Looking for a ~350w controller

[badboy1999]

Someone gave me a ebike with pretty much all the electronics missing. The direct-drive rear motor (with hall sensors) is still there, and there's a torque sensor near the rear dropouts giving an analog signal.

I'm looking for a controller to use here to bring it back to life! As I live in the Netherlands where there's a big crackdown by the police on e-fatbikes, it needs to be limited to 25 km/h, power ~250-350w, and only provide that assist when pedalling. It'd be nice to have regen braking, sine wave motor control, and a display but those are kind of optional.

The options seem to be, if I want to use the torque sensor:

• VESC with another uC to control it (or custom VESC firmware, which would be a lot of work as I never use C/C++), Flipsky sells one for 80 euro, but people complain about the build quality: https://endless-sphere.com/sphere/threads/flipsky-new-20s-100a-tiny-controller-vesc-based.113445/page-24
• Phaserunner from Grin, probably >$400 with all the harnesses and a display
• A Lishui controller with the firmware that Hochsitzcola is developing over on pedelecforum.de. Kind of expensive, on Aliexpress these controllers go for >$100 dollars, and I'd like to have an international community behind the controller, not just one german forum. Advantages: works sensorless as well
• A Kunteng controller, with an lcd-3 they go for $50-70 it seems, with the opensource firmware from Stancecoke's github. Seems very mature, but the repository isn't very lively
• A generic BLDC control board - you can find ones that support hall sensors, 6-60v, 350w (not clear how much current, might be at 60v so quite low power at ~36v) combined with an arduino that does the speed limiting and reading of the torque sensor

A Kunteng-controller seems like a good fit, I think I can just use the GUI to configure it do all I want. But Stancecoke advises against using KT-controllers in this day and age:

BTW: The Kunteng hardware ist completely outdated and the open source project is not maintained any longer.
Source: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW)

What am I to do?

 

[neptronix]

I have zero experience with kunteng controllers, other than to say for this power range, it's probably the best choice.

I've become a huge VESC fanboy though and would buy anything other than flipsky, lol. spintend is my go to; good place on the price to quality axis.

There's a couple different solutions documented for the VESC to allow torque sensing on this forum.. might want to try the google search option to unearth them.

 

[Chalo]

There is no reason at all to avoid KT controllers. What kind of busybody fool messes with a working speed controller's firmware anyway? I have more important things to squander my time on.

Honestly the KTs that impress me the most are the little tiny 15A ones that would fit neatly in a shirt pocket. I've used 22A, 40A, and 60A versions though, and they all interface the same way with a given display.

 

[E-HP]

Phaserunner from Grin, probably >$400 with all the harnesses and a display

What am I to do?

Is it a TMM4 torque sensor? I saw a thread where Justin mentions the settings to use with it and the phaserunner. Seems like the least hassle.

 

[badboy1999]

Thanks for the advice! I came across a Lishui controller integrated in a Hailong battery holder, that'd make for a really clean installation, I just ordered it for €55.

The cheaper spintend VESC controllers look good, only $89 for the no-bluetooth version, but I'd have to make a case as well, do some custom firmware, looks solid otherwise.

Good to hear KTs work well, I decided against them because with the custom firmware (that I need for compliance with EU laws) only some displays work and the github repo is stale.

The torque sensor - it says '1024-a', and one of the wires goes from 1.4 to 1.65 volts when I put some force on the pedals, that's all I know. It has a lot more wires than the TMM4 sensor I can find with google.

When the build is finished in a few weeks I'll make a post!

 

[badboy1999]

Update, I managed to find the original owner of the bike, it's unclear what happens now, for the time being the project is abandoned. I did learn a few things about the Lishui controller, see my reply here: Lishui "Open Source Firmware" project / KingMeter 5S

 

[Chalo]

You're much better off with a real bike anyway. E-fatbikes (especially small wheeled ones) only advertise loudly that you don't know what you're doing.

 

[slaphappygamer]

KT controllers are great. Here is the manual for the LCD8H, but the (cheaper) LCD3 and other LCD displays have similar settings. Have a look through the manual. You’ll see that you can limit speed and power without custom firmware. Good documentation is another reason why KT controllers, and displays, are highly recommended. Here is the kit I bought. It worked fine for about 2 years. Then I upgraded to a CycleAnalyst/BaseRunner setup.