[Ivan Miranda] isn’t afraid to dream big, and hopes to soon build a 3D printed giant robot he can ride around on. As the first step towards that goal, he’s built a giant printed hand big enough to hold a basketball.
The hand has fingers with several jointed segments, inspired by those wooden hand models sold as home decor at IKEA. The fingers are controlled via a toothed belt system, with two beefy 11 kg servos responsible for flexing each individual finger joint. A third 25 kg servo flexes the finger as a whole. [Ivan] does a good job of hiding the mechanics and wiring inside the structure of the hand itself, making an attractive robot appendage.
As with many such projects, control is where things get actually difficult. It’s one thing to make a robot hand flex its fingers in and out, and another thing to make it move in a useful, coordinated fashion. Regardless, [Ivan] is able to have the hand grip various objects, in part due to the usefulness of the hand’s opposable thumb. Future plans involve adding positional feedback to improve the finesse of the control system.
Building a good robot hand is no mean feat, and it remains one of the challenges behind building capable humanoid robots. Video after the break.
Continue reading “Big 3D Printed Hand Uses Big Servos, Naturally”




The robot face is introduced to us with a soundtrack befitting Stranger Things, or maybe Luke Million. The build was inspired by The Doorman, a creepy art piece with animatronic eyes. [Jens’] build started with a 3D model of a 3D mask, with the eyes and mouth modified to have rectangular cutouts for LED displays. The displays are run by a Raspberry Pi Pico, which generates a variety of eye and mouth animations. It uses a camera for face tracking, so the robot’s evil eyes seem to follow the viewer as they move around. In good form, the face has a simple switch—from good to evil, happy to angry. Or, as [Jens] designates the modes: “Fren” and “Not Fren.”


