Parametric pen holder for CNC

thingiverse

This is a precision-designed pen holder for your CNC, crafted with no moving parts or mechanical play in mind. The ABS material itself acts as a spring, eliminating the need for additional springs or components. It's engineered to be sturdy and stable in both X and Y directions while maintaining flexibility in Z. To ensure optimal performance, you can preload it with an adjustable screw, as seen in the accompanying photo between the bottom leg and extruded aluminum component. I preloaded mine at a force of 5 grams, which is sufficient for smooth writing, and thanks to this preloading, I only need to move my Z axis by 0.3mm up and down to initiate and terminate writing. However, if you do encounter an issue with depth adjustment, rest assured that the ABS part will flex and maintain a moderate pressure on the pen without sustaining any damage. To give you an idea of its flexibility, I deliberately pushed it down 1mm beyond contact, resulting in a force increase from 5 to 10 grams. This suggests that even if your CNC machine is not perfectly accurate, you can still achieve consistent results with this pen holder. The OpenSCAD model included allows for easy adaptation to your specific machine setup.