[HN Gopher] DIY Onewheel - open-source self balancing skateboard
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DIY Onewheel - open-source self balancing skateboard
Author : johnsonap
Score : 117 points
Date : 2022-01-04 17:28 UTC (5 hours ago)
(HTM) web link (www.bytesizedengineering.com)
(TXT) w3m dump (www.bytesizedengineering.com)
| vanous wrote:
| This is cool and horrifying at the same time, just be very
| careful if you are trying such a thing.
|
| We just had an initial support for VESC NRF/HM10 devices added
| into Gadgetbridge if this is of interest to anyone fascinated in
| this subject.
|
| https://blog.freeyourgadget.org/release-0_64_0.html
| tyingq wrote:
| Managing the size of the gaps between the wheel and the
| platform seems like one safety centric issue. Too narrow and it
| can suck up some skin into the narrow hole. Too wide and it
| pulls in a whole shoe, or leaves not enough flat surface. I'm
| curious what the optimal size is, and whether there are more
| ways to safeguard it.
| johnsonap wrote:
| Yeah I was noticing how wide the gaps were on his
| dghlsakjg wrote:
| As the owner of a commercial onewheel, The gap is pretty
| small on those. Maybe 1/4".
|
| However, the real solution is to just get a fender since
| riding on anything but clean pavement leads to a lot of dirt
| being flung around.
| 71a54xd wrote:
| I like one-wheel type devices but will always prefer electric
| unicycles. They have more range [0], more safety over large bumps
| (due to a larger wheel and facing forward) and are easier to
| carry around when you're walking. Unfortunately, due to liability
| laws in america most of the EUC manufacturers are based in China.
| I CANNOT wait for an american company to start producing EUC's!
|
| I learned to ride an InMotion V8 [1] during the pandemic, and
| although there was a significant learning curve, it's now my
| favorite way to get around new york city. Definitely wear a full
| face helmet and wrist pads though if you decide to learn to ride!
|
| 0 - https://www.youtube.com/watch?v=h1aRPKyjzj0 1 -
| https://www.ewheels.com/product/new-inmotion-v8s-728wh-batte...
| sbierwagen wrote:
| >As far as the battery goes, the XR has a 324Wh nickel manganese
| cobalt oxide battery (that's a mouthful!) while the one I built
| has a 960Wh Lithium Ion battery pack.
|
| NMC is a type of lithium-ion battery. The cell voltage of the
| ebike battery he's using is 3.7v, which means it also uses NMC
| cells.
| [deleted]
| tyingq wrote:
| Ah, yeah. Seems a bad communication consequence of Lithium-
| Nickel-Manganese-Cobalt-Oxide (LiNiMnCoO2) going by the "NMC"
| nickname.
| pengaru wrote:
| FFS someone please convince the author of this page to recompress
| these photos using high compression and a lossy format like jpg.
| Over a minute and still not loaded here.
| gtm1260 wrote:
| Skeptical at first but this thing looks pretty sweet. Total BOM
| estimated at ~700$, and similar performance to the 2500$ onewheel
| XR it seems!
| foreigner wrote:
| I never understood why these self-balancing toys are so
| underpowered. I want to see one built on top of a dirtbike engine
| that you need to wear serious body armour to use.
| micromacrofoot wrote:
| Have you ridden one before? I hit 15mph on a onewheel once and
| have no desire to ever do it again.
| bredren wrote:
| I rode 100 miles on one two years ago, and planned to take it
| to the Burn but after my second fall I decided to sell it and
| get a Space Horse from All City.
|
| I was padded up for both falls but still sustained a sprain
| to an ankle and some pretty mean scrapes to my shoulder and
| arm.
|
| My worst fall was due to the motor cutting out on a moderate
| acceleration uphill climb from stop. This is not unusual on
| the OW but is normally associated with a lower battery level.
|
| I was pretty good with it, but in the end I could justify the
| potential for falls once every 100 miles, let alone 50.
|
| They are fun to ride, though.
| MivLives wrote:
| I put about 2400 miles on mine. You fall a few times in
| your first 100-200 miles but after that it really doesn't
| happen much, and normally only when you do something
| stupid.
| gregn610 wrote:
| Have you seen the original Australian bushpig?
|
| https://youtu.be/0OV33C2JgIE
| frankus wrote:
| There are a lot of practical problems trying to build a
| balancing vehicle around an internal combustion engine.
|
| They can't produce any torque at zero speed, they can't
| smoothly reverse direction, they likely can't produce enough
| negative torque at higher speeds, and their control bandwidth
| is probably inadequate for anyone but an extremely skilled
| rider.
| gnopgnip wrote:
| You are limited in how fast you can safely go by how fast you
| can stop
| blacksmith_tb wrote:
| Well, they already have a reputation as pretty risky to
| ride[1]. I am sure you could scale the motor and wheel up some,
| but I'd want some wearable airbags...
|
| 1: https://dailyhornet.com/2021/onewheel-lawsuits-pile-up-
| after...
| johnsonap wrote:
| Wow, I never knew folks had died on these
| xboxnolifes wrote:
| If something moves, and someone rides on it, someone has
| probably also died on it.
| johnsonap wrote:
| very good point, I was more talking about the cause of
| death being a defect
| howdydoo wrote:
| But was there actually any defect? Anyone can claim
| anything in a lawsuit.
| bredren wrote:
| There is broad consensus that the One Wheel could do more
| to warn riders of an impending nose dive.
|
| For example, an audible tone the moment it shuts off the
| motor while underway.
|
| There are other design changes that could reduce the
| danger of a nose dive that 3rd party manufacturers have
| pounced on including small wheels that allow the product
| to potentially slow instead of come to a dead stop when
| an edge hits the ground.
|
| I don't know what product liability is for continuous
| mounting evidence that an existing design is lacking
| obvious safety feature and choosing not to make changes
| or acknowledge this.
|
| But I suspect ultimately this will end in a class action
| suit.
| howdydoo wrote:
| Interesting. I bought the original model when it was new
| and I've been happy with it. I always just viewed it as
| something that was inherently risky, but worth it. The
| board does have a way of "communicating" with you when
| you're pushing it too hard, by leaning you back, and it
| seems pretty intuitive to me. Then again I used to be a
| skateboarder, so maybe my risk tolerance is outside the
| norm.
|
| I assume these are the wheels you're talking about[1].
| Pretty ingenious idea, although it does mess with the
| look of the board
|
| [1]: https://www.etsy.com/listing/1069745398/onewheel-xr-
| safety-w...
| bredren wrote:
| The risk tolerance of skateboarders is probably the gold
| standard.
|
| Expectations for safety have changed a lot,too. I raced
| ski team in high school. Helmets were optional and very
| few rec skiers wore them.
|
| Now it seems unusual to see someone without one.
|
| I'm aware of the haptic feedback the board is supposed to
| give when it is getting tired, though there are many
| claims of it not being produced prior to a nose dive.
|
| Yes that product you linked is what I was describing.
| Note their description describes nose dives on the OW as
| "inevitable."
| johnsonap wrote:
| Thank you for the context!
| MisterTea wrote:
| > For example, an audible tone the moment it shuts off
| the motor while underway.
|
| If it has the ability to monitor battery life then it can
| certainly do stuff like emit an impeding dead battery
| warning tone and then gently decelerate to a stop.
|
| Though I bet its an issue where the battery level is
| simply monitored via voltage. So lets say a 15% charged
| battery has enough current to push the rider along on
| level ground, BUT, the moment the rider hits an uphill,
| the current increases beyond what the now weaker battery
| can provide, the voltage drops below the battery
| threshold and the battery protection circuit shuts down.
| Very unsafe design.
|
| A proper design would allow the battery and motor drive
| to cooperate so when the motor current demand rises to
| maintain velocity, the battery pack can tell the motor,
| sorry, I cant give you anymore and the motor drive can
| then decelerate or simply refuse to continue
| accelerating.
| bredren wrote:
| > A proper design would allow the battery and motor drive
| to cooperate so when the motor current demand rises to
| maintain velocity, the battery pack can tell the motor,
| sorry, I cant give you anymore and the motor drive can
| then decelerate or simply refuse to continue
| accelerating.
|
| These are good thoughts though even in your solution I
| suspect it points toward the idea that the design is
| fundamentally unsafe.
|
| The reason is if the motor decelerates you still must be
| prepared for your weight to shift, even gradually.
| miskin wrote:
| The main problem is that to push you back, the motor
| actually has to go faster to get in front of your center
| of gravity and this is exactly what is hard when the
| battery is getting weak. That's why nosedives often
| happen when users want to go too fast, ignoring the
| pushback from the wheel and actually "rinding the
| pushback". At some point, the motor does not have enough
| torque to counter the push down on the front and give up.
| This causes the front side to collapse and we can all
| imagine possible results when feet "want" to stop and the
| head is going 20mph+. It's not that battery management
| will simply turn the device off (although it may also be
| an issue in some cases). Usually motor just becomes too
| weak to counter rider push for a short moment and the
| front part of the board hits the ground.
|
| I do not have experience with Onewheel XR, but pushback
| on the Pint series is rather noticeable and hard to
| ignore when you hit set speed limit. Onewheel XR is said
| to have weaker pushback.
| johnsonap wrote:
| you make a valid point
| mystickphoenix wrote:
| What you're looking for is an EUC, Electric Unicycle. Most of
| the people in the local onewheel group I'm a member of that
| ride EUC's wear _full_ motorcycle protection. At least one of
| them can go upwards of 45 mph.
| johnsonap wrote:
| Holy shit I just googled EUC's, those things look insane
| Glide wrote:
| They are insane. I bought one and learned how to ride it.
| It took a while and it was very frustrating before it
| clicked.
|
| It's surprisingly intuitive once you get going.
| karmicthreat wrote:
| They can be pretty dangerous if you are an idiot. IE this
| crash: https://www.youtube.com/watch?v=pahL4MPPOek
| smithza wrote:
| I am sure that man has many hours of safe riding. It is
| always the 10 seconds of deadly and uncontrollable trauma
| that necessitates safety gear. Self-confidence is often the
| hubris of humanity.
| bicx wrote:
| I ride a OneWheel and it can test your nerves sometimes.
| However, just looking at the speed and stance of a EUC makes
| me more nervous. You could just open your arms at 45mph and
| embrace the car in front of you.
| zardo wrote:
| I don't think the go-kart wheel in the middle of a skateboard
| layout would make for a good ride above ~35mph. Too twitchy in
| yaw and too limited in braking power by the geometry of the
| thing.
| MivLives wrote:
| It's for legal reasons in a lot of places. Most places have
| laws about the max speed of motor powered devices. It's
| normally around twenty.
|
| I've gone up to 24 MPH (on flat) when I had one, and have hit
| the ground going twenty. I'm honestly not sure more speed is a
| good idea as it just takes one little crack in the road you
| weren't anticipating to throw you balance off.
| michaelt wrote:
| Single wheel vehicles have no brakes worthy of the name.
|
| After all, when you brake hard with a car or motorbike or
| bicycle, it's the front wheel, well in front of the centre of
| mass, that does almost all the work.
|
| In a single wheel vehicle, the wheel well in front of the
| centre of mass.... isn't there. In a unicycle that means you're
| flying off the front (it's even worse in a monowheel) so you'd
| better not be going faster than a man can run.
| Groxx wrote:
| ... which is why you lean back on these to brake, to shift
| your center of mass back so the wheel can slow you down. same
| thing in reverse for accelerating, otherwise you'd see people
| fall off non-stop at the beginning for the same reason you
| claim they can't stop.
|
| your stopping speed is limited by how fast it can decelerate
| you, which is essentially the same as how fast it can
| accelerate you. it's not super fast to stop, to be fair, but
| neither is a bicycle going at high speed (though I'd expect
| the bike to be a little bit quicker to stop).
| MivLives wrote:
| If you need to stop super fast you lean back so hard you're
| actually dragging the tail. There's a reason a lot of
| people put additional plastic armor on the bottom of these
| things.
| masukomi wrote:
| this is cool, BUT as a onewheel owner who's spent way too much
| time learning about them and the knock-offs, it's not the
| hardware that's the tricky bit. It's the software.
|
| the knockoffs are NOT GOOD and thus even _more_ dangerous to ride
| because no-one else has figured out how to get the balancing
| software right.
|
| so, yeah, if you go into this project, know that regardless of
| how awesome your hardware skills are, the software is the bit
| that's _really_ going to take a lot of time if you want an
| experience anywhere close to the official one.
| transistor-man wrote:
| Nice video series!
|
| With some incredibly odd timing, I documented building a onewheel
| right before the commercial ones existed, for a 2014 writeup:
|
| https://transistor-man.com/flying_nimbus.html
|
| So jealous that off the shelf hub-motor in wheel assemblies exist
| now, i had to build a custom hub and dealt with the oddities of
| planetary backlash, then ended up fitting an early direct drive
| motor.
| osamagirl69 wrote:
| It really is amazing how much the state of the art in hub
| motors has come since 2012. Building silly electric vehicles is
| almost too easy now that you no longer need to wind your own
| motor and write your own bldc commutation firmware...
| dbspin wrote:
| 'incredibly odd timing'. I pray that I live long enough to
| develop such equanimity, assuming you got ripped off.
| s5300 wrote:
| https://forum.esk8.news/search?q=Onewheel
| btreecat wrote:
| Love it! I just got a PintX and have been learning how to shred
| on it. But naturally I was curious how much work would go into a
| DIY model.
| MivLives wrote:
| I'm sorta terrified of this. I know more then one rider that
| broke bones, or got other injuries from the official version of
| these just randomly conking out. A DIY version made by a lot of
| people seems even more likely.
|
| Also seems super inconvenient to move around. The XR was already
| annoying to take into shops as it was heavy and long. This is
| heavier and longer. Though the extra weight might smooth out the
| ride a bit. Surprised he went for a smaller tire. I feel like a
| larger one would take bumps better.
| JPKab wrote:
| Agreed. As a longtime rider, I will unequivocally state that
| 95% of serious injuries on these things are from new riders who
| get overconfident (and ignore every single piece of advice on
| the website and on the tons of Youtube channels) and suffer
| nosedives when their small muscles in their legs (and nervous
| system as well) experience fatigue and trigger involuntary
| tremors. (any rock climber here will know what I'm talking
| about: When you see a newb climber getting this fatigue and
| their leg starts shaking like Elvis...)
|
| The smaller wheel is a bad idea. Period. Can't fault the
| heavier weight though. Future Motion machines their aluminum
| rails from single billets. It's not something that you can
| replicate easily without tremendous capital expenditure.
|
| I'm planning on buying the new GT soon, but it's even heavier,
| and my god is it awful carrying those things around.
| JPKab wrote:
| I'm a daily rider of a Onewheel XR. I've got a few thousand miles
| on mine, and I do a ton of trail riding here in Colorado. I'm
| pretty obsessed with these things.
|
| All that aside, I would advise anyone who wants to try going this
| route to watch their ass.
|
| A standard Future Motion developed Onewheel is an extremely
| dangerous device. I always, always wear a helmet on mine. If you
| wear a helmet, the device pretty much stops being fatally
| dangerous, and just becomes a source of rather mild injuries
| if/when you fall. I rarely fall on mine now, and when I do, I
| don't get injured due to standard skateboarding/mountain biking
| pads. All that being said, FM put a TON of energy and learning
| into their firmware. A onewheel that cruises on a smooth surface
| is relatively straightforward compared to one that can be
| reliably ridden in rough conditions, handle bumps/voltage
| sags/etc gracefully, and just be super durable as well.
|
| I could definitely see an open source onewheel eventually
| becoming on par with FM's XR. But if you're an early adopter of
| this thing, be ready to fall, A LOT.
| frankus wrote:
| If you're remotely interested in this sort of thing, definitely
| check out the VESC project (https://vesc-project.com), which is
| kind of the secret sauce that makes this sort of thing accessible
| to mere mortals.
|
| There are a lot of hardware variants at different price and
| quality points but it's a great, hackable, open-source (GPL3)
| motor controller for smallish motors (in the 24-44 volt range--
| they typically use a gate drive/power supply controller with a
| 60V limit).
| amelius wrote:
| I personally prefer walking 30 minutes over standing still for 10
| minutes ...
|
| Never understood the Segway either.
| fossuser wrote:
| The OneWheel is great in SF, I can take it 1.2mi to drop
| something off at the UPS store and back in 15min.
|
| Doing this with mass transit would take an hour, walking would
| take an hour, driving would be a pain because of parking.
|
| It's great for all sorts of little trips like this, probably up
| to a 6mi round trip (I have the pint).
| JPKab wrote:
| Haha, fair point. To be clear, the production Onewheels are a
| very good workout to ride. Unlike a segway, they require a lot
| of balance and hip/leg movements. Additionally, they are
| extremely maneuverable. I ride mine on mountain bike trails
| here in Colorado. Not sure you are into mountain biking, but
| one of my favorite aspects of riding is hitting the berms at a
| moderately high speed and cruising up the wall like i'm riding
| in a pool at the skate park.
|
| You get sweaty as hell, and new riders can only ride for short
| periods of time before suffering lots of fatigue in
| feet/legs/hips.
|
| Edit: One of my favorite trail riding videos on onewheel
|
| https://youtu.be/_jyAGgaxPv4?t=25
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(page generated 2022-01-04 23:00 UTC)