Jared Lepora with his robot made from Lego Mindstorms parts
Nathan Lepora
A robotic arm built from Lego pieces by a 16-year-old and his father can grasp and move objects, demonstrating similar qualities to a dominant robotic arm.
Jared Lepora, a student at Bristol Grammar School, UK, began developing his arm when he was 14 years old with his father. Nathan Lepora who works at the University of Bristol.
The device borrows principles from the latest robotic hands, including the Pisa/IIT SoftHand, but uses only off-the-shelf parts from Lego Mindstorms, a line of educational kits for building programmable robots.
“My father is a professor of robotics at Bristol University and I really liked the designs [of robotic hands]” says Jared. “It just inspired me to do it in an educational format and with Lego.”
The hand is driven by two motors using tendons, and each of the four fingers has three joints. A differential made from Lego clutch gears connects the fingers so they move together until they touch an object and then stop moving, similar to how people grab objects.
In tests, the Lego hand successfully grasped nine household items, including a plastic cup and bowl, and a stuffed toy weighing 0.8 kilograms.
One finger on the hand can fully close in about 0.84 seconds and open in 0.97 seconds—about twice as fast as the 3D-printed Pisa/IIT SoftHand equivalent with metal bearings. In static tests, the Lego hand finger could support a load of 5 Newtons and push 6 Newtons of weight, and had a closing force of 1.8 Newtons, compared to 8 Newtons of load-bearing force, 7 Newtons of pushing force, and 2 Newtons of closing force for the 3D-printed version.
“You'll never get as good a hand [as a 3D-printed hand] in terms of what it can do with a Lego arm,” says Nathan. The Lego arm is also significantly larger, with each of the four digits measuring 145 millimeters long and 30 millimeters wide.
Lego Mindstorms was discontinued in 2022, but Jared says the device can still be upgraded with various Lego parts. “The way I implemented the motors makes it easy to remove them and add new ones,” he says.
Topics:
