What it is
A small pen plotter. The pen moves left and right on the X axis, and the pad of paper moves in and out on the Y axis. Everything except the motors, needles, servo and screws is printed on a Bambu P1S.
Version A reuses the test axis from the stepper work: turned upside down on two legs for X, with a second test axis lying front to back underneath for Y. A servo lifts the pen, and a rubber band pulls it back down onto the paper.
First plot
Its first picture is a "hypnotic H" for HYPNOCHIP: the H's outline in five rings 1.3 mm apart, drawn as one continuous line. It's 40 × 40 mm, about 983 mm of line, and takes roughly 100 seconds. All five rings came out closed and in the right shape.
While it plots, a Nextion display draws each line as the pen finishes it, with the pen position and state beside it.
Known issues
- Backlash on X. Rings on one side merge while the other side's spread out, which points at about 1 mm of play each time the axis reverses.
- Ink bleed. A Fine Point Sharpie on post-it paper spreads to about 1.5 mm.
- Reach. The first baseboard limits how far the pen can travel on Y, so drawings are shifted 18.5 mm up the pad until a new baseboard is printed.
The whole build, including the broken first frame and what the first plot revealed, is in the notebook.
