CNC drawing device ver 1

Description

For years, I had been thinking about building my own drawing machine. Since I already had a collection of small stepper motors lying around, I finally decided it was time to turn the idea into reality and build one myself.

Project summary

In this project, I built a CNC drawing machine and experimented with several improvements to increase the drawing quality. However, after a number of iterations, I decided to stop the project because the achievable quality did not meet my expectations.

My responsibilities

• CAD design 

• 3d printing and build up

• Programming and testing

Results

I started with the CAD design and built a relatively simple CNC drawing machine. Due to several projects running in parallel, it took a while before I had time to properly test it. Eventually, however, I got the machine up and running.

Claude helped me develop software to convert images into line drawings. Since I was using a Raspberry Pi Zero with limited computing resources, the image conversion had to be kept relatively simple, resulting in fairly abstract drawings.

The drawing machine itself worked reasonably well, but the backlash of the stepper motors was clearly noticeable. In addition, the very basic linear bearings introduced some unwanted movement into the mechanical system, further reducing the drawing accuracy.

I then started looking for ways to improve the linear bearings. I found several designs that used PTFE tubes as simple linear bearings and decided to try this approach. In principle, it worked, but achieving the required tolerances proved difficult. The fit was either too loose, resulting in excessive play, or too tight, creating too much friction. As a result, this solution was not suitable for the application.

At this point, I decided to stop further development of this version and focus instead on a larger-format design with proper linear bearings. Nevertheless, the project was a valuable learning experience and gave me a much better foundation for developing an improved version.

Used tools

SW: Arduino IDE, Fusion 360, Claude AI

HW: 3d printer, soldering, Raspberry Pi, stepper motors