The motor mount
I found this part the most difficult. Basically you need to attach a plate to the truck axle. Simples right?
Kit (which is clamp)
Welding the motor mount
Cut an aluminium plate and weld it to the axle. This is the most common way of attaching the motor. Welding aluminium can be a little difficult I’m told but doable. I’m told you can take it to a local Tig welder to get this done. I called around a few places in Oz and someone said they would give it a go for $50 (no guarantees)
Doing this you will need to create a plate out of aluminium. Why aluminium skateboards trucks are cast aluminium. You’ll need to include some type of sliding mount holes for the motor as you’ll want to maintain tension on the belt. More on the belt and calculating the distance of the belt from the size of the cogs, belt length etc in the motor en pulley section.
Clamping the motor mount
Clamp it to the trucks: This works best on square style trucks (e.g. calibre or the like). However, you’ll need to fashion a clamping mechanism to attach. Your can hand cut a plate from basic hand tools and use a thread tap for the screws. Or if you have access to a CNC machine and some cad skills, it makes it much quicker/precise.
Motor mount kits
Buying a mounting kit. They all clamp these days. Check out my link of options here.