I found this part the most difficult. Basically you need to attach a plate to the truck axel.
There are a couple of options:
- Cut a plate and weld it to the axel. This is the most common way of attaching the motor. Welding aluminium can be a little difficult I’m told but doable.
- Clamp it to the trucks: This only really works on square style trucks (e.g. calibre) and you’ll need access to a CNC machine.