CNC drawing

So I tried CNC drawing twice, and both attempts were definitely a learning experience. The first time, the middle section of my design had really delicate details, and the machine went over certain areas too many times. It actually messed up the drawing so much that it nearly ripped through the paper. I probably could have used a softer pen or marker, but I wanted fine details, which meant I needed a sharp tip.

On my first attempt, I also had the settings completely off, which caused the machine to skip a lot of intricate details. The way I originally organized the G-code made the process pretty messy I had planned for one section to be completed before moving on to the next, but I quickly realized that some parts of the artwork needed to be sorted by the Y-axis and others by the X-axis. So, after that first run, I went back and redid the G-code, organizing certain sections differently. I also change the desighn just a bit to help.This actually helped a lot because it let me control which areas had fine details and which could skip unnecessary lines.

before

redesign

Another issue I ran into was that, at some point, I accidentally raised the drawing higher in Rhino, so nothing was on the same plane. That was an easy fix, but I also noticed that I had set the pen to lift way too high between lines. I adjusted that for the second attempt, though I think I could lower it even more next time.

Resizing was another struggle especially in the beginning. I eventually just went into the G-code manually and set everything to inches instead of millimeters. One thing I wish I had done earlier was adjust the feed rate in Grasshopper. Certain parts of the design could have been done really fast, while others needed to be slower. On my second attempt, I ended up standing by the machine and manually adjusting the jog rate and feed rate whenever it got to a section with fine details. This worked, but it also meant that some parts of the artwork had wiggly, uneven lines, while others (like the mirrored butterfly shape) were really structured which was kind of annoying.

Another challenge was organizing the G-code within Rhino and Grasshopper. Since I had different sections of the artwork, putting them all into one G-code file was nearly impossible. I had to manually copy and paste everything into one document, making sure the pen lifted and moved correctly between sections. I know we were supposed to switch pens for different colors, but my design was originally meant to be one color, so I just stuck with that.

On my second attempt, I ran into a new problem my pen ran out of ink mid-drawing. When I replaced it, I accidentally re-zeroed the machine completely, making the entire drawing misaligned.

             

To fix this, I used the CNC machine’s display to find where it thought the corner of the artwork was, compared that to the actual corner, and marked the offset with painter’s tape. Then, I moved that tape to where I estimated the correct zero point should be. Surprisingly, this method worked, and the second attempt lined up perfectly afterward.