DIY 3-Wheeled Electric Skateboard With a Hub-Motor

Recently personal electric vehicles have becoming increasing popular, from OneWheels, to electric scooters and skateboards. I decided to make my own unique 3-wheeled electric skateboard, here is how I did it and how you can make one yourself (on a relatively small budget).

Electric skateboards are a great way to get around, especially in urban areas. However, they are very expensive. Making your own is a great way to cut down costs, and create a more unique skateboard. This one for instance, has two small front wheels and a single large rear back wheel, a setup I have not seen any existing products use.

To understand the advantages of the tri-wheel design I must do some explaining. See the explaining section below.

Explaining Section:

It is time for explaining. Electric skateboards and scooters tend to use either an external electric motor that powers the wheels by a belt, or a hub motor, a motor inside the wheel itself. Each have their own pros and cons, but in my opinion hub motors are superior as they are safer, quieter and allow you to use the skateboard as a normal un-powered board when it is not charged. Furthermore, according to many riders hub-motored powered boards feel more natural to ride. The disadvantage with hub-motor powered boards is that they are less powerful than their belt-driven counterparts.

My 3 wheeled design allows for a large rear wheel, which then means the rear hub motor can be much larger, and therefore more powerful. This means this design achieves equal power to a belt-driven skateboard but also the advantages of a hub motor.

The supplies listed below are what I used, however I list some alternatives in the later steps. If you choose to make this, do your own research into some other options.

The Deck (If you want to make your own - see the "Deck" step)

• Wooden veneers (Longboards are typically hardwoods like maple or oak)
• Grip tape sheet and optional grip tape accent

The Wheels

• A single skateboard truck assembly, including wheels, bearings and trucks.
• Metal L-section or rail
• See the wheel mentioned in the electronics section.

The Electronics

• Electronic speed controller, receiver and controller all-in-one Amazon Banggood £40
• Lithium Polymer Batteries Amazon
• Xiaomi Electric Scooter Wheel with hub-motor Amazon Ebay £50
• 3 Male spade crimp connectors 6.3mm Electrical Supplies
• 3 Male bullet crimp connectors 4mm RS Components
• 2 XT60 Series connectors Amazon
• A reel of wire

The Electronics Housing

• Sheet aluminium
• Laser cut acrylic
• Thin plastic sheet

Various screws, bolts, nuts and other fixings.

Because the board has 3 Wheels, you will either have to make a skateboard deck from scratch or modify an existing one. I decided to make my own.

If you modify one, make sure to get a style of board that has a wide rear, to give suitable space to attach the rear wheel.

If you choose to make your own deck, you can customise to best fit your liking and to best fit the 3 wheel setup however it may not be as strong or as high quality as one you purchase.

Forming the Deck

To make your own deck, you will need several sheets of wooden veneer. Make sure to purchase good quality hardwood, the last thing you want is to spend a bunch of time making the deck only for it to bend or even snap when you try standing on it. Longboard decks tend to be curved, with a concave cross section and sometimes a kicktail (see the diagram below). This adds strength and makes the deck more ergonomic, but is optional. Some longboard decks are just flat, and if you wish to go that route you can skip the sections on forming the curves.

First you will have to cut the wood to size - make a rough rectangle that encapsulates your deck. Glue each of the veneers together. Make sure the glue stretches to the edge of the wood and is consistently spread, otherwise you will compromise the strength of the board. When they are drying, if you want to form curves into the deck you should choose one of the following options.

I laser cut a jig (I attached a .dxf of this), and while the veneers where drying, secured them to the jig with a vacuum bag press, which essentially acts as a 360 degree clamp. If you leave it for a long enough time (I left mine overnight) the deck will dry in the shape of the jig, and be ready to be cut into shape.

If you don't have a bagpress or a laser cutter, I would recommend Practical Projects guide on how he made his skateboard deck using a jig. Obviously the shape is slightly different because his design is for 4 wheels, but the concepts are all the same. Here is his Instructables and his Youtube.

Cutting out the Deck

To cut out the shape of the deck, I laser cut a stencil on greyboard, and drew around it with a pencil. Once again, if you do not have a laser cutter at your disposal you will have to print or trace one out. I have attached the .dxf file of my design, or you can design your own. (The .dxf is a bit weird; a problem I cannot fix)

The design has a lot of fillets for aesthetics, so before I cut out the shape with a bandsaw, I used a pillar drill and a Forstner bit to drill out where the fillet radii where. This is a really great idea if you are using a big bandsaw like I was because they aren't great at tight curves. I then used the bandsaw to cut out the board's straight edges and sanded down any imperfections and splinters.

You can also cut out a handle like I did (see the pictures below) - but I admit this handle is not the most comfortable. The problem is, the centre of mass of the board is quite far back because of the heavy rear wheel. I tried to compensate this with the position of my handle, but did not compensate it enough and the board still tilts backwards when being carried. I would recommend moving the handle even further forward and also perhaps padding it with some sort of fabric.

Grip Tape

There are many options when grip taping a board. I went for black with a yellow accent. To make sure the yellow tape was flush, I cut everything out prior, as seen in the pictures attached. Once the tape is stuck down, just go around the edge with a craft knife or scalpel.

Front Wheels

The front wheels are simple - they are the same as a normal skateboard. I just took the assembly from an old skateboard and bolted it on.

Back Wheel

The rear wheel I used is one from an old wheel motor from a Xiaomi scooter. If you choose something else, make sure it matches your ESC and the voltage of your batteries.

Because of the wheel setup is unique, you will have to make your own wheel mounts, but it is pretty simple metal work.

Another bonus of hub motors is that they are very easy to attach, as the motor spins around the axle, and the axle stays still. My Xiaomi wheel has a simple nut and bolt on either side, so to attach it to the rear of the board I modified 2 pieces of scrap aluminium rail and and milled slots into them. The wheel just slides in, then bolts on, similar to a bicycle wheel. This works great as long as you do it up tightly with a spanner.

I also drilled two holes in the top of the rail to bolt it to the deck (I have no pictures of this sadly. Nevermind these things happen).

I was lucky to find scrap metal that fit what I needed. If you cannot, I would recommend buying some extruded aluminium or steel L section. Make sure the rail is extruded though, not bent as it has to be strong enough to support the wheel and your mass.

Ground Clearance

An important thing to consider is the distance your deck will be from the ground. High ground clearance means it can tackle more rough terrain but makes the deck much less stable when cornering.

This is where things get complicated - you can very much choose different components to what I chose but make sure they are compatible with each other.

Most electric skateboards have 4 basic components:

• Motor - this is in our case the hub motor. The motor I chose is a 36 volt 3 phase brushless motor, which means we will need an...
• ESC - the electronic speed controller... controls the speed of the motor. It must match the voltage of the motor and have the same amount of phases as the motor. The ESC needs power, which means we need...
• Batteries - Batteries are a big rabbit hole, so I will try to keep things simple. You will need a battery or set of batteries that will match the voltage of the wheel and ESC. If you want to choose your own batteries, I would recommend this video by MBoards (however maybe don't buy an MBoards battery pack if you want to keep your board cheap). I bought 3 11.1V batteries, and wired them in series, which means their voltage added to 33.3V; close enough to 36. If you find your batteries will be very expensive, try downgrading to a lower volt motor.
• Receiver and remote control - Finally you will need a way to control the board while riding it. As mentioned below, I did not buy an individual receiver - but if you want to you buy one, there are ones like this one or this cheaper one.

For my electronics I chose an ESC & receiver all-in-one component. This is pretty cool as it comes with an external on/off switch and a battery level indicator, however it is not as high quality or bespoke as if you where to buy the individual components.

The batteries need to be wired in series to reach the required voltage. Simply plug in the connectors to do this, as shown in the pictures. If you use different batteries, you may need different connectors to reach 36V (or whatever the voltage of your motor is).

Annoyingly, the wheel uses spade connectors while the ESC uses bullet connectors. You will need some male spade connectors and male bullet connectors. I went down to the local hardware store, but you can purchase them online as well. Crimp these onto each end of a small length of spare wire and use this like a dongle.

Which wires go where is pretty self-explanatory - colours and plug sockets will match up. Once everything is plugged in, press the button and you should hear some beeping! Now you are ready to test.

To store the electronics underneath the skateboard you will need some kind of housing. I slightly over complicated things, and made quite a big folded aluminium case with laser cut end caps. You can do this as well, and it creates quite a cool looking case, but there are many much simpler options; I have seen some people just use old plastic boxes, but I would recommend 3D printing a case, as it allows it to be a more complex and aerodynamic 3D shape, instead of a big clunky metal box like mine.

Regardless of how you make, it if you make a container out of plastic you may want to leave a hole to expose the heat-sink of the ESC / Receiver (only if your ESC has a heatsink - my one did). My ESC came with a battery level indicator and a external power switch. You will also want to make holes for these, so they can poke out the side.

To attach your electronics case to the deck I simply used wood screws. You could use countersunk bolts, or if you want to be extra fancy you can use threaded inserts like these. These mean you can screw the case into the deck without biting into the wood each time.

Tie your batteries together with a zip tie or something similar, and attach them to the underside of the board or the electronics case with some double-sided tape. In my pictures you will see I made an aluminium bracket - but this was definitely overkill, when a zip tie and some tape would do fine. The ESC I use has holes to bolt it to the case, but tape would work fine here as well.

Screw or bolt on your case and you are done!

All that's left to do is assemble everything and drive!

The board has a top speed of 15mph, like a Xiaomi m365 (which the motor is from). I haven't had time to fully test the range of the board, but people with similar specs have achieved 10 to 15km.