[HN Gopher] DIY Onewheel - open-source self balancing skateboard ___________________________________________________________________ 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 ___________________________________________________________________ (page generated 2022-01-04 23:00 UTC)