EM 5.7 Retrofitted with Modern siliXcon SX Controller

[konrad]

The write-ups are quite technical, but maybe some here will be interested.

This link is the actual retrofit process: https://www.electricmotiontech.com/home/em-5-7/sx-controller-retrofit

This link describes some preliminary work to familiarize myself with the SX controller: https://www.electricmotiontech.com/home/em-5-7/sx-controller-experiments

[ChrisCH]

Great stuff and very interesting.  Above my pay grade on the electronics. How I wish we lived near to oneanother.

The regen on the throttle is very interesting - that would be a game changer for a lot of people that I can think of.  I agree on your observation about the clutch as well - it is a weak point on the newer bikes I think - our Factor-e is not outstanding in the clutch operation.  I would turn off the tickover for myself but the wife likes it.

We had booked to ride with Gael who was one of the development riders but his recent injuries stopped him from being able to do the training.  Hopefully that opportunity will come up again.  I would love to go through some of this with him (it will help improve my French as well......)

[nostroke]

I'm curious about some of the programming used on these bikes. I just got a 2024 pure sport with diaphragm clutch and the 3 mode settings. But I'm used to a bike I built and posted here years ago that uses a Perm brushed motor and an Alltrax 48V 400 amp controller. I am comparing the EM throttle response and general feel to my old 'Digit' I built. The Digit, because its a brushed motor, is by nature always in speed mode, so throttle command is proportional to the motor rpm as opposed to most brushless motors that typically (the EM) operate in torque mode where the throttle command is proportional to the current.

My Digit does not have a clutch but throttle response is very crisp and both splats and wheelies are very predictable and easy to control. The EM however feels really mushy response-wise and its harder for me to control since I'm used to speed mode modulation. Has anyone programmed an EM to operate in speed mode?

I also build street and road race electric bikes and have done so for many years (I'm old). On street bikes, torque mode is more intuitive but for off road use and on my EM, I think that speed mode would be better. Anyone know what I'm babbling about?

 

[konrad]

All of EM's siliXcon controllers are password locked, so only torque mode is possible. 

Back when we first got the 5.7, I experimented with the Kelly controller's "balanced mode" (somehow incorporates both torque and speed modes).  I found it most unintuitive compared with ICE trials bikes, so I did not bother to try speed mode.  See: https://www.electricmotiontech.com/home/em-5-7/5-7-controller 

Edited 10 hours ago by konrad

[nostroke]

Just curious if this is possible, within reason. I have an old relationship with Phillipe at EM from 2 decades ago and am trying to rekindle that relationship for both humanitarian and access reasons.

[konrad]

17 minutes ago, nostroke said:

Just curious if this is possible, within reason. 

Maybe, maybe not.  EM uses custom siliXcon firmware, and the speed loop routine may have been removed to make space for other code.

https://docs.silixcon.com/docs/fw/modules/esc/driver/command/driver_pid_modes

 

[nostroke]

Is it likely that the controller is available direct from siliXcon unprogrammed? Also, I should add that the Perm/ Alltrax package I used, while pretty crude by today's standards, does not use a feedback device although  a brushless could emulate that with its feed back loop I suppose. I'm not a EE but have dabbled with EV controls forever.

Edited 7 hours ago by nostroke

[konrad]

Yes.  Generic controllers are available, but lack some of EM's features.  https://www.electricmotiontech.com/home/em-5-7/sx-controller-experiments

 

[nostroke]

Oh, OK just read your link, thanks. Looks do-able but there are probably a lot of parameters that I would need from motor mfgr.

Due to the lack of any serious ramp programming on this Alltrax  golf cart controller I used here, I made an audio taper (log) potbox so you have great slow precision on an otherwise sketchy throttle and you get the big splat energy when you wick it open. Almost as good as a clutch overall but way easier to ride IMHO for medium skill level riders (me). Speed  (voltage) mode does not have that time lag that a torque (current) mode has so response is instant.

And I 'll certainly dig deeper into your experiments. Thanks for all that 

.

Edited 7 hours ago by nostroke