I recently developed a simple printable pen holder for my PlotterBot. Although it worked wonderfully as a pen holder for single-line drawings and although I had designed it to work with a servo for pen lifts, I had literally never tried actually using it with pen lifts until yesterday.
Above is my first attempt to draw vectors with pen lifts and, frankly, it came out beautifully. The design of the pen lift system could not be any simpler. The pen holder has a mount for the micro servo which holds it as close as possible to the wall-facing surface of the pen holder and a rectangular hole for allowing the servo’s arm to sweep through. I was concerned that the sweeping action of the servo arm would cause a slight stray mark on the paper.
Despite my concerns, the pen lift test was successful. It really came down to a matter of balance. Once I had swapped in a different pen lift arm and connected the pen lift servo cable, I was able to easily adjust the balance by changing the location of the filament attachment. With the proper balance achieved, the pen lift essentially worked flawlessly.
Today I tried my longest drawing ever, an 8-hour process, with voluminous pen lifts. The result was… amazing.
Stay tuned for a picture.