Engineering · 2026
PressAble: an adjustable, shock-absorbing switch mount
A low-cost highly-adjustable upgrade for a school's existing gooseneck switch mounts: quick, fine adjustment from two ball joints, and a foam buffer that absorbs hits from any direction.
Close-ups, wheelchair to switch: rubber-lined clamp, ball-joint stack, foam clamp assembly, foam pad
Students at Park School communicate by pressing a switch with their head or elbow. Their gooseneck mounts spring back after bending, so the switch never quite lands where the therapist puts it, and it drifts after repeated hits. PressAble adds two ball joints that cancel the springback and set the angle, plus an omnidirectional foam buffer that absorbs a press from any direction.
- Role
- TeamTeam of 4 (Design Thinking & Communication). I lead design and prototyping, including the Fusion 360 CAD model, the printed parts and building the mount. My teammates led user research and documentation.
- Duration
- Spring quarter 2026
- Tools
- fusion-360, fdm-3d-printing, heat-set-inserts
- Skills
- human-centered-design, user-testing, prototyping, design-for-repair, design-for-production
Goal & constraints
- Two priorities: durability and usability.
- Durability: build from off-the-shelf parts the school can replace or reprint, rather than one expensive, highly engineered device that's hard to fix when something breaks.
- Usability: it had to beat the mount they already had, or there was no point building it.
- Hold the switch within a few millimeters of a cheek, chin or head, adjustable without tools in seconds
- $150 prototype budget; no sharp edges for kids as young as 3; no added wheelchair width.
Process
- Watched students use their current mounts and interviewed the school's occupational therapists. This is where we discovered the "last inch issue." A gooseneck, like any bend-to-shape arm, always has a degree of bounce back, thus causing the switch to always end up just out of reach, or in reach but at the wrong angle, so the therapist bends harder and tries again while the student has no way to communicate.
- We looked to an industry that had already figured out precise point-arm adjusting mechanisms: photography. This is how we discovered the ball socket parts that powered our design.
- The joint at the gooseneck repositions the pad anywhere within its radius with no springback, then locks with a thumbscrew. It replaced our first idea, a linear extension mechanism, while offering even greater degrees of freedom. The joint at the pad gets a rubber disc inside, so it stays slightly loose and adjusts with firm finger pressure instead of a thumb screw
- We originally planned for the use of a complex spring-plunger assembly but when impact testing, noticed that the direction of force had to be almost completely parallel to observe the compression behavior. The answer was simple: a cheap piece of foam could bend, stretch, and squish in any direction while still supporting a button mounted to its end.
- Left a mockup at the school for a few days. The therapists asked for softer foam, and the glued foam had stiffened. So the final pad pinches the foam between printed rings with heat-set inserts, with no glue.
- Lined the clamp jaws with rubber pads so it stops sliding on painted tubing, and handed off the parts list and STL files so the school can rebuild any part itself.
Result
0 mm platform movement in a 60-second tapping test, final design about $36 in parts per mount
What I’d change
Swap the screw-on clamp for a quick-release one, so moving the mount between chairs is faster, and cut down the number of screws in the foam pad assembly.
Printing this page gives a one-to-two page PDF.