Projects

Motorized Beach Wheelchair

A joystick-driven electric beach wheelchair on a PVC frame, built for under $1,500.

Avalon Beach Patrol, NJ Scientific Research (Adv), Westtown School
The finished motorized beach wheelchair in front of a brick wall: a white PVC frame with a navy cushioned seat and back, a joystick on the armrest, four wide gray balloon beach tires and a chain drive to the rear axle
The finished chair, with its PVC frame, balloon tires, chain-driven rear axle and armrest joystick.

For Westtown School's Scientific Research (Adv) course I built a motorized beach wheelchair. Avalon Beach Patrol in New Jersey provided a manual beach wheelchair as the starting point. The goal was a version the user can drive without a caregiver, for under $1,500.

Overview

I began with the manual chair from Avalon Beach Patrol. Its main limitation is that it is hard to move through sand, so the user depends on someone else to push. I set a budget of $1,500 and looked at materials that would hold up to sand and salt water.

Design

I modelled the whole chair in Fusion 360:

Four-view technical drawing of the wheelchair frame from Fusion 360: front, isometric, top and side views with dimensions in inches, including a 19.25 inch frame width, 23.45 inch track, 25 inch length and 17.75 inch seat height
Four-view drawing of the frame with dimensions, from the Fusion 360 model.

Build

The frame is PVC cut and assembled to the CAD dimensions, with marine-grade hardware and reinforced joints.

The wheelchair mid-build on a workshop bench: the PVC frame with seat cushion and joystick fitted, a silver electric motor and battery box mounted under the seat, one balloon tire attached, and a drill, chain and sprocket on the bench
The chair mid-build, with the motor, battery box and the first balloon tire on the PVC frame.

Electronics and control

Two waterproof electric motors drive the rear axle by chain, powered by 12 V 50 Ah LiFePO4 batteries. The user drives with a joystick on the armrest, and there are redundant emergency stops. The electronics sit in a waterproof enclosure, and the chair also has a seat belt and a water sensor.

Side view of the finished motorized beach wheelchair against a brick wall, showing the chain drive from the motor to the rear balloon tire, the battery box under the seat and the joystick on the right armrest
The finished chair from the drive side, showing the chain drive and the under-seat battery box.

Results

Compared with the manual chair, the motorized version gives the user control through the joystick, is more stable on sand, and has waterproof electrics. Six testers rated both chairs in a sand pit and in a lake.

9.0/10
maneuverability in testing, vs 2.0/10 for the manual chair
$1,500
build cost, vs $3,000+ for commercial motorized chairs

The new chair took 55.6% of the total rating points against 44.4% for the old one. The largest gains were in maneuverability (9.0 vs 2.0), stability and safety (8.0 vs 3.0) and speed control (9.0 vs 4.0). The old chair still scored higher on maintenance (8.0 vs 7.0) and durability (6.0 vs 5.0). At $1,500 the build cost about 50% less than commercial motorized beach wheelchairs, and it lets someone get onto the beach without a caregiver pushing.

Research poster

The poster for the course asked whether motorization and upgrades improve user independence on beach wheelchairs. It covers the methods, build procedure, test results, conclusion and future steps.

Research poster titled Can Motorization and Upgrades Improve User Independence on Beach Wheelchairs? by Kilan Rougeot, Westtown School Scientific Research (Adv), with sections for introduction, methods, build procedure, results bar chart, results analysis, conclusion, future steps, references and acknowledgments, plus photos of the manual chair, the motorized chair and the 3D model
The research poster, titled Can Motorization and Upgrades Improve User Independence on Beach Wheelchairs?
Full-size poster

What I learned

The project taught me Fusion 360 modelling and assembly drawings, electromechanical integration, material selection for sand and salt water, waterproofing, and building to a cost target. The testing also showed where the trade-offs went: the motorized chair gained most in maneuverability, stability and speed control, while the manual chair still scored higher on maintenance and durability, so those are the two things to improve next.

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