Tim Giles Builds a 3D Printed Robotic Third Hand

Tim Giles is a maker and engineer who lives in Rochester, New York, and he’s created a series of instructions and some code to help you 3D print and build a Robotic Third Hand to make you the Terminator of benchtop electronics work.

Giles’ Robotic 3rd Hand is worn on the forearm to deliver a tool that it holds straight into your waiting fingers on command. His device uses some 3D printed parts and uses a Pro Trinket as its brain. It’s a servo-actuated tool holder which uses its Pro Trinket to wait for you to press a button which then extends a screwdriver into an easy-to-grab position.

Giles made this seriously cool device for the Hackaday Everyday Carry Contest (he was one of the winners!) and you can get all the necessary files and instructions at Hackaday.io.

According to Giles, once you’ve assembled the 3D printed parts with a series of screws to securely hold the screwdriver tray, the arm that actuates the screwdriver tray can move freely. He used his UP! Mini to print the parts.

All the design files can be found on Thingiverse.

He says the entire project took five revisions for the mechanical parts to assure that the device fits curvature of his forearm ergonomically. One of the wings includes a recess to hold the battery, the other wing has a recess that holds a 5V boost supply.

The device uses a common, snap action SMT button that he pulled from a junked VCR. It’s held within a 3D printed holder and affixed to the hand with a rubber band.

“I am very happy with how this all works,” Giles says. “I’d like to add the flashlight functionality and an area to hold several of the screwdriver bits.”

He’s also pleased with the way the 3D printed parts worked as he constructed them.

“My printer is an UP! Mini – which I think is a fantastic printer – but it only has a roughly 4″ print bed, and this contraption was a little more than 5″ long. Having it be 3 separate sections also made the design a little easier,” Giles says. “I’m doing all the 3D modeling in Design Spark Mechanical and I’m learning a lot along the way. Before this project I only ever used design spark to make really simple parts, but this project is forcing me to learn how to use it well.”

What do you think of Tim Giles’ Robotic Third Hand? Would this make it easier for you to take on electronics work? Let us know in the Robotic Third Hand forum thread on 3DPB.com. Check out videos of the third hand in action, as well as some more photos, below.