Hacking the Wheelchair

A project log for Hand Drive

A wheelchair attachment that allows any wheelchair to be powered in a rowing motion. It is 3D printable, open source, and available to all.

kate-reedKate Reed 08/14/2015 at 18:090 Comments

Hacking the Wheelchair

Starting off

We are beginning a studio making wheelchair accessories. We started off this studio by learning Autodesk Fusion, the software we will be using for this project. Fusion is a 3D modeling software that allows you to edit dimensions and sizes on models you make. We spent the first few days making objects in the software as exercises. I made a phone case.

Once we were done learning the software, we brainstormed as a studio group on what improvements a wheelchair needs and how we can hack it. We want to accessorize the wheelchair as apposed to redesign it. We broke up into groups and started to brainstorm more in-depth.

Our group decided on making the wheelchair faster. We live in a busy fast paced world that the wheelchair hasn’t necessarily kept up with. We want to use a ratchet mechanism, which would allow the user to wheel faster in the chair in a rowing motion as opposed to a wheeling motion, a similar motion to the arms on an elliptical machine. We are mainly focusing on the ratchet mechanism moving the wheelchair forward but hopefully if we have time we can work on brakes as well.


We started off the day with a lot of bike parts. We wanted to get the parts from the bike wheels to see if we could use them for our project. We took the wheels apart and explored, and found that we already had some mechanisms from parts that we could recycle instead of creating our own. We started making attachments that would make the parts usable for our particular situation. The tricky thing is that because of the parts that we have, the wheels can only turn one way so we have to use a slightly different system for each wheelchair wheel. The left and right wheels are flipped mechanically. We spent the day designing separate parts for each. We should be able to test them out on Tuesday once they have all printed out. Fingers crossed that it will work!

More Parts

Today we continued the process of making parts and testing them out. We put the main part of the right side together today, and it’s looking like it’s going to work well. We are just waiting to finish the design and print one more part to finish it off. Hopefully it will work and we can start on the left wheel tomorrow.

We have put the breaks part of our project on hold, and are just focusing on the speed right now. We are chugging along!

Design Change

Throughout the studio we have kept the project pretty simple design change-wise. We have pretty much kept the same design the entire way through, but today we made a design change.

After testing our previous spider attachment design we realized that we needed to beef it up because it was breaking when we applied force on it. We also realized that the way we were connecting the 8020 bar to the mechanism wasn’t helping our design. It was giving it too much torque, and adding stress to the entire mechanism. We took out the need for a right angle with the 8020 bars and redesigned the connector to accommodate the changes. We are printing out the final pieces tonight and tomorrow!


Today we had a realization. After we put one of the sides together we realized that we had made two of the same sides, but in different ways. We made two of the right side, although this was unplanned and would be considered a mistake, it turned out to be a good thing. We had come up with two completely different ways to do the same thing and through doing this we found that one way was much better.

Once we had wrapped our mind around making the left side of the system, it actually wasn’t that difficult. We had all the hard parts made, and just had to edit them a little to be able to use them for the left side. They are printing out over the weekend, and hopefully they will fit right into place on Monday. We are cutting it close!