TTU Mechanical Engineering Students Design and Build Walker
It’s enough of a challenge for a toddler to learn how to walk, and it’s an even bigger challenge when he’s completely blind. That’s what 2-year-old Christian Buchanan faces; blind since birth, Christian has been on track developmentally, but lacks confidence in walking. A traditional walker isn’t a good fit, since he doesn’t need the ambulatory help, and a conventional white cane isn’t the right solution either.
That’s where Tennessee Tech’s Early Intervention and Mechanical Engineering program comes into play. Student teams are presented with several challenges for special-needs children, all of which can be solved by designing and building adaptive devices. This particular undertaking had Austin Cook, Jarrett Snyder and Caleb Wilson partnered.
“It was Dynamic Machinery class with Dr. Canfield,” said Cook, “and the projects are a part of the class, for a grade. We’re given a sheet at the beginning of the semester of families with special needs children, or general special-needs projects, and we then pick from that sheet.
“We then met with the family and got to meet Christian. He needs something that can help him maneuver his way around in the house and elsewhere, and something that’s light enough to be easy to transport.”
Early designs for the walker were all similar, with a stable tripod-style base that wouldn’t be easy to tip over, casters for mobility, an upright tube and a handlebar-style grip. The design then evolved into a simpler form, with the tubing cut from carbon fiber stock for strength and light weight. The upright tube then incorporated a telescoping section secured by a clamp, giving a range of adjustment from 18” to 35” as the child grows.
“When we were in the design phase, we were trying to come up with a really simple, minimal design that would hold together, especially compared to what the family originally had, which was a big folding metal contraption that had to weigh 10 pounds or more,” said Cook. “We figured out that carbon fiber is one of the strongest, lightest materials we could use, and found a vendor that sold the tubing stock as well as the clamp for the telescoping upright shaft.”
The walker’s tripod legs were fitted with furniture-style casters, and the four-way joint that holds the legs and upright together was fabricated out of aluminum and custom-welded in the shop. The entire assembly was then painstakingly tested for strength and stability, with Loctite adhesive bonding all the parts together. The final product weighed in at only 2.2 pounds and came in at under $275 total cost.
“It’s not a complicated design, it’s really pretty simple,” noted Snyder. “What we found out, though, after talking to Vanderbilt and other places, was that there isn’t a walker available that meets this particular need. Our first idea was to take something that’s already out there and modify it to fit, but there just wasn’t anything; that left us to start with square one.”
As with any innovation, the final proof lies in how well it actually works in the real world. Christian’s mother Lacey tells the story in an email to Caleb Wilson:
How are you doing? I wanted to let you know that since Christian got his walker that you guys built, his walking has improved so so much! He is now walking independently for 8 to 10 steps at a time, no walker, no support at all! His physical therapist is so impressed with his progress!!! The walker is so wonderful and SUCH an amazing piece of equipment for us! When Christian gets done with his walker, we are going to donate it to Special Kids, Inc. in Murfreesboro, Tennessee, that does rehabilitative therapies for kids with special needs like Christian, so that other kids can benefit from this awesome walker!!!!!
Thank you so much for the gift you gave us of helping Christian reach his potential!!! :)
She goes on to say:
The reason I am writing you is because I have a friend who has a little boy who has some developmental delays like Christian. Ryan is one day younger than Christian, he does not walk or talk yet, but he is not blind. His parents are not really sure just yet exactly why Ryan has delays. They are here this week visiting from Texas, and I was telling them about this amazing walker we have and how much it helped Christian. They let Ryan use Christian's walker, and Ryan took several steps with it on his first try!!!! They were so thrilled! I am writing you to see what it would take to get another walker made like Christian's, that we could send to Ryan in Texas. We would be happy to pay you for parts and your time if you would be able to make another one. In fact, I think you guys should patent your invention and start making them for kids with special needs! (you could call it the Christian walker hee hee). I know it's a fairly simple design, but is just works!!!!
In addition, the carbon-fiber tubing vendor, Rock West Composites, sent a glowing email to the team and extended them a full credit for the cost of materials on the next walker that they build.
“Christian’s physical therapist noted that he’s made a lot of progress just with the help of this walker,” said Cook. “He’s able to take 87 steps at a time, compared to 10 or 12 steps before. He knows where his room is and can get around the house with no problems, and is probably pretty close to being able to get around without the walker, at least indoors.”
It’s hard to think of a better example of the Renaissance Engineer’s mission of being able to solve societal problems through innovation, creative thinking and technical skills.