DIY Electric Longboard for $300

by comsa42 in Outside > Skateboarding

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DIY Electric Longboard for $300

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Riding a Smartphone Controlled Electric Longboard
DIY Electric Longboard for $300
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An electric longboard is a great way to get around! It’s also easy to make, lightweight, and it can be charged relatively quickly (with the right charger).

This longboard can get up to 32km/h using the motor before it gets wobbly and dangerous. The acceleration is also great, and the controller can be programmed to eliminate any wheelspins that may occur from a standing start. As for range, it can get a solid 10km range on a full charge; however, it is not-recommended to discharge lithium batteries more than 80% as it wears down their life.

A benefit of this design is that the trucks can be put onto virtually any longboard deck. This means that your longboard can be any size you desire. This is a huge benefit for me since I’m using this longboard to get to school and back, thus I need it to fit in my locker.

This longboard has braking and can also be programmed with different acceleration rates.

It also has regenerative braking, sorry for any confused commentators down below!

Want to follow the rest of our electric longboard builds? Here's my blog where I regularly post updates!

Denial Media

Gather Materials Needed

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Longboard Materials:

Hardware:

Small Bits:

  • 6x 1/4" by 2.5" bolt
  • 6x 1/4" - 20 nut
  • 4x M4 by 12mm bolt
  • 4x M4 washer
  • 2.5" washer
  • 2.25" washer
  • 6mm strip of aluminum
  • 4mm banana jack connectors

Where did you get your parts from?

SDP/SI: Large pulley (Part#: A 6L25-040SF0910), small pulley (Part#: A 6A25M014DF0906), timing belt (Part#: A 6R25M057090)

eBay: Trucks, wheels, speed controller, connectors

Hobbyking: Motor, batteries, charger, transmitter, receiver

Hardware store: All of the nuts/bolts, washers, aluminum

Homemade: Longboard deck

Notes:

  • The higher the mAh rating on the lithium charger, the faster your battery will charge. Our 800mA charger charged reaaally slow, so I went ahead and bought a 5A charger.
  • The "strip" of aluminum has minimum dimensions. It needs to be a minimum of 121mm by 51mm by 6mm so the mount can be cut from it.
  • The cost for all of these parts is around $300, which is barely nothing compared to commertial electric longboards

Cutting and Welding the Motor Mount

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Use a jigsaw and a router to cut the aluminum down to the dimensions above. For no particular reason, the back-wheel was chosen to be powered.

The positioning of the mount is important. It needs to go as far back as possible onto the trucks. It also needs to be angled down as much as possible without touching the board (see images above). The positioning was tested with a dry-fit of the motor, wheel, pulley, and belt; then pushing the trucks from side to side to see if it touched the board.

Since I did not have direct access to a welder, I had to temporarily clamp the truck and the mount together with scrap wood so that a professional could weld it. I was worried that the weld would melt the rubber part of the truck, but it came out fine with no problems.

Attaching the Wheel to the Pulley

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The large pulley (40 teeth) needs to be attached to the back wheel. These wheels were chosen specifically because they have 6 holes going around the shaft. It is possible to use this to our advantage.

Six 1/4" holes were drilled 17.5mm away from the center of the large pulley, the 2.5" washer, and the 2.25" washer. I also had to drill a 24mm hole through the center of the pulley in order for the truck to fit through.

Then I put the 1/4" by 2.5" bolts through the pulley, through the 2.5" washer, then the wheel, then the 2.25" washer, then finished it off with the appropriate nuts.

The wheel should still spin freely when put onto the trucks, but now the wheel can be spun with the motor.

Assembling the Motor and Wheel

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Mount the motor with M4 by 12mm bolts (and washers), then mount the smaller pulley onto the motor shaft by tightening the included set screw. There were some problems with the motor skipping inside the pulley so I filed down one side of the motor shaft, then tightened the set screw with some thread-lock.

I pulled the belt over the small pulley, then the large pulley (which was already connected to the wheel). After that, I tightened the truck nut which held the wheel down. Make sure to put the included washers around the wheel!

Hooking Up the Electronics

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The electronics components were connected according to the diagram above.

The batteries were connected in series (plus to minus) by flipping one of the connectors.

The ESC came with two cables which were used to connect the ESC to the batteries.

The ESC also had to be connected to the receiver channel 2. The button that came with the receiver made it easy to turn the whole system on and off, but just for safety, the batteries were unplugged as well.

I made a connector-holder out of wood which came in handy when I needed to solder the banana connectors for the motor. Those connections were finished off with adequate shrink-wrap, to make sure they don't short-circuit.

Hiding It All in a Case

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You can use almost anything in order to protect your electronics from the elements. I had fiberglass left over from a 37 foot catamaran project that my dad is working on, so I rolled with that.

If anyone is interested, here are the steps:

  1. Build a mold, a square was cut out of some foam
  2. Stretch a thin layer of plastic over the mold
  3. Put 12oz. fiberglass over the mold
  4. Pour epoxy and disperse it enough to soak the fiberglass
  5. Throw it in a vacuum bag for 24h
  6. Take it out
  7. Bog and fire the case
  8. Sand
  9. Paint the case
  10. Drill and apply and hatches

Some people also prefer to mount the electronics to the top of the board. This has the added advantage of having more clearance under the board, but it does clunk up the deck...

Some Extras!

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How to track speed and range:

I used My Tracks by Google to track the range and speed of our board. It's a good thing I live in a quiet town; the streets are all empty, and that can be used to set some records!

How to build a deck:

If anyone is interested, I documented the construction of our homemade deck on my blog @ denialmedia.ca

The Proof of Concept Prototype:

One of the first versions of this board ran off the same motor, but used a 1.8Ah battery and a teeny tiny 30 amp speed controller! Unfortunately, I learned about the dangers of over-heating. The controller got so hot, it melted the wiring, causing a short-circuit, bricking both the battery and the controller. Here's a video from before that...

Models:

Included with this Instructable should be a model of the mount that I used as reference for videos and animations.

And that's it! If you are going to build one of these be sure to drop a few images down in the comments, they could potentially help another builder :)

Version 2.0

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After the thorough testing of the first electric long-board, I decided to modify the design and create version 2.0. This version is only 31" long, (unlike the original at 45") and goes just as far, and even faster than the original.

By hooking the batteries up in series, I was able to charge both batteries at the same time. I also modified the original ESC with a really nice toggle switch.

As with the first board, everything was encased in a sturdy fiberglass case, this time featuring solid PVC fittings for the wires and charging ports, as well as a rubber gasket.

Here's the instructable for version 2.0!