UC Engineering Students Design Safer Weightlifting System

Weightlifting is an integral part of many people’s fitness. But lifting weight can also cause injuries, sometimes sending lifters to the emergency room. Three students at the University of Cincinnati set out to solve this problem through their senior design capstone project.

Blake Beard (electrical engineering), Phil Fedor (computer engineering) and Cameron Haynes (electrical engineering) all spent their last year at UC's College of Engineering and Applied Science designing and building a weightlifting system and smartphone app called Weightless. As lifters themselves, they saw a need for a safer way to bench press and lift weights.

“Safety in free weights can be a big problem,” Beard said. “If you’re bench pressing too much weight without have a spotter, you can run into some dangerous situations.”

Their solution was to create a weightless gym with safety features to prevent injuries caused by dropping or mishandling equipment. The team also wanted to make a system compatible with a smartphone. After some debate, they settled on a design that connects a standard weightlifting bar to a motor.

In their prototype, the weightlifting bar attaches via rope to a motorized device, which plugs directly into the wall. A sensor is placed on the rope to read the tension between the bar and motor. Users can use a smartphone app to set the weight they want to lift. The app communicates via WiFi to a Raspberry Pi (or microprocessor), which then communicates to the motor, increasing the motor's output to match the resistance the sensor on the rope reads.

Should there be a sudden shift in tension – for example, a drop – the Raspberry Pi detects this and can automatically shut off the motor, eliminating any potential for injury.

Since all the teammates have computer and electrical backgrounds, working with the motor was the biggest challenge of the project. Thankfully, the team could collaborate with several mechanical engineering students to work through some difficulties.

Though the team hopes to develop Weightless into a full-scale model, Beard and his teammates were satisfied with creating a proof of concept. So far, the prototype can regulate 20 to 40 pounds of resistance. Should they want to create a full-scale design, they will need a new motor with more power that can pull larger weights.

Most importantly, this design succeeds in addressing the problem of weightlifting injuries, increasing weight without spotters while decreasing the potential for injuries. If Weightless hits the market, lifters everywhere can breathe a sigh of relief next time they hit the gym.