With a large enough lever you can move the world. What can you move with the right mechanical advantage?

Hackaday's 3D Printed Gears, Pulleys, and Cams contest challenges you to show us some interesting motion by 3D printing a mechanism that uses... you guessed it... gears, pulleys, cams, or any combination of the three

Show us something delightful, impressive, and describe how it was done, and you can score one of our prizes. The top three entries will each get $275 cash prizes, and at least 7 runners-up will be awarded $100 credits at Tindie.

You! (Yes, you.)

We're going to show you a bunch of really incredible examples -- but don't be intimidated. If this is the first time you've printed two gears that fit together, we still want to see that as an entry! The path to great skill is paved with simple proofs of concept where you learn a lot. Let's celebrate each of those accomplishments together.


Some Inspiration to Get You Started:

Of course there are many many ways to put gears to work. This hummingbird is a great example of an automaton by Greg Zumwalt. He has a ton of examples of gear work on his Thingiverse page.

Are your gears the product of careful ratio calculations, or did you just eye it up? Either way, those are the kinds of details we'll be looking for in your entry.

Bijuo's hairless cat robot uses pulleys to map motion from the servos mounted on the body, down to the legs themselves. It's a really interesting take on locomotion. Of course there are a lot of other really great applications for pulleys, like building a string plotter, but we would also love to see some heavy lifting with a block and tackle if you're up to the design challenge!

This device uses cams -- basically an off center part of a rotating shaft -- to move a laser pointer in just the right way to draw shapes on a projected surface. The image here is one of Evan Stanford's designs that projects a star when you cranked. A clever design will let you make any shape you wish. Cams are also a wonderful way to lend motion to an automaton.


  • Three top entries will each receive a $275 cash prize
  • Seven runners-up will be rewarded with a $100 Tindie Credit!

How to Enter

Show pictures of your creation and tell the story of how you designed and built it by documenting it as a new project on Hackaday.io. Once you have published your project, look in the left sidebar for the "Submit project to..." menu in order to enter it in the 3D Printed Gears, Pulleys, and Cams Contest:

Judging Criteria

Beauty is in the eye of the beholder. That said, here are some criteria judges will have in mind while reviewing entries:

  • Motion: Does it move and is it visually interesting?
  • Design: Is it a new or novel design involving 3D printing?
  • Functionality: How well does it work?
  • Quality: Does it have impressive fit and finish?
  • Backstory: Was the design process explained?

3D Printed Gears, Pulleys, and Cams Contest Rules:

  • Contest runs 8AM PST Wednesday, January 16th, 2019 through 12PM PST Tuesday, February 19th, 2019 (here is a handy count down timer).
  • Sharing design files, schematics, and/or source code is highly encouraged (but not required). These will be considered during judging and are a big part of "backstory" and helping us understand your creation.
  • Existing projects, or projects that were entered...
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