CA3-BBS-FOC Project

[Jackass]

Part one: Prologue

Grin’s CA3 is a great product. Same goes for Bafang’s BBSHD. Because I don’t like clutter and double displays, I bought a CA3-BBS conversion set from Reinhard at e-bike-technologies.
Almost perfect. Almost because the CA3 expects a ‘dumb’ controller and the BBSHD is half-smart/half-dumb.

In other words, the CA3 and BBS controller should work as a team, but when it comes to such things like pedal assist or gear sensor, they don’t seem to agree.

I tried to solve this - special thanks to Teklektik - by rewiring the innards of the BBS controller but damaged one beyond repair. Lucky for me Reinhard came to the rescue. He had a FOC controller laying around for testing purposes. This controller was made by a German wizard called Bartek (http://www.barmal.de) and has several improvements over standard ebike controllers: it behaves like a sinusoidal controller at low speeds and a trapezoidal controller at high speeds. Even more important, I don’t expect the CA3 and the FOC controller to ‘fight’ over who does what and why.

As I’m writing this post, Reinhard is wiring the FOC controller and Bartek will be connecting the phases and hall sensors.

Next step is I hook up the CA3 to the FOC controller and BBSHD and let everybody here at ES enjoy the perfect ménage à trois between CA3, BBS and FOC. Or not

 

[electricwheels.de]

part 2 - the Bafang BBSHD motor


greetings.

Here the prepared BBSHD motor:


The temperature sensor is directly fixed to the stator windings. You can see the 2 thin blue wires sticking out at the top.


Once the motor is mounted to the case, the cable entry points are sealed with silicon adhesive sealant:


The hall sensor wires are terminated with a male 6-pole JST connector, the temperature sensor wires with a male 2-pole JST connector.


The wiring harness is custom made:


On the left side you can see the 3 phase wires terminated with a MT60 male connector. The hall sensor terminates in a 5-pole male HIGO connector.
In the centre you see the male 6-pole HIGO connector for PAS, DIR and NTC signals.



On the right you see the 4-pole female JST connector for PAS and DIR, the 2- pole female JST connector for NTC and the 3 phase wires, here without connectors.


And here the assembled BBSHD drive unit, ready to mount:


The 6-pole Higo cable will be lengthened to suit after the drive unit has been fitted to the bike.
The motor cable can be shortened if required.

next: building a water- and dustproof IP66 rated controller

cheers for now
Reinhard

 

[electricwheels.de]

part 2 - preassembling the controller board

Here the original board:

View attachment 8
dimensions are 120 x 80 x 28 mm, or about 5" x 3" x 1 1/8"


The front panel, already drilled:


glands and HIGO panelmount connectors in the front, gasket in the background


Front panel with hardware mounted:


The phase cable, terminated with a MT60 connector, is inserted.


The front panel from the rear:


No space to waste...


First the phase wires are terminated with connectors and mounted:

View attachment 4
allow a loop so that the board depth in the case can be varied somewhat.
Notice that the capacitors were secured with white silicon adhesive so they don't shake themselves off the board under vibration.


The battery cable is mounted:

View attachment 3
The shunt is crimped into the negative wire. S+ and S- wires are attached, the subassembly enclosed with heat shrink tubing.
Note the red securing laquer on the terminal nuts/threads.


The 8-pole female HIGO-B8 main cable is mounted and all signal wires are connected and bundled:

View attachment 2
Isolation compound is applied to the soldered terminals of the board connectors.
Some Kapton tape is applied to the capacitors as an added isolation layer between capacitor and controller case.


The subassembled board and front plate are now ready for insertion into the controller housing:



that's it for the weekend. Time to grab my e-bike and head into the sunset...
Cheers
Reinhard


next - completing the controller

.

 

[electricwheels.de]

.
part 3 - assembled controller

finally got the controller assembled:



View attachment 1

# controller dimensions 160 x 106 x 32 mm or 5 1/2" x 4" x 1 1/4"
# IP rating is IP66
# battery and motor cable from GRIN technologies
# XT90-S battery and MT60 phase wire connectors from AMASS
# Signal connectors HIGO Mini-B series

next: fitting the motor and controller to the bike

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[electricwheels.de]

.
When mounting the motor watch out when you fasten the 2 M6 socket cap screws.
The lower thread is only usable to the depth of the motor housing.
If you use a screw that is too long, it will punkture the gasket, allowing moisture to enter the motor housing:



laying the housing side by side, you can see where you end up:

View attachment 1

This is the thread to watch out for:


.

 

[justin_le]

Fascinating rework guys and nice details on the build thread, the controller packaging and wiring are all very tight.

Has the FOC controller been tuned to the motor yet and the system tried out on the ground? I'm very interested to hear how this all works out so keep the details coming!

 

[Ykick]

Subscribed....

 

[Tats]

Very interesting - Am I right in assuming this would work on BBS02 when found to work on the HD?

 

[tomjasz]

Any news from users? Some comments on ES FB.



Patrick wrote, Yes I'm using it, but I bought the DIY kit, since I sell the CA V3 in my shop. I'm still struggeling to have a linear ramp up of power and sometimes the power is going up without doing anything. I have tried many settings. I'm using also the Gearsensor and even in the lowest PAS settings the stop is longer than with the original display. But nice to have the temperature and accurate powermeter. I recommend you to buy a Potentiometer for the handle bar to adjust easier the motor power.

Could problem be in wring of changing to higo connectors, or?

Their Grin USB TTL to program cable parts is very well made.


https://www.e-bike-technologies.de/table_compare_EN.pdf