This is a concept electric skateboard made in Fusion 360. You can go and build this skateboard right now by using the blueprints provided.

Step 1: The Parts:-

I am not an expert in skateboards so if you are going to be building the Skateboard you will have to do some research on the topic. First, you will have to decide if you want to build the board by scratch or buy one. If you want to build one then you will need:-

Maple wood
80mm wheels
a suitable trunk

There are cad files and blueprints attached to the instructable which has only the longboard construction.

To make the board electric, I suggest you do your own research first. but basically, you will need:-

a BLDC Motor 6374 190kv (170kv -200kv should be fine)
a VESC that is rated for 50A.
remote control for the VESC
2 gears with a suitable belt (in the design I have used 20 teeth and a 60 teeth gear)
batteries that your ESC can handle (i will use 2x 6s lipo batteries in series to provide an effective 12s battery

If you are not sure on what specs you have to use then check this site. It will help you make better decisions.

Step 2: Building the Enclosure:-

You will need to make an enclosure to cover the electronics. Make the enclosure just big enough to fit all your components, don’t make it too thick as you will need some ground clearance. You can use an old plastic box or custom fabricate a metal enclosure. Drill a hole on the end of the enclosure for the motor wires, also add a switch and an easy port to charge the batteries.

Step 3: The Motor Assembly:-

First, take the bigger gear and then you will need to make the hole in the middle big enough so that it can fit through the trunk. Then you will need to drill holes to mount the gear to the wheel. You will also have to drill holes through the wheel that match with the holes drilled on the gear. Fasten the gear to the motor using bolts(add nuts if necessary).

Next, you will need to attach the motor mount to the trunk, ensure that the mount is secure and will not slip and rotate. Then use bolts to fasten the motor to the motor mount, I recommend also fixing the motor to the board to ensure that it won't move out of place. Mount the smaller gear to the motor.

Add the belt and then fix the wheel with the gear. Ensure that everything moves freely.

Step 4: The Wiring:-

Connect the motor wires to the ESC, if you are using two batteries then connect them in parrel or series depending on your configuration before connecting them to the ESC. After this, you should be ready to ride it.