cadence control is usually full power to x rpm the higher the pas level the higher x rpm (speed)...

Kits usually come with brake cut off sensors too.. so you could use the pedalling to turn on/off a brake cut off sensor while setting the speed of the motor with the throttle ( rubber bands can increase resistance friction for sprung throttles).

 

[jp855]

Thank you everybody for the input. This was all very helpful. I did manage to get it working. I've been messing with this for a month, and I guess today was the day it decided to start working. I think the solution was in the P settings. I swear I've tried this a dozen times already but I changed a few things in the settings and now it works. I even have solid top speed control, which will be important.

I'll report back in a couple months and share the final art piece once its installed. (gotta be a bit secretive at the moment)