Step 14: control system

The microcontroller has to be connected to the motor controller (OSMC) so it tells the OSMC how much power to send to the motor, and in which direction - forwards or reverse. There is a safety signal that tells the OSMC whether to lie dormant or go "live", there are two other pairs of wires controlling the type of pulsed signal to send to the motor. The microcontroller sends a pulse width modulated signal (on and off very fast) at 5V to the OSMC. The OSMC then sends a high power equivalent of this signal to the motor, so controlling its speed. This so called PWM signal is such that the more of the time the +5V is "on" relative to it being "off" i.e. 0V, the more power is sent to the motor. This "on/off" PWM signal cycles very fast e.g. 20KHz which incidentally is why the motor makes a high pitched whine. Here you can see the ribbon cable from the microcontroller running to the OSMC.
<p>hey could you make a quick video showing how to build this awesome project please or if you want you can show you disambling it. First idea will be great please.</p>
<p>Can you suggest some good brush-less hub motor, which will fit to the kart wheel with minimum adoptation?</p>
<p>Excelent instructable!</p>
<p>Look at this Kickstarter: <a href="https://www.kickstarter.com/projects/4422853/onewheel-the-self-balancing-electric-skateboard" rel="nofollow">https://www.kickstarter.com/projects/4422853/onewh...</a><br><br>It's like exactly your idea, but costs $1300. You could've made a lot of money.</p>
<p>Actually they may have raised $650,000 but that is not all spending money, that is as orders for machines. They will now have to honor those orders!</p><p>It was not actually my idea, it was Ben Smithers who first made one of these around 2007, here is the original video on YouTube:</p><p><iframe allowfullscreen="" frameborder="0" height="281" src="//www.youtube.com/embed/HGbbag9dklU" width="500"></iframe></p><p>John</p>
<p>Its $1499 now https://www.trycelery.com/shop/onewheelstore</p>
Could you adapt this system to a one wheeled electric bicycle?
Yes, <br> <br>Have rebuilt this entirely as a one wheeled machine with unicycle seat and it works surprisingly well. I added handlebars which are useful as allows you to shift position more easily relative to the frame to maintain lateral balance and for careful turns. <br>Used and e-bike battery in latest machines. More expense but do not go dead after a year or so like the lead-acids tend to. <br>John
I think BIcycle implies two wheels. maybe electric UNIcycle? lol<br>
everybody makes mistakes man.<br>although a two wheeled unicycle is something i<br>would love to see.
how do I change the balance point. also how to make the soft start softer
man thats wicked, do you think this could be done using a sphere?
the site is very use full thank you and its easy to understand <br>
I really love this thing a lot! Are you working on making a better model? What's going on with it? How's the two-wheeled one going? Why does it go so slow?<br><br>I was watching videos on the McLean McWheel and was thinking how great it would be if the two technologies were somehow combined! If the gyro-balancing were applied to the monowheel, you wouldn't have to be afraid of over-braking and flipping all over the place!<br><br>What if you used 1 wheel but it were more beveled? Would that make turning easier? I'm so going to make one of these one day!
More responses to your questions: <br> <br>- bevelled wheel would make turning easier. Would need flat centre section for stability in a straight line. <br>- Since a rugby ball shaped wheel does not exist you could do this by having 4 wheels on same axle, 2 larger diameter ones in centre with slightly smaller diameter outer ones. <br> <br>Re Monowheel, yes, this sort of electronics could be linked to the throttle control to prevent &quot;gerbilling&quot; (going head over heels). <br> <br>For research of this kind you would need a custom biker type of guy who also can build a self-balancing board and there is one such person I know called Dave Southall. <br>He has built a small McLean monowheel, a diwheel and also a self balancing board. He currently trying to merge the best aspects of all 3 to get some sort of control over the monowheel: <br> <br>http://redmaxmonowheel.co.uk/uniboard.html <br> <br>Best wishes <br> <br>John
The one wheeler has morphed into the &quot;THING&quot; a stand up one wheeled scooter - just to see if it would be possible to ride with 1 wheel - it is just about. <br> <br>The twin wheeler is in 2 forms: <br>An arduino based version built around a proper skateboard deck, and more extreme machine with a deck filled with LiFePO4 cells, pressure sensitive steering and/or wireless Wii Nunchuck control. <br> <br>See this video: <br>http://www.youtube.com/watch?v=MyQ-N-pxh10&amp;feature=mfu_in_order&amp;list=UL <br> <br>Best wishes <br> <br>john
how much did it cost overall
Cost (estimates from memory): <br>(&pound;1 = about US$1.5) <br> <br>Motor about &pound;80 <br>OSMC: Expensive but very powerful - about &pound;160 at the time <br>Microcontroller &pound;32 <br>Gyro and accelerometer: V Expensive BUT now, in 2010, much much cheaper than they were back when I made this, about &pound;40 for both now. <br>Batteries: 2 x &pound;30 <br>kart axle, sprockets, wheel, chain all second hand from ebay, about &pound;90 <br> <br>Plus metal sheet, rivets, nuts and bolts. <br> <br>Remember though, start with motor, sensors, micro, motor controller and see if you can get motor to behave right in response to turning the sensors one way then the other. When you have this worked out (primarily software), spend money on the mechanicals later. <br> <br>John
what if you had 2 wheels side by side, to promote easier turning? as in telling one wheel to turn one way and having the other wheel turn the other?
I have since done this, stripped it right down to the basics and posted an instructable on it. <br> <br>Also have a website documenting all previous versions as I progressed up the learning curve of vehicles with too few wheels, mounted in the wrong place: <br> <br>http://sites.google.com/site/onewheeledselfbalancing/ <br> <br>The attraction of this admittedly strange hobby, is that no matter how much theory you read and how much clever simulation you might want to do, eventually you have to find out what works and what doesn't by actually attempting to build the things. A voyage of discovery. <br> <br>John <br> <br> <br> <br>
XenonJohn... I went through the entire instructable, the idea and your finished piece is quite the accomplishment and is something that not only I but many other people would love to do. The problem is, a lot of people on instructables aren't able to do everything you did, that's why we come here. We can do other people's ideas and learn from them for our own later. without a set materials list or estimated price a lot of us will have to set this idea off to the "someday maybe" pile, which is really a shame. even if you dont want to give one because you think that it'll be different for everybody, it's still nice to have a standard original materials list and estimated price. Thanks for the Idea, hope I can try it out someday.
Hi Lemcott and BuildWiz.<br/>I am not an engineer of any sort and could not program except in BASIC before I attempted this. Incidentally I knew nothing about karting either. The internet provided all the information. Get a big lever arch folder and just spend a month collecting information in each category and educating yourself, before you buy anything. I learned a lesson many years ago that &quot;you can learn anything to a basic standard after about 50hrs work&quot; which for me has turned out to be true. I know many highly intelligent people who are somehow &quot;unable&quot; to put a shelf up or change a diaper! They are only &quot;unable&quot; because they simply do not really want to learn how. Seriously though, no single person will have all the skills required to complete this project. Some will have to be learned along the way. The programmers may be poor at fabrication while those who mess around with old cars will find the fabrication easy and the electronics/programming difficult. <em>I have now put up a parts list and resource guide for you near the start of this instructable.</em> It does not include every nut and bolt though, just the main components you will need. I have also inserted links to example websites for each component. You may well find more suitable or cheaper equivalents if you spend some time on the net and via ebay. Also, if you check out my website (link on first page) you will find I have linked every single similar project from around the world that may be useful to you. This alone was a huge amount of work. Have a look at all of them. Many, as well mine, have software you can study for ideas. When you look at the software of some of the others you will for example realise how I have gone down the KISS (keep it simple stupid) route to get around my limited programming skills. Find ways around your own limitations. I built my machine on the (incomplete) information gleaned from all these sites, I am not the first to build something like this by any means. I hope that this instructable helps others do the same and gets you past some of the major stumbling blocks I encountered. This project will not be easy, but I hope this at least helps save you some time, money and frustration.<br/>The total price for parts will probably not give you much change from $500-700. However do not be put off, it will probably take you a few months not a few weeks to build one of these. Spread the cost out and if you are unsure of your abilities, get the electronics and balance side of it working before you &quot;commit&quot; to buying any of the big mechanical parts, motor or motor controller which are the most expensive. You could even build a balancing model then scale it up - the balance control sytem will be exactly the same.<br/><br/>Go for it! Stretch your mind. You learn things by experience as well as by being taught.<br/>
but thats not what we asked... I agree whole-heartedly with what you have said, problem is it's just non-sequitur to the original request. great speech, but we just wanted an estimated price (or what you actually payed for the project) and a materials list. Thanks for your reply though.
I know. Others read this too however. I don't want people to be put off attempting this just because it seems daunting at first sight. I have tried to provide more than you personally asked for. Hopefully there is now enough information to keep everyone happy, or at least fairly happy. If not, everyone do please feel free to keep sending me questions and I will do my best to answer them.
Excellent points dear author, quite superb. Keep on giving &quot;too much&quot; detail! Better to have T.M.I. [Too Much Information] overall even if some things are left out (like prices) because the variables are too loose to nail down.
is it possable to use a <br /> <h3>IMU 5 Degrees of Freedom<br /> IDG500/ADXL335</h3> instead of a<br /> <h3>IMU Combo Board - 2 Degrees of Freedom - ADXL320/ADXRS150 ?</h3> cheers, ben.<br /> <br /> <br />
More of this type of project from the same guy?? Although I find this whole project to be fantastic, you are starting to make me feel mighty lazy... I have no fewer than 5 &quot;Instructables&quot; projects started and laying around in various stages of unfinished.. You are a true inspiration! <br /> Keep up the great work!
:P were can i get a Go-Kart wheel ........
how do you turn this thing
by leaning
lol it would be easier than turning a regular skateboard<br />
&nbsp;Sos un capo, viejo! (you are great, old!!)<br /> <br /> CONGRATULATIONS!<br />
I'm in the early stages of designing a form of extreme sport transport that could probably use your input on the self balancing of a hubless wheel; too much said already. THEIVES&nbsp;EVERYWHERE&nbsp;I&nbsp;TELL&nbsp;YOU! LOL! but seriously I would love to talk about design possibilities. Ones that are not segway-esque <br />
&nbsp;My compliments to&nbsp;whoever built this thing. I really like the quality workmanship and engineering.
Nice you could probably market this
&nbsp;i second that, this thing is sweet, try contacting some skateboard or bike or something similar company i'd buy it
Copyright infringement would be a problem. The guy that invented the Segway already has a patent on this design. Doesn't keep you from making your own though.<br />
This would be really cool and I think I might do it but the only problem I see is stopping after you've been moving fast. Is their something in there about that?
Hot Wheel, Ha I get it! :P
what the overall cost? sounds like something i need the try out!
First I would like to say thank you for putting up the current instructable. Could you possibly put up a link on how you made the self balancing skateboard : lightweight version?
about how much does it cost to make this?
just 2 technical questions: what is your gear ratio? and with that gear ratio: what is your top speed? how long can you go on one battery charge? I'm just trying to calculate the torque needed and i get to really weird results for the motor you used as in: top speeds of 2 1/2 mph with a decent accelration. so your figures would help a lot. thanks!
did you carry the 1?
? you mean: is there an error in my calculation? could be! i dunno, basically what i did (although like 3 months ago, so i can't really remember all of it) was using an equation for the propelling force of the motor and subtract the friction. then i fiddled around with the gear ratio to get a decent accelration and a decent speed. since not an engineer i'm not really good at this kind of stuff...
This needs a better control. Something like a controller for those electric slot cars would be best. Trigger design gives easy speed control and release of the ttrigger is the deadman switch.
no. you lean forward more and you go faster. that is the cool way. you can do this handfree!
That's pretty awesome! Have you thought about building a hoverboard?

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