You are never to old to learn and try new things. I think one of the best days in my life was the day I discovered the Instructables web site. It opened up a whole new world to me. This is my third instructable . I really enjoy building anything that I can ride on or get in to.
I bought an Arduino Uno and was planning on building a balancing Robot. I was really impressed with the Balancing Skate Board that was published by Xenon John. It had most of the code that I would need to build a balancing something. That something evolved from a Robot to a Sit Down Segway clone, which I named the SITWAY. I want to at this time thank John for all the help and patience he showed me in building and testing this ible.
This is my second project involving a discarded electric wheel chair. The motors have great torque and are very reliable. They use 24 volts and have great range using two U1 type garden tractor batteries. You can't go any cheaper than that.
The build went pretty smoothly. Thankfully Xenon John pitched in and helped me modify his code to work with my wheel chair motors.
After running all the tests I felt were needed I elected to have a young neighbor take the first ride. It turned out to be a real blast. So far eight or ten people have ridden it, the youngest being 12, and the oldest 81 (me). The training wheels limit the speed by limiting the forward tilt. I plan to keep the rear training wheels on permanently because I don't need a lot o speed going backwards.
The SITWAY appears to be pretty safe, but it does not have all the built in backup systems that a real Segway has, I have only tested it on my smooth driveway at this time. I have driven over small objects, and it still stayed stable..Any one can learn to drive it in about 5 or10 minutes. With all the testing and driving we have done I have yet had to charge the batteries. The original wheel chair had a published range of 20 miles.. HAVE FUN!!!
I bought an Arduino Uno and was planning on building a balancing Robot. I was really impressed with the Balancing Skate Board that was published by Xenon John. It had most of the code that I would need to build a balancing something. That something evolved from a Robot to a Sit Down Segway clone, which I named the SITWAY. I want to at this time thank John for all the help and patience he showed me in building and testing this ible.
This is my second project involving a discarded electric wheel chair. The motors have great torque and are very reliable. They use 24 volts and have great range using two U1 type garden tractor batteries. You can't go any cheaper than that.
The build went pretty smoothly. Thankfully Xenon John pitched in and helped me modify his code to work with my wheel chair motors.
After running all the tests I felt were needed I elected to have a young neighbor take the first ride. It turned out to be a real blast. So far eight or ten people have ridden it, the youngest being 12, and the oldest 81 (me). The training wheels limit the speed by limiting the forward tilt. I plan to keep the rear training wheels on permanently because I don't need a lot o speed going backwards.
The SITWAY appears to be pretty safe, but it does not have all the built in backup systems that a real Segway has, I have only tested it on my smooth driveway at this time. I have driven over small objects, and it still stayed stable..Any one can learn to drive it in about 5 or10 minutes. With all the testing and driving we have done I have yet had to charge the batteries. The original wheel chair had a published range of 20 miles.. HAVE FUN!!!
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Signing UpStep 1: MATERIALS AND COSTS
Item Source Cost
1. Donor electric wheelchair Various places $50 to $200 Depending on condition
2. Arduino Uno Maker Store $30
3. Arduino Uno Proto-shield Spark Fun $15
4. 5 degrees of freedom IMU Spark Fun $49
5. Sabertooth 2X25 Dimension Engineering $129
6. Two surface mount LED's Radio Shack $1.29
7. Two Momentary contact switch's (trim) Radio Shack $1.29
(normally open)
8. Two micro switches for Steering Radio Shack $3
(normally open)
9. Single pole single throw power switch Radio Shack $1
10 13X20X1/4" plate for base Local $10
11. 1/2" steel tubing for seat frame Local $10
12. Vinyl and foam for seat Local $4
13. Asst hook up wire Local $3
14. One can spray paint Local $3
Total $309 to $459
(note) I actually bought my used wheelchair for $35 at a yard sale
It was pretty beat up but the motors were good and even included
A 24 volt charger.My project cost less than $300.
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I am trying to build a self balancing scooter for my son, But here in India I am not able to find Sabertooth 2X25. So trying to figure out a way using high power transistors (2N3055) to drive motor. Will share the details once I am through with it.
I wanted to know how is the motor connected to the wheels. If possible please share the images of motor connected to wheels & also the specifications of the motor.
Once again thanks for sharing.
I have just bulid the hardware for self balancing electric skateboard using Arduino Uno to control with 5DOF IMU (IDG655 ADXL33). I have encouter some problems: -
1. When I tilted the scooter too much, it will fly off. Is there any code in the program to prevent the scooter from flying off if it is tilt too much?
2. When the scooter fly off, it took quite a bit of time to ârecoverâ to it balancing position if I were to tilt it to the opposite direction. Anywhere in the code where I can change to have the scooter tilt back faster?
I am using code from XenoJohn from instructables website. Please help.
Thanks.
Sparkfun IMU Part # SEN-11072 is retired now 03/18/2013. I'm very appreciated if you have other to replace it. Thanks
Mickydee
I read your project and very impressive to me. Today is 03/14/2013. I can not find 5 degrees of freedom IMU from SparkFun. I already have wheel chair motor, Arduino Uno, Sabertooth 2X25 etc... Can you help me, where can I find 5 degrees of freedom IMU or something replace it. And the code to work with.
Thanks, have nice day.
Good luck on your project. I am working on an improved machine and it should be ready soon
Mickydee
One issue with a seat is that if you fall off because it tips forwards, you can just jump off forwards and end up standing on ground, holding handlebars low, below the level of your waist, with the rest of the segway behind you. So far so good.
Problem is, as this happens, the seat punches you in the back!
This maybe why regular Segway does not have a seat. Good example of why you have to eventually build something to find these sorts of things out.
Maybe I need a very well sprung long-travel telescopic seat mount.................
John
REMEMBER this is not a full fledged Segway with all it's back-up circuits, so it will not be as stable in rough conditions such as the woods or trail riding.
It is a fun project though and can give you hours of fun building, testing , and riding.
Thanks for the comment
Mickydee
If you are going to build this I would suggest you bite the bullet and buy the Sabertooth.
realy good
Sparkfun have just released an updated version of their 5dof analog output IMU.
IMU Analog Combo Board - 5 Degrees of Freedom IDG500/ADXL335
Part number SEN-11072
So, everything is OK again.
John
(It was the 45 degree braces and slotted motor mount holes that really caught my eye though. Hallmark of an Engineer. I will be keen to see your next instructable!)
GOOD NEWS EVERYONE
This clone IMU on eBay looks exactly like the SparkFun 5dof analog output IMU that they have now discontinued. Price is good too.
http://www.ebay.com/itm/190478609162?ssPageName=STRK:null:IT&_trksid=p3984.m1542.l2649
This may help a few people.
John
For anyone who wants to take the plunge and have a go with a 6dof Sparkfun DIGITAL IMu I have just attached some code to page 53 of my skateboard instructable. Not fully tested yet but all the values it gives seem smooth and about right.
http://www.instructables.com/id/edit/?instructableId=E3C1NR6G6MPQ5EM#instructableId=E3C1NR6G6MPQ5EM,stepId=SZGO7T3GZKE1JXL
John
I also have a wheelchair I got at a garage sale with very similar wheels and motors to yours and would like to construct a "Sitway". However, when I turn the wheels there's about 5 degrees of "slop" before they engage the motor/gearbox, and I'm thinking that there's no way it can maintain stability with that much slop. Do your wheels have that much slop?
Eric
Is an issue when balancing in one place. If you set the gain too high machine will start to oscillate as gyro detects the sudden jolt as gears move (backlash). Can still make it work OK but with lower gain the machine feels a bit "mushy" as you ride it. Can sometimes overcome problem by having low gain around +2 to -2 degrees of tilt for example, then increase the gain a little as tilt angle increases (and so after any backlash from any recent change in direction has been taken up by the gearbox) to tighten up the ride.
Best solution would be motor with a toothed belt drive to wheel. Working on something now but not as easy as it sounds.
I built this thing as a low cost project, and that is the reason for using the used wheelchair . If you want to get tighter balance you should use a chain drive system.
I have thought about repacking the gear box with heavy grease to smooth out the
gear lash. I plan to rebuild mine using a chain drive system and larger wheels.
This was my first attempt at building a "self balancing" vehicle, and am learning as I go. It's a fun project. Go for it. You wont be sorry
http://www.ebay.com/itm/24V-350W-Electric-Motor-W-Gear-9T-Sprocket-24-Volt-350-Watt-MY1016Z3-/180734270314?pt=Motorcycles_Parts_Accessories&hash=item2a149a1b6a&vxp=mtr
Part code number is MY1016Z3
Almost zero backlash in the reduction gears.
The chain sprocket keyway eventually works loose as not really designed to be going from forward to reverse all the time. In the end I took end plate off and welded the chain sprocket on using burst of MIG, then sprayed it with my anti-spatter spray to cool it, had a cup of coffee and left it for 30 min to cool, then another small burst and so on, to make sure I did not cook the outer bearing. Works fine now. This way you can use a bigger wheel without resorting to a massive chain sprocket on the wheel.
Go for it!!! you wont be sorry. Let me know if I can be of any help to you.
Your friend
Mickydee
It balances very well. I absolutely agree with letting the machine balance you. It actually helps on the skateboard to hold your legs rigid. Beginners do better on it than surfers who instinctively try to correct what it is doing.
Alternative to holding onto the stick would be to make a seat with a full chair back, like a racing car seat, to create the rigid object (i.e. the rider) then use a hand control to adjust the target balance point of the balance algorithm to make it go forward or back. Working on code for something like that now.
Also check this out - works on this principle:
http://www.youtube.com/watch?v=ik8RpV8w08M
Meanwhile, I have improved the code quite a lot on my skateboard page if you want to try out / modify the updated version.
Best wishes
John
I would love to use a hand joystick to control this thing. I have salvaged the controllers from two old wheel chairs that might be used for this purpose.
I will try your new code and see what happens
Mickydee
I have downloaded your code, modified it a little, including a version with faster turning rate and emailed it to you to try out.
I am working on a hand controller that controls froward/back speed as well as turning at the moment, so you do not actually have to lean to control it.
Will post code when all bugs sorted out.
Re Speed: People always ask how fast these things go. With self-balancers it is all about control, not speed. This could be made faster by simple code modifications, however, quite rightly, the machine at present is set up to be very gentle in its response to tilting. Whether you would want to go really fast is another matter though! It is a bit like the front set of a roller coaster - nothing in front of your face but the ground. Mickdee is correct, these machines are deliberately overpowered so they can respond very fast to angle changes and so certainly can cause injury if out of control. Small incremental code changes are the safest route to take as confidence builds + no loose wires.
Best wishes
John