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Super-Cheap and Effective Off Road Wheelchair Hack

Last year for Alchemy, we decided to launch a really ambitious art project on a really short timeline. It almost didn't get done, but we were able to get it out just in time... and it worked!

Ferris, Abigail, and Robin playing with the
bubble generator
Our project was to build a different kind of art car. Alan got the idea to build an Off Road Wheelchair for our friend Robin, who is an anthropologist and a disability advocate, so that she could get around these outdoor festivals to enjoy all of the crazy awesome stuff that happens there. We did the first round of fundraising at the Alchemy Art Fundraiser (FB event link here) and afterwards Alan, Joy, and Robin set up a second fundraiser at Freeside. Once they raised the money (which still had us on a razor-thin budget), I picked up the project from there and managed the planning and build. As it turned out, I was in way over my head.

The idea was this - Robin had a really hard time getting around at these events and spent most of her time at her camp. She has partial paralysis on her right side, making it really difficult for her to get around, especially on uneven terrain.  There's sooo much to see there, so we wanted to help her out. But we didn't just want to help her get around, we wanted make her the most intimidating and crazy-powerful vehicle out there so that nothing would stand in her way! It was our way of making a statement and drawing attention to the idea that Radical Inclusion means that not only should everyone be welcome, but everyone should be able to join in. The way we saw it, if we had the ability to make that happen, then we should.

A rugged, human-powered wheelchair can cost between $2,500 and $8,000. An electric or gas-powered wheelchair can cost upwards of $10,000. Our chair had to take steep inclines (including "effigy hill") and rough terrain on its own power, run reliably for 3-4 day events with spotty access to infrastructure, and have similar accessibility, controls, and behavior to a normal wheelchair.

This was a huge dilemma, which we discussed in detail in our first blog post on the project. The only reasonable solution for our budget was to modify a high-torque zero-turn lawn mower to turn it into a super-powerful, ruggedized wheelchair. It's not ideal, but it's a surprisingly effective solution... especially with a 2 month, $2,300 project.

Humble beginnings for a crazily ambitious project.
So we found a crap zero-turn mower and bought it without the deck for $1,400. It was ugly, had structural damage, electrical problems, body damage, rust, no lights, and was really heavy. However, it also has a 20HP motor and working hydrostatic transmissions that distribute huge amounts of torque to the off road tires independently, meaning that the machine can pivot in place similarly to a regular wheelchair. It was a substance-over-style decision.

After that was a massive series of builds. We had over 30 people work on the project on and off. As the project wore on, we hit bottlenecks and people lost enthusiasm. There were a lot of challenges.

We had a huge number of things to get done to get the project ready. We needed to repair mechanical damage, do some structural welding, remove rust, reduce noise, repair the electrical system, add running lights, and give it style. We added a trailer hitch as well, but couldn't get the right kind of winch to attach to it in time. We'll have to take care of that on the next round.

Kate was one of the leaders on the project and did a lot of
mechanical work, as well as getting the new seat done.
Even with as many people as we had working on it, the project took every bit of the 2 months that we were allotted, including an almost sleepless 72-hour burn to wrap things up at the end.

Safety was the major concern. Everything we did was weighed, checked, and re-checked. We wanted to push the limits of the system, but we wanted to guarantee Robin's safety in the process. So we developed a testing program for the machine and a training program for operators. We watched some safety videos from zero-turn manufacturers together and built a training course behind the shop to practice circles, reverse circles, figure-eights, reverse figure-eights, and 5- 10- and 15-degree inclines from all angles of approach. It was a full day of work even after all of the planning we did.

Originally, Albert from Carbon Age Designs had designed a front clip to attach to the chair to reduce the likelihood of the chair tipping forward. However, we decided that the attachment could bottom our and cause the chair to roll forward, so it was too dangerous to use. Instead, we opted to include an inclinometer on the chair and train Robin on how to use it to keep the chair under 15 degrees for the initial test run. We have time to refine it later.

Igor and Smitty's last minute work to get the project ready
For style we looked to Ferris, one of the Directors at Freeside, who came up with the idea of setting up LED strips on the chair that robin could remote-control. He hacked together a battery power and IR receiver system for it that would be waterproof and set it up. He also added a bubble generator on it so that it will leave a trail of bubbles wherever it goes. We'll try blacklight bubbles on the next iteration.

Finally the day(s) of reckoning came and surprisingly... everything went better than expected! It worked the entire 4 days, though we did have to change the battery out at the end. It worked exactly the way we wanted it to and Robin even got to see the effigy burn up close for the first time. In fact, there was no camp at the event that she wasn't able to make it to including Area 51.

Of course, I wasn't totally satisfied. It was too noisy and I had really high expectations of the final result. The hacker in me wanted to build it from scratch, but the project manager in me was pretty satisfied with the short turnaround and low budget. We've got plenty of time to make it quieter, prettier, and more sleek. In the mean time, it gets the job done really effectively. When it comes down to it, that's really all the project was about in the first place.

Special thanks to Robin for her support and patience, and everyone that put your hard work into this project! We're going to keep developing it for this year's burns and push this idea as far as we can to develop a cost-effective, safe, and outrageous powered off road wheelchair.

Robin, looking stunning on her chariot of torque and ready to rock on any terrain.


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