WaterColorBot-style pen holder for DIY Laser By Lenore Edman on June 1, 2014 Jens added a new tool option to his DIY Laser: a pen holder. Due to safety concerns I couldn’t run the laser out in public, but to be able to show of the CNC capabilities I built a penholder. The pen holder design was inspired by the WaterColorBot’s brush holder, with its parallel flexure hinges. This entry was posted in Art, CNC, Electronics, Engineering, WaterColorBot and tagged cnc, diy. Bookmark the Permalink.