An idea for a rough and inaccurate yet fun and easy DIY CNC router.
For cutting sheets of polystyrene and other very soft materials.
In stead of a cutting piece spinning on a high rpm spindle, mounted to a sturdy frame, moved by very precise stepper motors which are controlled by computer, via an expensive stepper motor controller.
This setup would have a cutting piece spinning in a cordless dremel. (motion in the Z axis is yet to be though up), mounted to a radio controlled vehicle wich can rotate on the spot (e.g. rc tank or tumbler style vehicle.), which is controlled by a computer via a hacked transmitter. An infrared led attached to the top of the vehicle is tracked by a Wii remote which is connected to the computer via Bluetooth. The computer knows the position of the cutting piece by the data from the Wii remote, and thus can control the vehicle carrying the cutting piece with some accuracy and follow a specific path. (e.g. a 2d design of a part on the computer).
Software similar to http://www.smoothboard.let/wiimotewhiteboard/
can be used to find the position of the infrared led.
Software for controlling the transmitter is yet to be found. though I have seen computer controlled rc cars before. I myself have no clue with programming and software development.
This project is inspired by the work of Johnny Chung Lee.
check out his work here,
Step 1: The Setup!
The vehicle drives on the medium being cut / engraved.
The vehicle is controlled by the computer wirelessly. The path is programmed before hand, for example a 2d part design or a word.
The Wii remote constantly watch's the vehicles position and sends the data to the computer via Bluetooth (a Bluetooth dongle may be required).
The computer then sends signals to the vehicle for its next motion. This helps keep the vehicle on the correct path.
In the current idea, the cutting part is spinning all the time and is constantly engaged with the medium. This can be fixed by adding Z motion to the dremel and wireless control of the motor.
The software is not yet developed, and I don't have the knowlage or ability to programme it myself. The point of this instructables is to put the idea out there for any willing person to give it a go.
This is just an idea for a fun and not very practical project. Other possibilities are a blue ray laser for engraving by burning. However this may confuse the Wii remote positioning.
* It may be better to have an isosceles triangle arrangement of 3 infrared LEDs or 2 LEDs of noticible differing intensity. This should allow the computer to not only read the vehicles position but its orientation. This means the vehicle may not even have to be 'zeroed' before cutting.