Mug-O-Matic: A Modular Tiny CNC Drawing Robot


Hello everyone, I’m sorry to disappoint but after careful consideration I have decided to shelve this project. 😦

The Mug-O-Matic was a very promising toy but overall it didn’t live up to my expectations. Sure it was able to draw some neat stuff, but doing so reliably was a challenge and that last thing I want is to put confusing/frustrating technology in kid’s hands.

The small hobby servos I designed this entire project around were inexpensive & easy to buy/use, but they severely limited the drawing resolution & positional repeatability of the robots…which matters a lot to a plotter! The general robotic controls & reconfigurable aspects worked great, but its primary purpose of being a plotter was too compromised to ignore.

Of course I could redesign everything to use standard stepper motors & controls to achieve a super high drawing resolution. But doing so would greatly increase cost & complexity and I wanted the bot to be a simple plug & play toy. I’m also not sure how much additional cost would be justified to get that novelty value out of a mug drawing bot. IMO if I produce & sell it in this form then it has to be cheap because there are so many good STEM education robot alternatives out there for me to provide a competitive offer in a higher price bracket. In any case, real commercial mug customization is done with printers, lasers, or decals anyway…not plotters silly! If I jammed sophisticated controls on it then I’d also want/need to change the entire architecture of the machine & code. So in a sense, the current design is totaled.

If you are still interested in picking up the PCB for your own use anyway, I encourage you to check out the MePED PCB by Scott P. at this link here.  This is the predecessor for the TinyCNC PCB and does most of the same stuff and has the same mounting dimensions.

If you are curious to see what I’m tinkering with next you are welcome to follow this blog and check out my brand new web store here:

The rest of this page will be preserved in case anyone finds it useful.





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The TinyCNC collection are a one of a kind educational maker toys!

Mug-O-Matic is a 3-axis drawing robot that can customize coffee mugs! This capable little robot can draw anything you want via manual control, bluetooth, calculated algorithms, or even g-code. So you can enjoy your custom mug creation, then wipe it clean. You could make it totally different every day for a year, and not make the same thing twice!

Its little buddy, the Desktop Sentry is a pan-tilt turret that guards your desk! Also controlled via joystick, bluetooth, algorithms, or g-code, this device can automatically guard your space with a laser or a rubber band launcher or be used for light writing.

The intent of the project is to produce a fun and accessible educational tool. One that encourages people to engage in tinkering and making things because those activities are powerful ways to learn.

To best serve that purpose these robots are designed with hackable open source hardware and are controlled by free open source software. Building this bot offers an opportunity to experiment with 3D printing of software such as Processing, Repetier Host, Slic3r, and of course Arduino – the most common and universally applicable microcontroller for physical computing. Knowledge gained playing with this toy is transferable to many other real life applications!

The kits offered are self sufficient and contain all the hardware & tools necessary. No soldering or bread-boarding is required, controls are plug-&-play. And like all projects it is well supported with online instructions & videos.

These are real tiny CNC tools in a fun size package that allow you to make your own custom creations! What will you make?

Interested to get your hands on one? Let us know, your support is valued!


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To keep my offering simple, I’ve separated this section out a bit.  Much like transformers, there is a lot more than meets the eye to these little bots… 🙂

This open source project was a finalist in the 2018 HackaDay Prize, so you can read all about its development history here.

From my research into the highly recommended book Invent to Learn​, kids learn by doing and are most engaged when they are able to independently experiment rather than just being told what to do. To that end, all components are modular so the parts can be rearranged to build lots of different things to facilitate experimentation!

The Mug-O-Matic is actually just one possible configuration from the Tiny CNC Collection. This means inspired students can mix, match, and build their own custom real robots!





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License & License Intent:

-The assembled Mug-O-Matic & the Desktop Sentry toy robots will be for sale and I do not want to create competition over sales for my own body of work. You may use the files to build a complete Mug-O-Matic for yourself or your classroom, but please do not sell them. Please note that completion of this device requires a TinyCNC PCB.

-The software, PCB design, and 3d models of sub-assembly modules & individual components (linear actuator, pivot joint, brackets, etc) are free for you to use however you wish! Source files are provided!


Instructions, & Support:

Required Software Download Links:

Image Preparation Links:

Where to Get Parts:

Recommended Reading Material: 

You don’t have to buy any books to learn arduino. There are lots of free resources & videos online and code examples built into the arduino IDE. But if you learn best with a book in hand then these are the go to’s:


Links to Models