How We Built A 3D Printed Rube Goldberg Machine

Formlabs
5 min readJul 8, 2015

“A Rube Goldberg machine is a contraption, invention, device or apparatus that is deliberately over-engineered or overdone to perform a very simple task in a very complicated fashion, usually including a chain reaction.”

Source: Wikipedia

How many engineers does it take to over-engineer a Rube Goldberg machine? As a hardware company — we make desktop 3D printers — we had quite the team, to say the least. To celebrate the launch of our latest resin, Tough, we gathered a toolkit of engineers to help build a 3D printed Rube Goldberg machine.

See Tough Resin in action with our 3D printed Rube Goldberg machine

Inspired by the Japanese children’s series Pitagora Suichi, we wanted the machine to be fun, surprising, and also showcase the properties of Tough Resin: durability, strength, and impact-resistance.

Here’s a quick peek at what our workspace looked like over the last few weeks:

Hot glue, hacks, and 3D printing

The See-Saw

Engineer: Ava Chen

Laser-cut platform for see-saw. Resin bottle as pivot. And, we’re off!

Spot the 3D printed snail that starts the ball rolling.

The Gears

Engineer: Matt Keeter

Copper tape on the pipe closed the circuit that powered the gears.

“I designed a generic gear in Antimony, my homebrew open-source CAD package, then used the template to make gears of different shapes and sizes.

I was very happy with our strategy for closing the circuit: we put copper tape on the pipe, then relied on the (conductive) ball to close a circuit and start the gears turning.”

Here’s a screenshot of Antimony, showing the graph on the left and the output on the right.

…and here’s a close-up on the graph representation.

The Hammers

Engineers: Gagandeep Singh and Sven Werhmann

“It was incredibly hard to develop a system to allow the hammers to fire with the small weight and size of the steel ball. We were able to do some calculations and use some free body diagrams to find the optimal pivot point for the hammers.”

We had to test multiple runs of the hammer swing which led to multiple smashed wine glasses. 8)

The Power Drill

Engineers: Hugh Medal and Dmitri Megretski

“Having many of the parts printed in Tough Resin really made the difference, allowing the drill-rig to keep trucking through multiple trial runs.”

The Drill Mount’s base

“I knew I wanted something with a bit of old-fashioned cast-iron machinery flair, so I offset the faces on the cradles to make a decorative raised area. I also modeled the holes for the clamp screws slightly undersized, in order to drill them to final size and tap them to receive screws.”

Support arm for the track that held up the dril.

“I needed something strong enough to hold up the entire drill, and not break under the twisting forces while driving the screws.”

Battery Connector

“This simple part is a great demonstration of how 3D printing can make life easier. I needed something to hold wires onto the cordless drill battery, but, like all cordless tool batteries, it was a weird non-standard shape.

I took a few measurements and modeled the part within minutes. I was then able to print it out in under an hour using draft mode.”

The Chain + Sprocket Combo

Engineers: Darian Zigante and Valentin Trimaille

The chain, printed in Tough Resin, is intended to show the mechanical wear properties of tough.

“The most exciting part in the entire making-of had to be when the chain and sprocket lifted the build platform for the first time. Seeing an entirely printed mechanical system, full of moving parts, on that scale, was very cool to watch.”

The chain model laid out in PreForm ready to be printed.

The Spoons + Elevator + Plinko Combo

Engineer: Adam Lebovitz

Here we go!

I wanted to show how shatter/fracture-resistant this resin is as compared to our Standard Resin. I also wanted the demonstration to be visually interesting. To keep the theme and continuity of the rolling steel ball going, I decided the ball should be what causes the pieces to flex.”

Sneakily positioned magnets helped trigger the plinko station.

The Finale

Engineers: Clark Anthony and Meg Maupin

A magnet cannon propels a 3D printed ball through a loop-de-loop.

“Our station uses magnetic force to propel a 3D printed ball through a loop-de-loop made of PVC pipe. The ball drops at the end of the pipe, hitting the mousetrap and setting off the confetti cannon.”

“The biggest, but most fun, challenge, was picking up all the confetti during the shoot. :)”

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