A full collection of electrically motorised skates, longboards, a penny and a couple of lifehacks for them (yet literally). Some just represent ideas and some are like really detailed with theory and every single processing step. You will find tips on components pick, prices, processing technics and features, installation ideas and more. All in all, with this bunch of knowledge and experience (and some money;P) you will definitely build a working one!
Out of these instr'es I can say a starter project would cost 150-400$ depending on quality and specs. And one thing that is I wanna point out: a motor should be somewhere around 90-300 KV and the rule is when you increase KV you loose torque.
This is it, enjoy!PS. If you wanna dive in, check out www.electric-skateboards.builders Gorgeous builds, pro tech and innovations.