There's a full video blog of this here.

The TrakTrike is driven by 2 x 2kW BDLC motors, one for each track. I planned to control speed with a handlebar twist grip. To enable me to trim the speed of each motor I decided to use an Arduino Nano to sample the throttle position , and then split this off to set the value of two digital potentiometers. Using this method I can adjust the speed value to each side individually. For motor controllers I'm using the stock devices supplied with the motor itself.

I'm also adding a LCD display and a rotary encoder/switch combo to allow me to navigate through various functions.

I designed a schematic using Design Spark PCB.

Then I designed a PCB. It's pseudo doble sided. I plan to CNC route it, so I minimise top layer tracks and simply connect them with tinned copper wire. I also have to ensure that any connectors are only routed on the bottom layer as there is no way to solder the top side with the connector in place.

I then CNC routed the PCB

And built it up.

The digital pots I'm using emulate the potential divider of the twist throttle. Frustratingly I discovered  they default to half way when powered up so I replaced them with an equivalent part that stores a power up value in EEPROM. I had to create a small programming circuit to allow me to reset this value to zero.

To house the electronics and other wiring, I used an off the shelf IP66 project box. Besides the LCD and control, I'm adding two battery status displays and a battery cut off switch. I designed the front panel layout is Fusion360.

I thought it would be nice to theme the panel with an indented logo. 

Once cut out, I used squeegeed black acrylic paint into the letters and cleaned excess paint up with a sodium bicarbonate paste after it had dried.

After wiring everything together it was time for a test.....and a couple of things became apparent.

1. Starting torque seemed to be a problem.

2, Stability. In a previous log I mentioned that the track width seemed to be a little narrow. This was confirmed when my son managed to tip the TrakTrike.

At this stage, it's about 6 weeks to EMF camp 2024 and I need to move fast.

There's a full video blog on the electronics and initial testing here: