I’ve been commuting by bike for more than 3 years now, and I like it, even if I live in a city where it rains quite a lot… During the last few years, I’ve seen electric skateboards becoming more and more popular and I really would like to try and see if it’s a good alternative to commuting by bike (plot twist, they can’t be used on public space where I live, but it’s tolerated). Unfortunately, the good models are above my budget, but I think I found a solution. (this post is under ongoing edit)
There are tons of electric skateboards on the market, from $200 to over $1000. Buying one is a long term investment for me, just like when I buy a bike. I know some parts are gonna be breaking or will simply worn out, but I know that almost everything is fixable on a bike. What about electric skateboards ?
Even though they are quite simple, I fear that some models might be hard to fix. You would need specific parts that fits your board. What if the company doesn’t sell parts, or even runs out of business ? What if the model is not popular enough to be able to find after-market parts ? I think the solution to all those questions is simple: build your own electric skateboard.
The online community around DIY electric skateboards is actually quite big, I had no idea. It’s super easy to find parts, tutorials, videos… which is just awesome and will make things even easier.
What do I need ?
The list is actually quite short:
- a deck (+ grip tape)
- wheel bearings
- drivetrain (external electric motor, pulleys and belt OR hub motor)
- ESC unit (Electronic Speed Control)
- remote control
The hardest part is probably to get parts that fits well together. Also, the parts required depends on what drivetrain you choose.
Drivetrain types: Hub motor vs. belt and pulleys system
Both have pros and cons. If you’re on a budget, belt and pulleys is the best.
Source: internet, that link in particular
- clean look
- less noise (the motor in inside the wheel and there are less moving parts)
- clearance (just the wheels and trucks, no extra parts around)
- no belt wear/break (of course, there’s no belt…)
- pushing the board is possible (maybe not true with all hub motors though; manually pushing with motors connected can damage the Vesc)
- easier to setup/assemble
- less parts required
- good quality required, price++ (a cheap hub motor would likely break easily)
- wheel and motor is one block (if one breaks, you need to change it all; also, you can’t really choose to use a different motor)
- gear ratio of 1:1
- motors can overheat more easily due to be enclosed in the wheel (which can make them fail)
- people recommend a 2 hub-motors drivetrain (to avoid overheating)
- The wheel material sometimes doesn’t stick well to the motor frame itself
Belt and pulleys
- cheap parts are not always a bad choice (you can buy cheap mount, belt and pulleys with a good motor and be all good)
- can replace each individual part
- adjustable gear ratio (use pulleys with different teeth number)
- more torque (thanks to the gear ratio)
- takes 2 min to remove the belt and have a standard sk8
- single motor drivetrain is ok
- evolvability (each part can be changed for a better one later on; you can even go for a single motor at first and add another motor later)
- better efficiency (link)
- choose your own wheels
- more parts (more work to mount and more prone to something breaking)
- more maintenance
- belt will wear out
- pulleys can wear out (not if good quality though)
- requires some space around the truck and wheel
- requires good ground clearance
Just choose what you like! Isn’t that awesome? You can even buy a used board. There are only 2 simple elements to take into account:
- board height
- board length
Height is important because all the electronics are attached below the board. If your board is low, the electronics might bump into things while riding, you might even get stuck on a bump. On “normal” boards, you can easily add pads between the board and the truck in order to increase the ride height if needed. Drop through longboards, however, will always be a bit lower due to the way trucks are attached to the deck.
Length is also important because of the electronics. A shorter board just means you will have less space to setup the battery and electronic components.
In the end, it all depends on how you want to setup the electronics. Try to get a rough idea of how you would assemble everything, and make sure it fits under the board. A lot of people use longboards because they offer a lot of space, good height and good stability (which is quite important when riding on a road at 40Km/h).
The majority of skate wheels accept a standard type of ball bearing, that is also found in scooters and roller skates. The bearing dimensions are 8 x 22 x 7mm. Bearings quality is sometimes rated on the abec scale. It goes from 1 to 9, 9 being the best. A good quality bearing will provide less resistance and better performance at high speed. Even if this rating system is supposed to give you a overall idea of the bearing quality, you can’t fully rely on it. Always check the feedbacks on a product before buying.
While the common bearings are using steel, you can also find ceramic bearings that will generally perform better. But they are a bit more expensive of course.
The Electronic Speed Controller is the heart of your electric skateboard. All the other electronic components are directly connected to it; the battery, the remote control receiver and the motor. Useless to say that it’s an important part of the setup. A lot of different ones exist on the market, but not all of them can handle the power required for an electric skateboard (voltage and/or amps).
A passionate maker, Benjamin Vedder, wasn’t satisfied with the ESC on the market. So he simply decided to make his own, called VESC. It’s all open source, hardware and software. Because yes, that thing is programmable ! You can find a lot of info on his blog or on the official website. It’s not cheap, but it’s apparently the best ESC ever for electric skateboards. It can support up to 12S batteries.
This forum post contains all that you need to know about the VESC. Basically, the important features that are unique to the VESC are:
- limiting the amount of amps that come from your battery to your motors
- limiting the temperature of the VESC to avoid burning it out
- set a min and max input voltage (min voltage is good if you don’t want to make your battery go completely flat and brick it)
- set a max regenerative break amps (so you don’t send too much amps to the battery)
- set a speed limit
So yeah, the VESC is perfect for e-sk8s and can avoid you breaking or burning your components. However, it’s not 100% safe either, you can burn some components if you’re making too much voltage or amps going through the VESC (voltage: 8V to 50V; current: up to 240A for a few seconds or 50A continous). As VESC aren’t all the same, some are better at handling high voltage/amps. The VESC has a 60k eRPM limit, going over can be dangerous and might fry some components.
As the VESC is open source, several manufacturers are selling it. They are all a bit different, mainly in quality. Some provides extra cooling so they can handle higher power without frying. VESC is now a trademark, so other manufacturers had to officially “rename” their products.
Remote control and receiver
They are often sold together, which makes it easier for pairing the remote with the receive (no frequencies issues and whatnot).
You can find different ones at different prices. However, cheap controllers and receivers can have difficulties in cities where interference can happen and you’ll loose the control of your board. It can be dangerous as you suddenly lost power as your remote disconnects, and then get power again. When this happens and you weren’t prepared, that’s not fun at all. Here’s a nice topic with review on several remotes.
People recommends 2.4Ghz controllers for connection stability. Not sure if there’s a best solution, I recommend looking around and see what eskaters are using (this topic, that topic, or this one… well, you got it, just make some research 🙂 ).
Mainly 2 types: Lithium Polymer (or LiPo) and Lithium Ion (or Li-ion). See this interesting forum post with lots of explanation between the two.
Before buying anything, we have to understand what power we need for our e-sk8.
First, the idea is to get the nicest power output (watts) possible. This means increasing the amps or volts. Increasing the amps will generate higher temperatures, which is not the best (especially in electronics as they are really sensible to that). So increasing the voltage is better. That’s why you put the batteries in series. All electronic components have a max amp and max voltage values, be sure to not go over them.
The usual e-sk8 don’t go over 12S batteries because either the ESC or motor can’t handle more than that.
Cheapest and easiest. Recommended for newbies.
When looking for a LiPo battery, you have to check for its characteristics: the voltage (volts), the capacity (mAh), the number of cells (1S, 2S, 3S, 4S…) and the C rating.
The voltage of a lipo cell goes up and down during charge and discharge. A Lipo cell nominal voltage is 3.7 volts. The minimum voltage for a Lipo cell is 3.0V but it’s not recommended to get them that low, you should try to keep them to 3.4V or 3.3V minimum. A fully charged Lipo cell is 4.2V.
|Battery||Nominal volt.||Full charge||Minimum Volt.||Recommended Min|
|1S Lipo Battery||3.7V||4.2V||3.0V||3.3V|
|2S Lipo Battery||7.4V||8.4V||6.0V||6.6V|
|3S Lipo Battery||11.1V||12.6V||9.0V||9.9V|
|4S Lipo Battery||14.8V||16.8V||12.0V||13.2V|
|5S Lipo Battery||16.5V||18.5V||15.0V||16.5V|
|6S Lipo Battery||22.2V||25.2V||18.0V||19.8V|
|7S Lipo Battery||25.9V||29.4V||21.0V||23.1V|
|8S Lipo Battery||29.6V||33.6V||24.0V||26.4V|
|9S Lipo Battery||33.3V||37.8V||27.0V||29.7V|
|10S Lipo Battery||37.0V||42.0V||30.0V||33.0V|
|12S Lipo Battery||44.4V||50.4V||36.0V||39.6V|
The C rating is the battery pick output capacity. A peak output is meant for being brief, like 10 seconds. Keeping it longer would damage the battery. A 3000mAh (or 3Ah) 20C rated battery means that its peak output is 20×3 = 60Ah.
The capacity means how much energy you can store in the battery. The more you can store, the bigger (in size) the battery is.
Can buy cells separately and mount them together, or buy a pack already mounted. The models used are 18650 cells. Here’s a topic on a 10S 18650 battery build.
A Li-Ion cell nominal voltage is 3.6 volts.
Li-Ion have better lifespan and are safer. You can buy pre-built packages of those or build your own (there’s actually quite a few people building their own for their esk8).
E-skaters like those because you can setup your pack the way you want. People often set them up as a flat pack along the entire deck. It’s not too bulky and give you a lot of range and power.
Keep your battery balanced
As we saw before, batteries are composed of several cells. When you have multiple cells in series, you can just plug your battery to a charger and wait for the charge to be complete. But you can end up with an unbalanced batter, some cells will have a higher or lower voltage than others. And that’s no good (more on battery balancing). Watch that video if you want to learn more about how it works.
To overcome that issue, batteries come with a balancing port. That balancing port has a wire for each cell of your battery, so each cell can be checked and charged individually so they all end up the same voltage when charge is complete.
There are 2 ways of using that balance port:
Those 2 pieces of hardware require an external charger with the same voltage of your battery (if you have a 6S battery, you’ll need a 22.2V charger). The balance charger is programmable and can work with different types of batteries (LiPo, Li-Ion) and different cell numbers (from 1 cell to n cells). The BMS however is often not changeable and needs to be adapted precisely for your battery. It has a huge advantage though: it’s super small and can be embedded on your board. That’s what’s used on all commercial electric skateboards and whatnot, so the user just have to plug a standard charger in, nothing more.
Other things to know
A bit more info about putting batteries in series or parallel:
- Series = multiply voltage
- Parallel = multiply amps
Five 2s 5ah 60c batteries in series = 10s 5ah 60c
Five 2s 5ah 60c in parallel = 2s/25ah/60c
power (in watts) = voltage x amps
About the range, you will approximately use 10wh per kilometre. That an approximation and will change with skate weight, motor efficiency, ground surface, stop/start…
Drivetrain specific hardware
The limitation of options is quite helping here. A motor hub requires specific trucks (well, one specific truck) and specific wheel(s). Those are specific for electric skateboards, so you can’t go wrong. If it’s made for an e-skate, it must means it works properly on an e-skate. Just be careful if you want to buy chinese parts…
Pulleys and belt
That’s the most complex setup, as you have a lot of different options here.
You need 2 pulleys: a motor pulley and a wheel pulley. They exist in different sizes: different number of teeth and different width. The width of the pulley will determine what belt width to use (9mm, 12mm or above).
Common teeth numbers: for the motor pulley, 12 teeth to 16 teeth pulley; for the wheel one, between 32 and 40 teeth.
The gear ratio is the number of teeth on the wheel puley / number of teeth on the motor pulley. E-sk8 usually have a gear ratio of around 2.2 (36 teeth wheel pulley, 16 teeth motor pulley for instance). A big gear ratio gives more torque but less speed, and vice-versa for a small gear ratio. Electric motors have a tendency to go quite high in RPMs, which is useless for an electric skateboard that goes around 25km/h to 40km/h. That’s why we want to reduce speed, which will give us more torque.
Of course, the motor you’ll choose depends on the type of setup you want to make. Motors for a belt and pulleys system won’t work for a hub motor system.
This is a quite complex subject actually, even though it’s just maths formulas. If you feel adventurous, I found a pretty awesome calculator for electric motors efficiency.
The motor can have a sensor, that needs to be connected to the ESC. From what I read, a sensored motor is better because it’ll be smoother an acceleration, won’t twitch when starting from dead stop, and it’s less noisy (see that topic for more). But it apparently reduces the motor RPMs when going at high speed. Also, using a VESC provides smooth start as well (not a smooth, but still). Or you can just push you board once when starting and you won’t have any issues.
The easiest way to determine what you need is to look at what the majority of builders are using.
eRPM = (voltage)x(kv rating)x(7 pole pairs, for most 50-63mm motors)
motor kv means rpm per volt.
200kv means 200 rpm per volt
200kv x 42v = 8400 rpm
190kv x 42v = 7980 rpm
I found that a lot of people are using 190kb motors.
If you have a VESC, you need to get under the 60k eRPM limit (see this topic). That’s quite easy to calculate, here are some examples:
- 190kv motor with 12s battery (12 x 3.7 = 44.4 volts); 44.4 x 190 x 7 = 59 052 eRPM so we’re good
- 200kv motor with 12s battery; 44.4 x 200 x 7 = 62 160 eRPM, that can be dangerous for your VESC.
- 200kv motor with 10s battery; 37 x 200 x 7 = 51 800 eRPM, so we’re good.
I found a nicely detailed guide of how your battery, motor, pulleys are working together. Basically: the wheel diameter, battery voltage & motor kV all work together to determine the top speed you can reach.
About anti-spark loop key.
If you’re not sure what to buy, here’s a list of commonly used parts for e-skates.
Where it makes sense than quality parts are often the most expensive, there are some parts that don’t really need a high quality finish.
Going for a belt drive / pulley system ? You can find very cheap deals coming from China, check Ali Express or Banggood.
Pulley, drive, belt and motor mount for $25 on AliExpress
Pulley, drive and belt for $22.27 on Banggood
Amazon also have cheap stuff too.
Make sure the mount fits your truck and the pulley fits your wheel.
Some specialized sites are selling everything you need. There are even kits where everything just goes together and you just have to mount them to your board.
- A DIY builders created an awesome remote
- Custom all aluminium motor mounts ($50)
- http://www.skateshred.com (cheap boards)
- http://www.diyeboard.com (chinese products but they are serious, see this topic for feedback)
- https://hobbyking.com for batteries
- https://goaxle.com/ (only for the VESC)
Because it’s not easy to find parts in the country of poutine and maple syrup.
Electric Skateboard Builders (community of builders, if you have questions, this is the place to go ! Some members even produce their own parts; that topic contains a lot of things you need to know; that topic is a newbie trying to get his head around his first build)
ElectricSkateboarding Reddit (about esk8 in general)
High performance good quality build esk8; this is not for newbies though and it’s quite expensive. It has dual drive, Li-Ion custom made battery, and it can reach high speed (almost 50Km/h!)
esk8builds.com is listing builds made by different people around the globe. Can be a good source of inspiration.
esk8race.com has leaderboards for the longest and fastest rides
A very detailed blog post about each element of an esk8 build
Got a problem with your ESC/VESC ? drvwizard might be able to fix it
A very complete tutorial about building an electric mountain esk8
A good calculator to get your speed and approx. range
A lot of people are building custom esk8, there’s a ton of videos on Youtube. Here’s a quick one with a very simple setup but it gives a good preview of the work and parts needed.
Here’s another one with the same content. The more video and tutorials you see, the better you’ll be prepared !
In order to track your speed, distance an so on, you can easily use any bike tracking app available on any smartphone out there.
A dude is creating its own app, see that thread. You need to get a bluetooth emitter (HM-10 bluetooth module), connect it to your VESC and then connect your phone to the bluetooth emitter. This will give you more data like battery percentage, temperatures and maybe more (I haven’t looked at that topic deeply and the app isn’t out yet by the time I’m writing this).