
A guide to building a fast electric skateboard at home - mosfets
http://eskateboard.huu.la
======
allsunny
My suggestion to those of you that are interested in this sort of thing: make
sure you know how to ride a skateboard the old fashioned way first. I grew up
in Southern CA, skateboarding nearly everyday, to school, back, for fun, etc.
There are a lot of basics that you'll want to pick up at slower speeds (how to
bail, dodge pebbles, speed wobbles, slowing down, running from rental cops,
etc). Chief amongst these is "how to bail" (aka as "eat sh!t"). There is, in
fact, a technique to falling softly. The folks saying going 25mph on a
skateboard isn't that big of a deal are full of it, don't screw around with
that unless you know what you're doing. I suppose you can learn the hard way
but if you're 20+ something techie who doesn't have the muscle memory - im
afraid it's not gonna turn out well. Full disclosure: I've never ridden an
electric skateboard but I've heard they're a ton of fun.

~~~
nojvek
I can use a normal skateboard, but there’s no easy way to brake other than use
your legs or “eat shit”. Not great for your knees.

Electric skateboards (one I have) has regenerative braking and it’s amazing.

Being able to control your speed is a pretty big feature.

~~~
kbar13
what about in the case of a hardware failure

~~~
dexterdog
Mine fails over to my hot standby

------
walrus01
> "I have tried Li-ion batteries like Panasonic NCR18650B, LG He4, none are
> not as good as a cheape Li-po batteries you can get from Ebay. "

that's scary as hell considering the battery is likely to take physical abuse.
Look at the number of fire incidents caused by drone LiPo charging. There's a
reason why serious drone enthusiasts charge their batteries in special battery
bags.

~~~
bhhaskin
I think part of the problem is that people just don't know any better. A
battery is just a battery, like any other battery. They don't know that there
are different chemistries and physical properties at work.

~~~
paulmd
I did electric airplanes about 15 years ago, and there were distinct
differences in the quality of various brands and models. Airplane usage is
very intense, during takeoffs and climbs the propeller is under very intense
resistance (effectively stalled) and power consumption is very high. The exact
amount depends on your motor windings and your propeller size/pitch, and
generally the more current the powertrain will push the better the aircraft
would handle.

Started with Sub-C car packs, those sucked pretty badly. Then switched to
HeCell 2/3A (~2000 mAH?) NiMH cells, those had good capacity but weren't the
best discharge rates, they wouldn't do more than 20A peak or so. KAN 2/3AAs
had pretty good discharge rates (could do 30-40A peak) but the capacity sucked
(1100 mAH). All of these types of batteries tended to die after a season or
two of flying, sometimes less than a season, they just couldn't handle that
discharge.

Finally settled on Sanyo 4/5A FAUP 1950mAh cells, they were expensive as hell
(2-3x as much as a cheap pack) but could handle insane amounts of discharge
and had good capacity. They were rated to at least 45A continuous discharge
and in practice could be pushed up to 75A peak loads without issue. For you
whippersnappers, that would be roughly a 40C peak discharge, which LiPos
couldn't touch at that time. They were also the only battery that ever lasted
more than a season without issue, could easily get two and maybe a third with
reduced life.

It looks like they're discontinued, which isn't surprising since everything
has moved from NiMH to LiPo, but if you were doing really intense discharges
like this, they would probably be my cell of choice. I've never seen a cell
before or since that could handle that much discharge. LiPos are not always
the answer.

LiIon is _certainly_ not the answer for a fast-discharge application like
this. They are not really any safer than LiPo, the casing is physically
stronger but they will explode/burn when ruptured just like a LiPo, and they
_do not_ like high-discharge scenarios. Think laptops, not electric motors.
Running a motor this big on a LiIon will end poorly, if you're lucky it will
only be a fire.

------
miquelcamps
A year ago i've launched a directory where anyone can share their DIY eboard
:) [http://esk8builds.com](http://esk8builds.com)

~~~
voxadam
Nice site. On thing I would like is the ability to swipe through the photo
albums.

------
hatsunearu
Oh man. When I had my DIY E-skateboard, it was great fun to play around with
that thing. Great vehicle for me to go to school and back.

Problem is I kept having electrical noise issues that caused my wireless to
cut out. I never figured out how to reproduce it in the lab because it only
seemed to happen under certain circumstances (possibly correlated to extremely
heavy load, but not always). It caused some dangerous moments...

My build used a VESC X (from enertion skateboards, but seems like it was
discontinued). The VESC is a nice open source high current motor controller,
except the FETs they use are in a pretty dumb package, and the VESC X used an
aluminum enclosure that acted as a heatsink for the DirectFETs they used.

I also used 2x 4S batteries[1] used for scale cars, because they had an
integral plastic box that stopped it from getting pelted by rocks and such
(good thing I got it, because I originally mounted it using Velcro and it
fucking dropped during a ride and the battery slid for like 100 feet; probably
would have exploded without the plastic box).

[1]
[https://hobbyking.com/en_us/turnigy-5000mah-4s1p-14-8v-20c-h...](https://hobbyking.com/en_us/turnigy-5000mah-4s1p-14-8v-20c-hardcase-
pack.html)

------
keyle
Very cool but the original board was never designed to go at such speeds. I
suspect you'll ruin the wheels fairly quickly, not to mention you might lose
control at high speed fairly fast. I'm not a skateboarder myself, but I've
moded some bikes and adding speed is the easiest part, making it useful speed
is way harder.

Also, I hope the engine can go in reverse or this guy has no breaking power;
and as he gets comfortable riding it, sooner or later, a surprise will happen
and he will have no choice but jump ship.

~~~
hnaccy
A longboard downhill can easily go over that speed.

~~~
soVeryTired
But then you get speed wobbles...

[https://imgur.com/auUscXX](https://imgur.com/auUscXX)

~~~
hug
What you're talking about is yaw inertia, and as another comment points out
it's solved by moving the weight to the front wheels.

See an explanation here:
[https://en.wikipedia.org/wiki/Automobile_handling#Yaw_and_pi...](https://en.wikipedia.org/wiki/Automobile_handling#Yaw_and_pitch_angular_inertia_\(polar_moment\))

And a 30 second visualistion here:
[https://www.youtube.com/watch?v=4jk9H5AB4lM](https://www.youtube.com/watch?v=4jk9H5AB4lM)

~~~
rhizome
Would that I had that knowledge 30 years ago!

------
franciscop
We need links to the different parts please:

"Motors are relatively easy, just use a wrench to put the wheel in place".

This is only true if you find the right type of motor, which is not easy at
all IMHO.

~~~
edaemon
While I'm not the OP, I can provide the links to the parts I used for my
electric skateboard. The ESC I used is one of those mentioned in the post.

Batteries (x2): [https://hobbyking.com/en_us/zippy-
flightmax-8000mah-5s1p-30c...](https://hobbyking.com/en_us/zippy-
flightmax-8000mah-5s1p-30c-xt90.html)

ESC: [https://www.ebay.com/itm/Dual-motors-longboard-skateboard-
co...](https://www.ebay.com/itm/Dual-motors-longboard-skateboard-controller-
with-remote-ESC-Substitute/302538835504)

Motors: [https://www.ebay.com/itm/90mm-dual-6364-hub-motors-drive-
kit...](https://www.ebay.com/itm/90mm-dual-6364-hub-motors-drive-kit-for-
electric-skateboard-longboard-part/302546262750)

BMS (optional):
[http://www.batterysupports.com/36v-37v-42v-10s-60a-10x-36v-l...](http://www.batterysupports.com/36v-37v-42v-10s-60a-10x-36v-lithium-
ion-lipolymer-battery-bms-p-267.html)

Deck: [https://www.skateshred.com/index.php/wholesale-blank-
longboa...](https://www.skateshred.com/index.php/wholesale-blank-longboard-
decks/36-x-9-5-bamboo-drop-through-deck.html)

This is how I wired them together:
[https://i.imgur.com/tEI4H0E.jpg](https://i.imgur.com/tEI4H0E.jpg)

It's been working really well for me so far.

~~~
voxadam
What wheels and trucks are you using?

~~~
edaemon
They're included with the motors I linked. They're basic urethane wheels with
mediocre bearings. The hub motors require the built-in wheels, but you could
replace the front trucks and wheels with something better.

------
exhilaration
It looks like your text about the battery options is repeated in the middle of
the article.

------
mlevental
the donor board section is just the battery section duplicated. you're also
missing a really important piece (that I actually don't know anything about re
li-po/li-on but do know something about re deep cycle lead-acid) which is the
charge controller (i.e. the thing that prevents your battery from blowing up
and maiming you).

~~~
chaboud
Pleasantly, good speed controllers already have low-voltage cutoffs.

VESC has it, for instance. I believe it’s configurable for cell count, sag,
etc.

~~~
aetherspawn
You need to keep an eye on the temperature too as the cells are not allowed to
go above 60-70C depending on brand before you risk venting.

------
antisthenes
If I'm going 50km/h on something, I would at least like it to have proper disk
brakes like mid-range and higher bicycles do.

Going at those speeds may be fun and all, but you're 1 careless driver away
from the hospital, unless you ride on abandoned roads.

~~~
loeg
Yeah, lack of brakes on a 50 km/h vehicle is a problem. And in the case of
skateboards, lack of handlebars too.

That said, disks aren't essential for good bicycle stopping performance. Good
rim brakes (like most mid or high end road bicycles) stop just as quickly as
disk brakes _in dry conditions_. Rim brakes are not really an option for long
boards, though.

~~~
stinos
_lack of brakes_

Sliding/skidding (where the board is manoeuvred in the direction perpendicular
to the movement) will make you loose speed pretty quickly.

Apart from that motor can be used to brake. Not sure what exactly is needed
for it, but a DIY board I rode once had a dual trigger on the remote, one
direction for moving forward, the other one for braking. Pretty convenient
though won't stop you as quick as some friction brake.

 _lack of handlebars too._

That is only a problem if you either don't know how to steer with the board,
or are trying to take sharp turns at too high speed. Both conditions which are
equally true for other vehicles, main difference being some vehicles will be
able to turn sharper than others given the same speed. And some are easier to
control than others. But enough skill can deal with that.

~~~
loeg
> Sliding/skidding (where the board is manoeuvred in the direction
> perpendicular to the movement) will make you loose speed pretty quickly.

Yeah, but it has the disadvantage of wearing out the wheel surface and
requiring some technique. Any asshole can pretty a brake lever, and brake pads
are cheaper than wheels.

> Apart from that motor can be used to brake.

It can be iff the controller is configured to. I thought I saw another comment
mentioning this article's device is only rigged to go forward. I agree with
you that an electric motor might be a sufficient brake for this application
(at least, better than nothing).

> Pretty convenient though won't stop you as quick as some friction brake.

Yeah, it's hard to beat the mechanical simplicity.

> [lack of handlebars] is only a problem if you either don't know how to steer
> with the board, or are trying to take sharp turns at too high speed

I was talking about braking performance, actually. Handlebars help you throw
your weight back and keep it in the right place for rapid braking.

------
aurizon
A known path, say that multi use path, you can work up to 50 km/h, but on
streets. strange walks etc, you would soon go beyond your ability to react -
been there, fell then, on roller blades at a far lower speed.

~~~
loeg
Yeah, brakes are a good thing for safety.

~~~
edaemon
The ESCs listed in the posted page actually have brakes. I have one of the
ESCs on my board and the brakes are strong enough that they'll toss you off
the board if you don't take some time to learn them.

------
serf
i've used the Vedder ESC (VESC) that is mentioned in this article for robotics
applications.

It's fantastic, and the creator/designer is a great guy who is open to helping
out tinkerers.

It's one of the cheapest off-the-shelf ways to move a bigger hobbyist motor
with encoder support that I've found. Nothing but love for it.

~~~
voxadam
For robotics and other control applications I highly recommend looking at the
Odrive as well.

------
jimnotgym
Is a similar thing possible with a micro-scooter? My son would love this as a
project if anyone has any resources.

~~~
loeg
It's just motors and wheels. No reason it wouldn't be possible with any other
wheeled device. Electronic motors + drivetrain are nice and simple compared to
petrol engines.

~~~
jimnotgym
I was having trouble finding the same kind of hub moters sized for scooter
wheels... The rest looks trivially similar

------
agumonkey
50km/h is suicide.

ps: anybody here owns a gyrowheel ?

~~~
walrus01
50 km/h is pretty common descending a hill on a good quality road bicycle. The
major difference there is that you will have a properly balanced wheelset (a
700C wheelset alone on a decent roadbike, sans tires, are worth at least
$275-350), with gyroscopic stabilizing forces. And you will have _brakes_.
It's also possible on a road bike to aerobrake yourself on a descent by
sitting more upright and adding drag.

~~~
throwaway76543
These boards all use the motor to brake. It's possible to stop pretty quickly.

------
btbuildem
Cool build!

My issue with the powered boards is that the motor is both engine and brake -
they don't coast when you let off the throttle. With a longboard, coasting is
all the fun!

I suppose it would be possible to modify the linkage between motor and wheels
to be one way (drive) only? Kind of like a freewheel on a bicycle?

~~~
lathiat
Thats purely an implementation issue, it's called "Drag". It can be turned off
(in theory) for safety reasons though it's probably not ideal to turn it off.

------
amelius
Still waiting for that hoverboard.

------
jakecopp
I've always wanted to make an electric bike out of an electric drill and their
batteries.

Very easy to source parts, could buy second hand. Could even just friction
drive the wheel with the drill!

~~~
na85
You'll burn out the motor in short order. Drill motors are not designed for
sustained loads.

~~~
jakecopp
That makes a lot of sense. Thanks.

------
mrdmnd
That video is 100% filmed on the multi-use path outside google :D

------
autotune
As neat as this looks I wouldn't build a DIY electric skateboard for the same
reason I wouldn't want to build software for an airplane.

~~~
wolfgke
> As neat as this looks I wouldn't build a DIY electric skateboard for the
> same reason I wouldn't want to build software for an airplane.

You mean for legal reasons? ;-)

~~~
autotune
Heh. Yes, but also because you can only fail forward, literally.

------
aurizon
Hey, hit a curb at full speed and learn how to run at 50km/h in 1/2 a second

~~~
mirimir
More like slide or roll, I think.

I've never been much of a skater. But I've always preferred sliding on my
side/butt to flopping around.

------
trumped
I would need a full body armor to ride that at full speed...

------
raynr
Late to this party, am into this hobby, you _absolutely must_ heed the
following:

1\. learn to ride a non-powered skateboard or longboard first. I guarantee
you, you do _not_ have the balance or skills to ride a longboard at 10kph off
the bat, let alone 50kph. I've snowboarded and wakeboarded for a significant
chunk of my life and I'm telling you, longboarding, especially fast
longboarding, is not an easy skill to master, let alone pick up as a twenty-
something.

2\. allsunny's comment on learning to fall is spot on. You need to know,
instinctively, how to bail at different speeds. At certain speeds and
obstacles you can run off, at others you have to tuck and roll, still others
you will rely on your knee pads or elbow pads to protect you from impact.
allsunny's comment is spot on for other reasons but for now I want to move on
to...

3\. protection! Always wear your protective gear! I wear wrist guards, knee
guards, elbow guards, and a helmet (not full face, unfortunately), every time
I ride. I don't care how good you are, if you are in your mid twenties and
older, a fall on concrete is really going to mess you up. Not that it doesn't
mess you up when you're a kid, just that kids have a greater potential to
bounce back from these things...

OK, now on to the article itself. There's a lot left unsaid, leaving you with
the false impression that you have a proper and informative guide.
Unfortunately, it barely scratches the surface.

(A) Hub vs belt: hubs have more cons than just heat. Hub motors tend to get
really beaten up since your motors are taking the impact of the terrain. The
urethane, or "tyre" part of the hub, is also typically not easily replaceable,
falls off easily, or wears badly. That's kind of changing now but for the most
part if you get a cheap hub you're going to have to replace the whole thing.
Furthermore, the urethane is typically very thin around hub motors and your
ride quality is going to suffer as more vibrations are transmitted up.

Hubs are really quiet, though.

Belt drives have many advantages. The motors get beat up less (unless you
don't have enough clearance). You can "gear up" or "gear down" a belt drive
(albeit not while in motion), giving you more speed and torque options. The
article makes a big deal about dust and dirt and swapping belts but most belt
drives have some kind of cover and belts are cheap to replace. Most
importantly, you can buy wheels from companies who actually know what they're
doing in terms of urethane formulation, grip, comfort, etc. You have _options_
with a belt drive.

They can be really noisy, though.

Remember if you get a belt drive that you need a way to maintain tension. If
your kit doesn't let you do so (e.g. diyeboard kits), it's... well it's not
worthless, but you'll be swapping belts out a lot.

(B) ESCs: there are ESCs, and there are ESCs. The VESC the article author
mentions is indeed open source hardware and firmware, but the quality of the
hardware you get is really hit and miss depending on who you buy it from -
some VESC hardware cannot run in certain firmware-settable modes and will go
up in flames if you try (look up FOC). Furthermore, there are so many versions
of the hardware out there that it can be a nightmare to find the compatible
firmware for it. And finally they're usually expensive as.

On the other hand, the cheap chineseum ESCs have their own set of problems and
limitations. While cheap, they are typically not as configurable as VESCs, and
sometimes lock you in component wise to the vendor's radio control system,
drive and battery combo.

(C) Batteries: do not buy cheap eBay hobby batteries. I've played with these
in the context of RC buggies, planes and drones, and they are really hit and
miss. It is fine in the context of RC toys which you play with in a safe
environment and never for more than a few minutes at a go, it's not so fine in
the context of a moving EV you're standing on going at 50kph, being constantly
hammered by road conditions and put out in the hot sun for half an hour to
hours at a time. Unless you have taken appropriate precautions and screened
the batteries and otherwise know what you're doing, I wouldn't give them a
second glance.

You can look up forums for reliable battery suppliers and make your own cells
or buy from those. If you want to go the DIY route, GA cells apparently do
pretty well, but I wouldn't put a pack together without thinking about cell-
level fusing, having either special soldering equipment or a spot welding
setup, strain relief, wire gauge selection, etc. If you set it up wrong,
you're going to end up with too much current running through too thin a
conductor and having them glow with the heat under load. I've seen it. It's
cool, but also scary... mostly scary.

(D) Oh yeah, you're gonna need a battery charger. What do you mean, you don't
have an adjustable chemistry battery charger just lying around at home so you
can make a choice from a variety of available battery chemistries?

Alternatively you can source a battery management system which is a circuit
matched for your battery chemistry, and just plug it in to a properly set up
power supply. But then you have to ensure the power draw of the drive system
is set up for it.

That said, one potential advantage of having a battery management system is
the ability for you to take advantage of regenerative braking capabilities of
your ESC safely.

(E) Remote control. The article didn't mention this, but you're going to need
one. Please don't buy a bluetooth controller, a signal hiccup at 50kph and
your skin could be a smear on the floor.

Speaking of hiccups, you oughta determine, and set, the failsafe behaviour on
your remote controlled EV. The typical failsafe mode is to freeroll, which
means if it fails you'd better be able to ride and stop your board without
having to rely on the electric crutches. Callback to allsunny's comment.

(F) Deck, wheels and trucks. So you're putting together your 50kph drive and
decide to slap it on a donor deck. So easy amirite?

For heaven's sake don't do this. Longboard decks come in many shapes and
sizes. Again, if you're the kind to have ridden around on non-electric
skateboards or longboards, you'll have a very good idea of the available
options. If not, you have to do your research. The kind of setup that is fun
to ride at 10kph is decidedly deadly at 50kph (look up "speed wobble"). The
wheelbase, deck shape (both lengthwise and cross-sectionally), ground
clearance, softness of wheels, width of truck, stiffness of bushing, geometry
of truck, etc., all make a difference. There is a fair mix of personal
preference and objective necessities too.

(G) Putting it all together. It's not a PC, you can't just plug in the
components and have them work. You'll want to weatherproof the components
somewhat, protect them from impacts. There are also miscellaneous parts you
may want or need like switches, anti-spark connectors, battery level
indicators, etc.

One thing often missed in assembly, for e.g., is that people buy cool looking
carbon fibre decks, crowd their receiver next to the dense batteries or high
current wires, and then wonder why their low powered radio transmitter and
receiver only works intermittently. Not all radios, and not all decks, but
some.

In conclusion: there are a whole lot of miscellaneous matters that aren't
mentioned in the post and I didn't want people reading it to think it was
going to be a single-blog-post level of simplicity to jump on a 50kph electric
skateboard and off you go.

Last word, I promise: 50kph is scary. All of you downhill longboarders who
have earned your way through the school of hard knocks know this. For the rest
of us, 20-25kph is plenty fast and hard to react on if you haven't learnt to
ride on a non-powered longboard or skateboard. Have fun, and take it easy!

------
lesss365
Lifelong skater here. Learn to actually skate. Electric board riders look like
dufuses. Seen quite a few in NYC. Their stances are always way off and
unbalanced, seen many who couldn't stop manually, and it goes
against/disallows for most of the reasons for having a skateboard. You can't
get true ground/board feel while carving, its weight and form prevents
execution of flip tricks, it takes away trial and error learning when it comes
to learning how to skate because you're not actually skating, etc etc etc.

Tired of writing, the main things I wanted to point out are that electric
board drivers look like assholes and eletric skateboards are retarded. It's as
simple as that. Stop using these things and learn to skate

~~~
donkeyd
I used to ride a longboard through the city all the time, not for tricks, but
for transportation, is that wrong too?

Also, electric skateboards look hella fun to me.

Edit: This post reminds me of people laughing at me and telling me I hold my
board wrong, because I 'mall grab'. Why can't you just be happy that people
want to ride a board, there's no need to be a snob about it.

~~~
Relys
Haha, I thought of "mall grabbing" too when I read his post. Electric
Longboards are a totally different application. It's like comparing apples to
oranges. FYI I come from a background with experience in Snowboarding and
Wakeboarding and that's what an eboard feels like except we're not restricted
to water/snow anymore. This is great for people like me who have office
jobs/family and just want to shred for a few hours after work to chill out. I
also had a traditional trick Skateboard when I was younger, but was never very
good and was always afraid of hurting myself. When I go to my local park where
everyone goes for downhill skating I always laugh at the guys on trick
skateboards and penny boards who look like they're going to eat shit at any
moment. I often see some nasty bails and think to myself "well that's going to
eventually turn into arthritis down the road". Hell, even traditional
longboards look scary in comparison to my eboard (which has regenerative
breaks). :) I can bomb step hills (and also climb them ;p) without worrying
about getting pancaked by a car at the bottom. I can literally go anywhere a
bike can go with my eboard. :D I like it better then my bike because I can
instantly switch from "bike mode" to "pedestrian mode" and can drag it into a
store/restaurant with me as opposed to worrying about locking it up and
getting it stolen. I also build/fly drones too, so eboards are a great
transportation method to enable that hobby.

~~~
lesss365
Your "bike mode" point is one I hadn't thought of, and I find interesting.

For the record, I don't hate on longboards in any way. My point was that it
seems that eboards take away from the actual skating experience. It's not a
matter of doing tricks and such, but more about the act of skating. The
balance of body with the board against the force your body exerts, the feeling
of the momentum gained by said force, the ground feel between you and the
board in combination with the pushing foot with ground, and the control and
freedom that comes with it. My feeling is that electric skateboards take away
from the feeling that comes with skating, which is what makes the experience
for most who do. But from observation it also seems to handicap some (not
all), seeing that many appear to be off balance and unable to really control
their electric boards when needing to come to full/immediate stops.

But again I do like your counter point of it being a mode of transportation
that's like a bike in terms of speed and energy costs, but allows for the
rider the convenience of picking up and moving along

