**COMING SOON TO KICKSTARTER! Follow here: https://engineerdog.com/tinycnc/ **
2018HackadayPrize Final Video:
This project started when my imagination was set to wander by a sentence from the book Invent To Learn.
"Erector Set, Tinker Toys, Meccano, Lincoln Logs, LEGO ... All of these toys could be used to construct fanciful models of things, but not the things themselves. The game-changing 'toys' available to today's girls and boys are capable of making real things."
Of course that quote refers to things like 3d printers, laser engravers, and the like, but I saw it as an interesting challenge. A toy that can make real things... Why not customized coffee mugs? :)
TinyCNC PCB SPECS:
I found it necessary to make a customized PCB for this application. I could not find an off the shelf arduino based servo driver that did everything I wanted for the cost & size I needed. I ended up finding Scott Pierce's open source meped pcb designs & modifying them for my needs. This is the result:
- Utilities 1x Arduino Nano V3
- System Inputs: Up to 2X Analog Joysticks, Bluetooth (HC-06), Ultrasonic (HC-SR04), IR wireless remote
- System Outputs: Up to 9x servo motors, built in Buzzer & LED.
- Power Requirements: 6VDC Wall Wart or 4X AA (Energizer Ultimate Lithium Recommended)
- Drives servos directly from battery power unhindered by the arduino.
Mug-O-Matic Tool Path Summary:
1. Create or find an image file you want to draw and convert it to an STL. that is 0.1mm thick.
3. Use Processing to send commands line by line
What about the rest of the Tiny CNC Collection?
The 20mm spaced 4x screw hole pattern I've selected allows for easy reconfiguration of all modules at 90 deg angles.
All parts can be assembled
For all of these projects I drive the robots with an arduino nano, a custom expansion board, & 4x 1.5V batteries (Energizer Lithium Ultimate recomended).
The servos are also great because they don't require motor drivers and they are physically small. I chose MG-90S over their plastic-geared counterpart because I've broken too many plastic SG-90s. The metal geared servos have a ball bearing, are safely back driveable, more durable, and produce a little more torque. Up to ~0.5kg from the linear actuator in my simple experiment, though it varies directly with voltage.
My idea was to build off of another interesting opensource plotter robot design by MakerBlock. He and others developed arduino code that allowed a robot to read g-code and plot with a marker using hobby servos, a task typically done with stepper motors. Great idea and perfect for making an ultra low cost robot that still had lots of functionality.
The other part of the inspiration was to emulate the famous Egg-bot, except with lower barriers to entry, more hackability, and to produce objects with more everyday appeal.
I began this work with research and very rough sketches until I came up with a plausible model. I leveraged the proven arduino case design & electronic aspects from my own previous work on SimpleSumo robots to give me a boost.
A good portion of the technical work on this project is detailed 3D modelling. The gear profile and CAD files were designed with Fusion 360. All parts were printed in my basement on my Prussia I3 MK2S. I use eSun PLA+ material because it is super rigid, dimensionally stable, does not require print rafts, and is human/environmentally safe. That last bit is particularly important for objects that may be printed in classrooms.... Read more »