The Verdict is in…Kids LOVE SimpleSumo!


After months of development in my basement I’ve finally released the latest & greatest open source educational robot toy on the block, SimpleSumo!

Mini-Sumo is an established robot sport involving 2 autonomous robots trying to find and push each other out of a ring. A tame version of Battlebots.

SimpleSumo allows anyone to build their very own competition ready mini-sumo robot with no prior knowledge in robotics at a price that almost anyone can afford.

Intended for small groups ages 10+, this kit is can be enjoyed by beginners as well as advanced makers. SimpleSumo is designed with education in mind and is supported by free online resources including assembly instructions and video demos/lessons.

Beginners will find that building SimpleSumo robots offers an excellent breadth of exposure to STEM education concepts. Building robots is a multidisciplinary activity and involves Arduino coding, physics, introduction to mechanical & electrical engineering challenges, 3D printing, and principles of scientific thinking wrapped in a highly engaging hands-on package.

More advanced users will find these robots are easy to learn but hard to master. While some elements of the game rely on luck, much more has to do with player strategy and vehicle design.


That’s my marketing spiel anyway, getting here was quite a bit work!

This project was inspired in part by a company in Altanta that uses sumo robots to teach kids Arduino coding. I was intrigued as I watched their videos of kids enjoying the battle aspect of the robots, but it was clear to me that something was missing for them.

The kids were taping straws & construction paper to the robots or drawing shapes on them with a sharpie. They were dying to make it their own! 

I thought, wouldn’t it be cool if the mechanical customizations were as easy as a Mr. Potato-head? Something more like Lego Mindstorms but actually affordable and with a programming language worth learning like Arduino. BOOM great idea!

Initially I wasted too much time experimenting with 3D printing LEGOs, convinced that they were the key to the endless customization I envisioned. but eventually I determined that actually printing the bricks was too great a challenge. My top rated finely tuned FDM printer can print functional LEGOs, but only if they are used to mesh with mostly real LEGOs and not lots of other printed bricks.

The tolerances stack up and things get ugly if you stack too many printed bricks.  I finished that chapter with a cool collection of 3D printable Lego designs and the knowledge that trying to make SimpleSumo primarily a Lego toy was a terrible idea.


Life got a lot easier after I look LEGOs out of the equation.  In September I was finally able to bring the sumo ring out in public for the first time to MakerFaire PDX 2017. Kids loved it! For the whole weekend I watched them jumping half on the ring, pushing the robots into each other, smashing alternate parts into place, and screaming kill himmm!!

And the robots are fun. You can’t help but want to watch them search around, root for your bot, and reflexively reach out to save it when it looks like it will drive off the edge even though it won’t.

The robots survived the weekend with the help of a little super glue. Nothing like a kid or a 4ft drop to help you find the weak points in your design. Or one kid ripping every single wire out to help me ‘upgrade’ it 😊.  Afterwards I reinforced the models to perfection prior to release.




Everything is available now!

This page here is the SimpleSumo info hub that shows where everything is. Kits are available on my store, code is on Github, assembly instructions are on Instructables (Take a second and go vote for my project in the contests will you 😉) , 3d printable files are on Thingiverse.

This work was shared as open source with the intent to make it more accessible to the people who would benefit most from using it and to make it easier for other talented people contribute to the fun.

That means the code, 3d printable files, and shopping list are freely available to anyone that want it. (Although, I did reserve the cool expansion models for sale for a couple bucks to help recoup the R&D cost of this work.)

I had envisioned this toy being used in science classes, after school clubs, and the like. I would have loved to play with this when I was a kid. Heck I love playing with it now. Moving forward I’m enjoying working on a video series explaining some of the science behind optimizing the design.

One of the coolest things is how easy it is to make quick modifications to change your robot’s entire fighting strategy. Right now there are 34 unique interchangeable 3d printable robot parts (and counting…). I’ll leave this post off with some pictures of what this thing can do, enjoy!




Unrelated to SimpleSumo but this design is coming out this weekend too. While at makerfaire at the OMSI museum Vivian fell in love with the magnetic gear table. I couldn’t NOT make a set for our refrigerator. She loves it. She is my favorite. 😍

UPDATE: Refrigerator Magnet Gear Spinner linked here.




What do you think?

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.