Introduction: Electric Skateboard

So you want to make an electric skateboard? I'm honored that you chose to look through here for help. This is my first electric skateboard build, but I will try my best to showcase my process. The goal of this build was to create a means of transportation that can conquer the hills of campus and get me to class on time. I just think it would be nice to enter the lecture hall without sweating and panting profusely. I hope this inspires you to build your own, or even branch out to other similar projects like an electric bicycle or drones. Please ask any questions and I will answer them to the best of my ability. Now let's begin!

Supplies

  1. Longboard Deck (favored for its large mounting space, flatness, and rigidity) - [$60 - $200]
  2. Caliber Trucks Cal II 50° RKP Longboard Trucks - set of two (has a D-Shaped axle that makes placing the motor mount possible) - [$50]
  3. 63mm Motor Mount Set - [$60]
  4. Waterproof Anti UV Storage Tool Box Organizer Case (to hold all the electronics and batteries) - [$16]
  5. Turnigy SK8 6364-190KV Sensored Brushless Motor - set of two - [2x $91.20]
  6. Turnigy 4000mAh 6S 30C Lipo Battery Pack w/ XT90 - set of two - [2x $43.66]
  7. Dual FSESC6.6 Based upon VESC6 with Aluminum Heatsink Mini Size [$200]
  8. Antispark Switch Pro 200A - [$40]
  9. HobbyKing HK-GT2B 3CH 2.4GHz Transmitter and Receiver w/ Rechargeable Li-ion Battery - [$27.82]
  10. 36T Kegel Pulley 12mm Combo Kit - [$26]
  11. Orangatang Kegel 80mm Downhill Longboard Cruising Wheels - [$60]
  12. Bones Reds Skateboard Bearings - [$18]
  13. Longboard Shockpad Risers 3mm - [$4]

For extending the length of wires and securing components:

  1. 20AWG wire- [$8]
  2. 12AWG wire - [$10]
  3. Velcro Tape (Industrial Strength) - [$10]
  4. Electrical Tape - [$5]
  5. 4.0mm Banana Bullet Connectors [$9]
  6. XT90 Connectors - [$13]
  7. Loctite 680 Green Retaining Compound - [$30]
  8. Loctite Threadlocker Blue 242 - [$8]
  9. Solder - [$8]
  10. Heat Shrink Tubing for Wires - [$8]
  11. Skateboard Hardware (to mount electronics housing) - [$9]
  12. 1-1/4" 10-32 Machine Screws and Nylon Lock Nuts (to mount trucks) - [$6]

Tools:

  1. Soldering Iron
  2. Metric Allen Wrenches
  3. Wire Stripper
  4. Adjustable Helping Hands w/ Magnifying Glass
  5. Skate Tool
  6. Power Drill

Projected Cost: ~ $946.54 - $1,086.54

Here is an excellent resource that I used to map out what I needed:

https://electric-skateboard.builders/t/wiki-a-begi...

Step 1: Develop a Plan for Wiring

The last thing we want to do is mess up the wiring and handle the expensive electronics without a plan. I experimented layouts and found that the electronics fit best in the box this way. The idea is to prevent yourself from soldering the wrong thing together and ruining your components. With this plan you develop, you can spend less effort remembering what goes where and focus on the quality of soldering and wire placement.

Step 2: Install Trucks and Electronics Housing on the Board

Alright, now some good ole' labor. For this part, we are installing the electronics housing and the trucks to the board.

The box I ordered had dividers, so I cut and sanded those with a Dremel to make room for the electronics (in hindsight not worth it, so I recommend finding an enclosure with no dividers). I just liked the fact that it is waterproof, has secure locking clasps, and is low profile to maximize space underneath the board.

To install the trucks, the order is as follows:

  1. Poke holes through grip tape where you plan to mount from (the deck should have the holes, so all you need to do is poke through the grip tape and clear the hole)
  2. Place the Shockpad Riser underneath the deck and line it up with the holes
  3. Place the truck underneath the Shockpad Riser to sandwich it between the truck and deck
  4. Places the bolts (machine screws) through the holes and tighten it with a nylon lock nut on the other side
  5. Repeat Steps 1-4 for other truck

To install the Electronics Housing, the order is as follows:

  1. Drill holes into electronics housing where you plan to mount from (usually near the corners of the box)
  2. Make markings on the deck where you plan to drill (using the holes from the box to mark distance precisely)
  3. Drill countersink holes in the deck where you plan to mount (with countersink on the top of the deck)
  4. Use Skateboard hardware bolts to mount the enclosure to the deck and finish it with nylon lock nuts (skateboard hardware provides the flush finish on the deck)

While I had the drill out, I went ahead and drilled a hole on the side of the box to install the power switch button which used a 1/2" hole. The button itself has a screw for a body and comes with a nut to lock in place.

Step 3: Install the Motor Mounts

For this part, we are doing some more labor. Yay!

It's actually not too bad. Prior to installing this piece, you need to determine what kind of drive you want and/or fits on the board (rear-wheel drive or diagonal drive). For my build, I went with a diagonal drive since the motors I chose were too wide to fit side by side.

To install the motor mount, we need to place the locking ring (the small thicker piece with the D-shape hole) on the truck as far inwards as it can go. Then, slide in the mounting plate (the longer piece with the "arc reactor"-looking holes). The mounting plate should be able to freely rotate (allowing you to choose what angle you want it to be fixed at). It's a good idea to place it angled towards the deck to give yourself more room under the deck which prevents the motor from scraping against the pavement. Also, keep in mind the size of the motor and ensure there is some "breathing room" between the motor and the deck in case there is substantial flexing of the deck which may friction burn the wood.

Once you found an appropriate angle, use the supplied hardware to fix the mounting plate to the locking ring (use Loctite 242 Blue to prevent hardware from getting loose). Also, fix the locking ring to the truck by tightening the hardware that clamps it on the truck. (If you know how to weld, it would probably be a better idea to weld the mounting plate to the truck so you don't have to worry about the locking ring loosening over time).

Step 4: Install the Motors

Now it's starting to look like an electric skateboard!

Be careful with these motors, they are heavy and will account for a large portion of the board's weight.

Remember that wiring plan we made earlier? That came in handy since we know how far the wires of the motor should extend. Since the sensor wires on one of the motors were too short, I used the 12AWG wire to extend each of the individual wires and used heat shrink tubing to ensure there won't be any electrical shorts.

With the wiring of the motor ready, we can now mount it on the motor mount. Simply align the holes of the motor with the slots on the mounting plate and screw them in (not all the way, we need to be able to slide it back and forth along the slots for now).

Step 5: Fix the Motor Pulley Gear Onto the Motor Pole Using Loctite 680

Honestly, Loctite 680 saved this build. The motor's pole had a groove for the screw to fix the gear to the motor, but they did not align for these pieces. I thought that I could extend this groove further up the pole to reach the mounting screws, but luckily I came across this stuff which saved me lots of labor. The way it works is that it creates a bond between press-fit surfaces that can withstand extreme rotational force. The only way to remove it is with immense heat (like from a blow torch).

I placed a generous amount on the motor pole, slid the motor pulley in, and screwed in the supplied screws (just for the extra grip). After a few minutes, it already had a strong grip, but I let it cure for 24 hours just in case.

So far, this stuff has held up pretty well.

Step 6: Assemble the Wheels

While we wait for the motor pulley gear to cure on the motor pole, let's assemble the wheels!

Get the bearings, wheels, and wheel pulley gear with mounting bracket and hardware.

Place the bearings on all the wheels. I like to use the trucks themselves to push the bearings into the wheel.

Once that's installed, choose your two favorite wheels. Get the wheel pulley gear and place it on the inside of the wheel (the side that faces the motor mount). Then, get the mounting bracket and place it on the outside of the wheel and align it with the holes on the wheel's core. Get some of that precious Loctite Threadlocker 242 Blue and place it at the end of the screw and screw it into the mounting bracket (making sure it catches onto the motor pulley gear screw holes on the other side of the wheel). Repeat that for all of the screws for that plate and do it all again for a second wheel.

Step 7: Install the Wheels

This is the last mechanical part that we will assemble!

Get your skate tool and the belt that came with the pulley gears.

Begin by installing the wheels without the gear (as you would an ordinary skateboard).

For the wheels with the gear, place the belt on the motor pulley first and slide the motor as far towards the wheel as it can go. Then, slide the wheel onto the axle and roll the belt onto the gear (make sure the belt is straight or you may need to adjust the locking ring from the motor mount). Screw the nuts on the trucks to secure the wheel as you did for the previous two wheels. Finally, slide the motor back and screw it in firmly to provide tension on the belt.

Step 8: Extend Wiring and Install Necessary Connectors

Again, this is where our wiring diagram comes in handy. Knowing where our components will go, we can extend the wires of what we need accordingly.

Solder more wire to what needs extension and cover the joints with heat shrink tubing or electrical tape (if you forget to slide the tube onto the wire before soldering).

For the battery connections, I made a series connector that takes in 2 XT90 connections and combines the inputs in series at the output. This is to make my 2 6S lipo batteries the equivalent of one 12S battery (for higher speeds and power output). High voltage means less current for the same power draw which is good for our wires and reduces heat.

The ESC also has female bullet connectors which I soldered on the ends to connect the 3-phase wires from the ESC to the motor. I would have done a direct solder connection but this gives me more freedom to swap motors if necessary.

Also, the red wire on the ESC 3-phase wires is meant to be black but I ran out of black wire.

Step 9: Place Electronics Inside the Enclosure

Almost done! Let's place our newly soldered electronics into the enclosure.

Begin by placing velcro tape on the inside of the box, we don't want the electronics to bounce around and get damaged. Place the opposing side of the tape on the electronics so they stay put.

Organize the wires and place the components in like in your wiring diagram from step 1. I know it is not as neat but imagine how much messier it would have been if we did not plan ahead! Ideally though, we should aim to make it neater.

Step 10: Program Your VESC

Time to plug it in!

Get your batteries (making sure they are sufficiently charged) and plug them in. Wait a few seconds to make sure nothing bad happens and proceed once everything looks fine. Otherwise, power off immediately!

Use a micro-USB cable and plug the VESC into your computer.

Download and open VESC Tool

Click Auto-Connect so your computer can begin communicating with the VESC.

Begin configuration for your ESK8 setup:

  • Choose motor type: Medium Outrunner (based on weight and what cylinder spins)
  • Choose battery type: Lithium-Ion/polymer 12S 4Ah
  • Choose pulley system gear ratio: 16T to 36T
  • Choose wheel diameter: 80mm
  • Run detection of VESC to run the motors to see if they move in the right direction (invert direction if necessary)

Change the Current settings to protect your batteries!

  • Look up the specs of your batteries
    • The batteries can release up to 30C * 4 = 120 A continuously
      • Of course, we don't want to reach that threshold because we cannot always trust battery specs so we will limit it to 45A per motor, so 90A total max.
    • The max brake current and absolute max current won't matter much as it will be limited by the battery settings we adjust
  • We set the battery max current to 60A which limits all the above current (safety is number one priority and your batteries will thank you)
    • If we want to change that, we can always go back and change these settings
  • Another important spec, the Battery Max Regen which affects braking power
    • When you brake, that energy goes back to the batteries and charges them again
    • According to the specs, the batteries can at most charge at 2C * -4A = -8A (negative because current goes back into battery)
    • So we set that max regen current to -8A (I know I said to go less than the rating, but my mistake with these batteries was not checking this beforehand so I now have pretty weak brakes. I might upgrade the batteries to one with a larger charging current, but we'll see how these hold up.

If everything went well so far, then you are ready to go out and ride your electric skateboard. I hope you had as much fun as I did! Remember to wear a helmet and know your limits (safety comes first)!