NOTE:
May 2011: This instructable is now quite old (relatively) and I could now rebuild this project more simply with an Arduino as the controller.
I am currently working on a unicycle with the same OSMC motor controller and an Arduino. When I get that to work I will also add the code to this instructable as the principles will be almost the same (one wheel one motor).
After reading a Make magazine article on the self balancing unicycle of Trevor Blackwell I thought about trying to build a one wheeled skateboard style device. I then found a self balancing skateboard on the net built by Ben Smithers and decided I would definitely have a go at this.
For more information and pictures of my earlier designs please go to:
http://sites.google.com/site/onewheeledselfbalancing
Also:
Trevor Blackwell unicycle and SegwayTM clone: http://tlb.org/scooter.html
Ben Smithers skateboard which inspired me to build this one:
http://www.youtube.com/watch?v=HGbbag9dklU
Also check out this self balancing unicycle:
http://www.enicycle.com/media.html
and this video of same machine from the Gadget Show (wait for the sponsor message to pass)
http://fwd.five.tv/gadget-show/blog/anywhere-anytime-enicycle
Also, many people have tried to build self balancing robots with 2 wheels. There are many on the web. If you do this using a gyroscope, accelerometer, microcontroller and geared motors from a robotics store, you will spend almost the same amount of money as this machine cost to make. The mechanical parts are kart based and often available on ebay. Some robotics mechanical parts are pretty expensive. I thought if I was going to do the "self balancing" thing then I might as well make a robot I could ride!
VIDEO 3/1/09 below.
Video shwing stability and ability to cope with small obstacles. I have since lowered the ride height to make it more controllable in terms of steering at speed.
This is the latest (March 09) lighter weight version with same power as the monowheel but split between 2 motors + same battery power using lighter LiFePO4 battery. Now based on a real skateboard and has 2 wheels so can turn on the spot. Also only 30lb so you can pick it up easily:
May 2011: This instructable is now quite old (relatively) and I could now rebuild this project more simply with an Arduino as the controller.
I am currently working on a unicycle with the same OSMC motor controller and an Arduino. When I get that to work I will also add the code to this instructable as the principles will be almost the same (one wheel one motor).
After reading a Make magazine article on the self balancing unicycle of Trevor Blackwell I thought about trying to build a one wheeled skateboard style device. I then found a self balancing skateboard on the net built by Ben Smithers and decided I would definitely have a go at this.
For more information and pictures of my earlier designs please go to:
http://sites.google.com/site/onewheeledselfbalancing
Also:
Trevor Blackwell unicycle and SegwayTM clone: http://tlb.org/scooter.html
Ben Smithers skateboard which inspired me to build this one:
http://www.youtube.com/watch?v=HGbbag9dklU
Also check out this self balancing unicycle:
http://www.enicycle.com/media.html
and this video of same machine from the Gadget Show (wait for the sponsor message to pass)
http://fwd.five.tv/gadget-show/blog/anywhere-anytime-enicycle
Also, many people have tried to build self balancing robots with 2 wheels. There are many on the web. If you do this using a gyroscope, accelerometer, microcontroller and geared motors from a robotics store, you will spend almost the same amount of money as this machine cost to make. The mechanical parts are kart based and often available on ebay. Some robotics mechanical parts are pretty expensive. I thought if I was going to do the "self balancing" thing then I might as well make a robot I could ride!
VIDEO 3/1/09 below.
Video shwing stability and ability to cope with small obstacles. I have since lowered the ride height to make it more controllable in terms of steering at speed.
This is the latest (March 09) lighter weight version with same power as the monowheel but split between 2 motors + same battery power using lighter LiFePO4 battery. Now based on a real skateboard and has 2 wheels so can turn on the spot. Also only 30lb so you can pick it up easily:
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Here is photo of me riding the first version of this design that I actually managed to get to self balance. This was summer 2008 after a few months of on and off work.
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although a two wheeled unicycle is something i
would love to see.
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!
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!
- bevelled wheel would make turning easier. Would need flat centre section for stability in a straight line.
- 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.
Re Monowheel, yes, this sort of electronics could be linked to the throttle control to prevent "gerbilling" (going head over heels).
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.
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:
http://redmaxmonowheel.co.uk/uniboard.html
Best wishes
John
The twin wheeler is in 2 forms:
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.
See this video:
http://www.youtube.com/watch?v=MyQ-N-pxh10&feature=mfu_in_order&list=UL
Best wishes
john
(£1 = about US$1.5)
Motor about £80
OSMC: Expensive but very powerful - about £160 at the time
Microcontroller £32
Gyro and accelerometer: V Expensive BUT now, in 2010, much much cheaper than they were back when I made this, about £40 for both now.
Batteries: 2 x £30
kart axle, sprockets, wheel, chain all second hand from ebay, about £90
Plus metal sheet, rivets, nuts and bolts.
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.
John
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:
http://sites.google.com/site/onewheeledselfbalancing/
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.
John
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 "you can learn anything to a basic standard after about 50hrs work" which for me has turned out to be true. I know many highly intelligent people who are somehow "unable" to put a shelf up or change a diaper! They are only "unable" 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. I have now put up a parts list and resource guide for you near the start of this instructable. 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.
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 "commit" 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.
Go for it! Stretch your mind. You learn things by experience as well as by being taught.
IMU 5 Degrees of Freedom
instead of aIDG500/ADXL335
IMU Combo Board - 2 Degrees of Freedom - ADXL320/ADXRS150 ?
cheers, ben.Keep up the great work!
CONGRATULATIONS!