Electric Skateboard

Hi,

I love PEVs (Plug-in electric vehicles), so I decided to make one that I could use while I'm at college since I won't have a car. I wanted it to be small to not take up much space, yet powerful enough to commute and explore with. So I decided to make a 5000-8000-watt electric mountain board that can travel up to 40 miles on a single charge and comfortably reach 30 mph on any terrain!

The skateboard uses the electric motors as brakes, and they are also used to regenerate power back into the battery.

This is how I made it!

Parts

1. 1x Carbon fiber mountain board deck (for durability and flexibility)
2. 1x Fiberglass encloser (durable and lightweight)
3. 2x Electric mountain board trucks
4. 2x Flipsky Motor mounts
5. 2x 8in Font wheels
6. 2x 8in Rear wheels with pulley sprocket
7. 2x 5M Belts
8. 1x Roll of grip tape
9. 1x Roll of foam

Electronics

1. 84x Molycel 21700 lithium-ion cells
2. 1x BMS
3. 1x Charge port
4. 1x Smart charger
5. 2x Flipsky Motors
6. 1x Vesc Dual motor controller
7. 1x Voltage/percent display
8. 1x RC remote/receiver
9. Wire (4,12, and 18 AWG)
10. On Switch

Material

1. Solder
2. Nickle Sheets
3. Fish Paper
4. Silicone Glue
5. Fiberglass tape
6. Shrink wrap

Materials

1. Soldering Iron
2. Voltmeter
3. Glue gun
4. Drill
5. Flush nuts
6. Bolts
7. Washers

First, I assembled the parts to create a roller chassis so the skateboard was easy to work on. A roller chassis is the basic framework of a vehicle because it can roll, but it does not have a powertrain. This includes the deck, trucks, wheels, motor mounts, motors, and the grip tape.

1. Mount the Trucks: First, I attached the electric mountainboard trucks to the deck using the appropriate bolts and nuts.
2. Install the Motor and Mounts: Secondly, I secured the motor mounts to the rear trucks. Afterwards, I mounted the motors with the pulleys.
3. Attach the Wheels: Next, I installed the 8-inch wheels onto the trucks' axles. I then ensured the rear wheels had the pulley sprockets attached, while the front wheels did not. This also allowed me to connect the motors to the wheels using the 5M belt on both sides.
4. Apply Grip Tape: After, I carefully applied the grip tape to the top surface of the deck. This provides the necessary traction for my feet to stay connected to the board. You can also add footstraps for additional support.

After finishing my roller chassis, I began building the battery pack. This is the most critical and potentially dangerous step, so I had to really take my time.

Before I began making the battery, I measured my enclosure to determine the size of the battery I could fit while keeping the weight down as much as possible.

I found that I can fit a 12S7P battery in the enclosure, so I ordered 84 cells and started building.

1. Cell Sorting and Testing: First, I used a voltmeter to test each of the 84 Molycel 21700 cells to ensure they are at a similar voltage and in good working condition.
2. Assembly: Second, I used silicone glue and fiberglass tape to group the cells into the 12S7P configuration (12 groups of 7 cells in parallel). The silicone glue will provide a durable and flexible bond.
3. Prep: Next, I covered the cells with fish paper rings around the cells' caps to prevent shorts.
4. Spot-Welding: Then, using a spot welder, I connected the cells using the nickel sheets and left a tab to solder onto to wire them in series to form the full pack. I used copper wires to connect the groups in series so the pack could flex with the enclosure and the deck.
5. BMS Installation: After connecting and wiring the battery in series, I tested the voltage and then proceeded to wire the BMS (Battery Management System) to the battery pack, following its wiring diagram to ensure a neat setup in case of future servicing. The BMS is essential for protecting the battery from overcharging, over-discharging, and short circuits.
6. Finalize the Pack: Finally, I soldered on the battery leads/charge port and covered the battery in shrink wrap to protect it from damage and moisture.

After I finished the battery, I connected all of the electronic components and placed them inside the enclosure.

1. Install the VESC: First, I installed the VESC and added 5mm bullet pins to the dual motor controller so I can quickly attach and detach the motors in case I need to replace one in the future. Then, I connected the VESC to the battery pack using the 4 AWG wires and an XT90 connector.
2. Install the On Switch, Display, and Remote Receiver: Next, I installed the on switch, voltage/percent display on the battery, and connected an RC remote receiver to the VESC's receiver port.
3. Secure the Enclosure: Finally, after all of the wiring was complete and double-checked, I sealed the enclosure to the board by drilling holes and using the flush nuts and bolts to screw it onto the deck. I also added foam in between the enclosure and the deck to keep out water.

Before I could ride the skateboard, I downloaded the VESC app to tune the controller so it would know both the battery and motor specifications. I added safety features through the app, such as traction control, and also adjusted the strength of the brakes and acceleration. The VESC app offers numerous settings and safety features, allowing you to personalize your riding experience to your preferences!

Happy making!