Motor hmm and stall when starting to accelerate

Hi,

My hub motor hums very strong and stalls when i accelerate from stand still.
One I start rolling, i release the throttle for a second and then it disappears and the bike accelerates and cruises ok.

Its a 250w motor.

1. I recently swapped the esc to a 350w and rephased the motor (tought it the correct direction) for the first few rides it was ok and then it started with this hum+stall.

2. I added a display (sw900) and i have an error code 007, i added the display only after the humming so i am not sure if it is related or not to the problem at hand

3.the display shows speed only when i push the throttle, i can be cruising at 30 kph, if i let the throttle go, it shows 0 kph.. I assume its probably unrelated.

Uploaded a short clip:

https://youtube.com/shorts/s6rcREhMcWA?feature=share

It sounds like the hall/phase mapping is off. You may need to try a different combination of hall/phase wire colors. The motor should start from any position and reach full speed without drawing excess current (wheel off ground). There are some topics here about matching the hall and phase wires.

If the motor is a geared hub motor, it would be normal to lose the speed reading when the motor is off, assuming it picks up the speed signal from the motor.

Thanks for the advice

If the wheel is off ground it works just fine from 0 to top speed.
The problem occurs only when i sit on the bike and try to accelerate (i know, i need a diet..)

Yes, it may go full speed with no load even when the hall combination isn't right. But if you have a way to measure the current, I bet it's a lot higher than it should be at no load. I would still try swapping some wires to see if you can get it to run properly.

Berko said:

for the first few rides it was ok and then it started with this hum+stall.

Click to expand...

If it was working, then started the behavior, then I'd recheck your hall sensor connector and wiring. If your controller supports sensorless mode, then if it detected a problem with the halls (or poor connection), it could be defaulting to sensorless, which would be noisier and not as smooth at startup, but would smooth out once it gets running.

fechter said:

Yes, it may go full speed with no load even when the hall combination isn't right. But if you have a way to measure the current, I bet it's a lot higher than it should be at no load. I would still try swapping some wires to see if you can get it to run properly.

Click to expand...

I dont have a way to measure the current

What wires should I swap if I do?
I notice that there are 3 thick ones for the current and I think three very thin ones that i assume are for the hall sensors?.

E-HP said:

Berko said:

for the first few rides it was ok and then it started with this hum+stall.

Click to expand...

If it was working, then started the behavior, then I'd recheck your hall sensor connector and wiring. If your controller supports sensorless mode, then if it detected a problem with the halls (or poor connection), it could be defaulting to sensorless, which would be noisier and not as smooth at startup, but would smooth out once it gets running.

Click to expand...

OK
Thanks
Ill check the connection

Do you think I should I rule out a gear problem? That was my first hunch.

If the motor spins freely by hand, I don't think it would be the gears.

Here's the old topic on matching hall and phase wires:
https://endless-sphere.com/forums/viewtopic.php?f=16&t=3484

For some reason, it seems every company uses a different color scheme. There does not seem to be any 'standard'. You frequently need to connect the wires so the colors do not match to make it run right.

When testing, go easy on the throttle. Wrong combinations can create abnormally high currents in the controller.