Swytch Mk3 Air problem with third-party hub

[jahknob]

I have a Swytch Air (mk3) set up with the LCD controller connected to a XieTong Q100C CST 36V 350W rear hub motor. This is my second “hybrid” set up for a Mezzo folding bike and the first one (similar hub, think it’s an Q128?) works with no problems.
This new build is showing some strange issues. I’d be hugely grateful if anyone on this forum can give me a steer as to what to do/try.
When everything is connected up and I use the throttle to just test that the motor gets power and runs in the right direction, it works, but the throttle doesn’t seem to ramp up power smoothly (I get the impression it’s pretty much all or nothing - but that could be me looking at the wheel spinning and not being able to tell), and the controller goes straight from indicating 0 to 99km/h (settings are for 16” wheel with 25km/h maximum).
Even odder is that when I connect up the pedal sensor, I can get it to flash once or twice, the motor starts, but then immediately stops and the pedal sensor stops working - but the controller shows 99km/h (even though nothing is turning/sensing) until I switch controller off and on again - then I can get same thing to happen again - flash once or twice as I run magnets past it, motor just about kicks in, then all goes dead again.
And the throttle won’t work at all with the “dead” PAS connected either.
(Full disclosure - the hub has been taken apart and all wiring disconnected to allow for a modified stub axle to be fitted, then all very carefully reconnected by an electronics whiz pal of mine)
At some point I will swap the two rear wheels between the Mezzo bikes to see what happens, but I am guessing that it’s maybe a settings issue?
I am NOT any kind of an expert - think I’ve just been lucky to date pairing non-Swytch motor wheels to Swytch set-ups in the past..
Thanks in advance to anyone who might be able to help!

 

[saneagle]

I have a Swytch Air (mk3) set up with the LCD controller connected to a XieTong Q100C CST 36V 350W rear hub motor. This is my second “hybrid” set up for a Mezzo folding bike and the first one (similar hub, think it’s an Q128?) works with no problems.
This new build is showing some strange issues. I’d be hugely grateful if anyone on this forum can give me a steer as to what to do/try.
When everything is connected up and I use the throttle to just test that the motor gets power and runs in the right direction, it works, but the throttle doesn’t seem to ramp up power smoothly (I get the impression it’s pretty much all or nothing - but that could be me looking at the wheel spinning and not being able to tell), and the controller goes straight from indicating 0 to 99km/h (settings are for 16” wheel with 25km/h maximum).
Even odder is that when I connect up the pedal sensor, I can get it to flash once or twice, the motor starts, but then immediately stops and the pedal sensor stops working - but the controller shows 99km/h (even though nothing is turning/sensing) until I switch controller off and on again - then I can get same thing to happen again - flash once or twice as I run magnets past it, motor just about kicks in, then all goes dead again.
And the throttle won’t work at all with the “dead” PAS connected either.
(Full disclosure - the hub has been taken apart and all wiring disconnected to allow for a modified stub axle to be fitted, then all very carefully reconnected by an electronics whiz pal of mine)
At some point I will swap the two rear wheels between the Mezzo bikes to see what happens, but I am guessing that it’s maybe a settings issue?
I am NOT any kind of an expert - think I’ve just been lucky to date pairing non-Swytch motor wheels to Swytch set-ups in the past..
Thanks in advance to anyone who might be able to help!

You have the wrong speed sensor settings in your LCD. Which controller and LCD are you using?

 

[jahknob]

I guess I didn’t make it absolutely clear that it’s the Swytch top-of-the-line LCD controller/display, but I have no idea how to go about accessing any settings other than the standard options of wheel size and max speed, that Swytch give instructions for - and I have already done those settings - 16” and 25km/h

 

[saneagle]

I guess I didn’t make it absolutely clear that it’s the Swytch top-of-the-line LCD controller/display, but I have no idea how to go about accessing any settings other than the standard options of wheel size and max speed, that Swytch give instructions for - and I have already done those settings - 16” and 25km/h

You changed the motor. How would anyone know whether you changed the controller or not unless you tell us. You'd be surprised at how many times we've tried to help people on this forum when they missed vital information that would send the solution in a completely different direction.

Have a look to see if there are any numbers on the back of the LCD. The problem with that type is that there are many different ones that all share the same case, like SW102, DM03, KT LCD4 and more, and each version has different software versions too.

 

[jahknob]

Thanks again for the response. It’s a Topology SW102 controller. If there’s any other info that you think might help get to the bottom of this issue, please just ask..

 

[saneagle]

Thanks again for the response. It’s a Topology SW102 controller. If there’s any other info that you think might help get to the bottom of this issue, please just ask..

AFAIK, the SW02 doesn't give access to the setting. Here's the manual for everything else:

https://ride1up.com/wp-content/uploads/2021/01/Roadster-V2-Display-Manual.pdf

Your speed is being calculated many times to fast. Let's say that the original motor had a single magnet in it to get te correct speed. Logically, the controller is getting too many pulses. If a controller cannot get the speed signal from the speed sensor, they often default to getting it from the hall sensors., which would give many pulses per rotation, so that's probably what's happening.

First question: Does your new motor actually have a speed sensor in it? If it doesn't, you should be able to solve your problem by using an external wheel magnet one. Whatever, you should test the speed sensor signal to see what's going on. It's on the white wire in the motor cable, which is also where you need to connect an external sensor. If your system doesn't allow you access to the white wire, you either need to do some hacking or you can take the controller out of its aluminium case to get accesss to where the white wire is soldered. You can also make a test lead using a female 9-pin motor connector.

All said, it might be an idea to swap the controller and LCDs for ones that does what you want. The KT controller is better anyway. It gives better pedal assist function and allows you to use a throttle or push-button as an instant max power override.

 

[matthewslack]

It sounds like there is nothing wrong except the lack of the speed sensor signal.

If the controller thinks it has a 99km/h speed signal, it should shut off power because it is enforcing 25km/h, so working as designed.

Fix the speed sensing issue and likely the rest will be sorted.

Your mix and match is opposite to most Swytch issues, where just the motor survives and everything else is replaced!