The Thanos “Servos” Are Finally Printed 🤖

A small milestone, but an exciting one—the Thanos “Servos” for my smart robotic hand are finally printed!

When I designed the hand, I chose 1 mm wall thickness to keep the fingers lightweight and 1 cm spacing between the fingers so they could move freely without colliding.

The design looked great on screen.

Then came the first print.

Most of the parts turned out beautifully, but once I started assembling them, I realized some of the moving joints were too tight. That’s the difference between spacing and tolerance.

The 1 cm spacing controls how the fingers move relative to each other, but every sliding rail, pin, and hinge also needs enough clearance to account for the realities of resin printing. Sometimes, 0.1 mm is all it takes to turn a smooth joint into a stuck one.

So it was back to CAD.

I increased the clearances, adjusted a few mating features, and removed many of the support posts by reorienting the parts for printing. Less support means cleaner surfaces, less sanding, and fewer marks on functional areas, which can make assembly much easier.

It’s a small design change, but it saves a lot of post-processing. 😁

That’s what I love about engineering. Every prototype teaches you something, every revision makes the design a little better, and every print gets me one step closer to a robotic hand that actually works, and not just one that looks good on a screen.

Next up: time to assemble the fingers. 🤞🤖