Replacement HP Plotter Pen (DesignMaster series)

thingiverse

This model allows for the use of Uni-ball 207 or Pentel EnerGel refills to be used in old HP plotters. I am using it in a HP DraftMaster RX Drafting Plotter. It will not work in a HP 7475 plotter as they required the short, low capacity pens. However it should work with any HP plotter that is capable of using the larger capacity pens. To assemble, first take the refill and insert it tip end first into Jig. Make sure the tip is touching the bottom of the Jig. Then with a pair of sharp side cutters, squeeze onto the refill right at the end of the Jig. Without side cutters slipping on the refill, pull the refill out of the Jig and then snip the refill. Be careful as ink may leak out if it was too full. I found with the Pentel EnerGel refills, you can take a 4mm Hex wrench and gently push the plastic plug down in a little bit. This will squeeze a bit of the 'follower' (the clear gel between the plug and the ink) out giving you room to cut the end off. Do not squeeze all the follower out as the ink will dry prematurely. Assemble the refill into the Base so only about 1/16" (1 to 2mm) of the refill's ink well is sticking out of the threaded end of the Base. Thread the Cap firmly onto the Base. Your pen is ready to try in your plotter.