[Matt Turner] tipped us off back in January about his homemade Segway project. Unfortunately that message slipped through the cracks but we’re glad he sent in a reminder after reading Friday’s feature an a different 2-wheeled balancer.
We like it that he refers to this project as being on the budget of a graduate student with a young family. We certainly understand where he’s coming from, and we hope he can ride this to job interviews to show them he truly lives engineering. The control circuitry is a bit higher-end than we’re used to seeing. He chose a Cypress CY8C29466 SoC to control the device. But the sensors are a common choice, using the Wii Motion Plus and Wii Nunchuk for the gyroscope and accelerometer they contain. This is a no-brainer since the sensors are high-quality, cheap and available locally, and communicate of the standard I2C protocol.
When looking for motors [Matt] was happy to find an old electric wheelchair on Craig’s List. This also gave him a gear box, wheels, and tires. He added a pair of motor drivers, with his own alterations to suppress feedback. Sounds like they run a little hot because he plans to add cooling fans to them in the future. But this first iteration is up and running quite well as you can see in the clip after the break.
[youtube=http://www.youtube.com/watch?v=rAZrFdnam3I&w=470]
Well… not sure if I want to ride something called “SegFault”. Nice work though!
Dear all old people.
It’s not Craig’s List. Its craigslist.
Just like its not Face Book. And its not “an internet web site”, its just “a website”.
That is all.
-Taylor
I would like to change the rim to make it look more eye pleasing.
Good job man, quite a healthy guy on the homemade segway and working perfect. Great !
OK! Great build! This is neat stuff, and very cool.
But… (of course I have a but…) is it really a good tradeoff to have it balance on two wheels and have all the complexity of gyros and reverse gear? I would personally prefer to have two small wheels trailing and use the extra internal space for another battery. I do realize that it then stops being a Segway clone and becomes a simple electric scooter mod, but wouldn’t it be simpler, longer range, and wouldn’t need power to stand upright? Just sayin’.
If only I’d grown up across the street from somebody smart enough to come up with something like this…. I’d be a millionaire by now.
Nice build, but this is not the first “Segfault.” The original is also a segway clone, but it is completely analog:
http://www.etotheipiplusone.net/?page_id=566
Thanks for the post, Hack a Day! Thanks for the kind comments, everyone—I am kind of surprised that no one’s mocked my PVC handlebars :).
Ivan – Until I got the control loop working well, I wasn’t sure if I wanted to ride it, either.
Trisha – I’ve been planning on adding new wheels (bigger and better looking), but just haven’t gotten around to it yet.
mikelinpa – The balance hardware takes up very little space. I do have room for another battery as is, but I don’t know that I need the extra range. (I haven’t tested it yet, but I’ve estimated the range as ~5 miles, based on the specs of the sacrificial wheelchair.) I’ll have to think about this more, but I don’t think that much power is required to stand upright, and I’m pretty sure that the way the motors are driven inherently results in regenerative charging. I think the two-wheel balancing form is actually more stable than a four-wheel system with such a short wheelbase, and it’s definitely a lot cooler and was a more interesting and productive challenge to build.
Jared – You can probably blame your lack of millionaire status on something like being shafted in a LEGO building contest because your submission was obviously too good for a 7-year-old to have made himself. 🙂
Ben – I’ve seen this other Segfault of which you speak, and I was bordering on distraught when someone else had the name on Hack a Day first. Though his was up and working first, it appears that my blog post announcing the idea and name predates his blog post announcing the same by exactly 3 months. 🙂 I have to give him mad props for such a nice product, though, as well as for actual build logs and completing his project much faster.
no need for the TVS diodes, install lower inductance capacitors on those H bridges.
figure 100uF per amp of motor current, and if the motors are run pwm the whole time then the capacitor’s ripple current rating should equal the motor’s average current draw.