If you saw our previous YouTube/blog on my 3-D printer attempt to make a pen blank, you know it was a complete failure. I had hoped to be able to produce a conventional-sized pen blank and then turn this blank into a unique shape. I had used a variety of tool types but with no success. I also found that trying sandpaper was not a good idea in that the friction heated up the plastic to the melting point. Several viewers suggested printing up various other types of blanks, so I decided to try printing a cylinder to match the required barrel size for a pen.
The pen kit I selected was a PSI Woodworking Products #PK-PENXX “Slimline – Pro” Gelwriter Click Pen. I also used a #PK-PENXXBU 3 piece bushing set. The two barrels for this pen are each 2 1/32-inch long with an 8mm hole for the brass tube insertion. The outside diameter of the bushings is about 10.7 mm. This would set the turn down diameter for the ends of the pen barrels.
Using the 123Design software supplied with the Dremel 3D printer, I designed a 10.7 mm diameter cylinder 2 1/32-inches long with a 8mm diameter hole. I exported this to the Drexel 3D printing software. Using the white filament, I printed one set of pen barrels.
The 8mm holes appeared to be too tight to insert the brass tubes so I decided to take an 8mm drill bit and ream out the holes to the proper size, BAD IDEA!! The friction of the bit generated enough heat to reduce the barrels to a white plastic blob hanging off the drill pit. So I took a set of barrels and tried to press-fit the brass tubes. It worked!! And the fit was so tight that glue was not necessary. Using two barrels with brass tubes inserted, I built up one of the “Slim-line Pro” pens. This was a test, so I made no attempt to apply a finish to the plastic. I would not recommend this otherwise. The texture of the plastic barrels is not mirror-smooth and would be easily stained under normal use.
On to another pen build… taking two more barrels, I press-fitted a brass tube into each barrel. I then used the bushing set to mount the barrels on a pen turning mandrel and set the mandrel into the head stock and tail stock on my lathe. Using Tulip Red Gilders Paste Wax, I applied two coats of wax, wiping off the excess and buffing after each coat. Following this step, I applied nine applications of thin CA glue. After this glue cured, I took Micro-mesh wet-sanding pads and sanded the CA finish from 600 to 12000 grit. I followed this up with a plastic polish. The final pen build is satisfactory but the surface of the barrels has a slight ripple that can’t be covered over with thick CA glue. In the future, I may try some different colored filaments. I have also air brushed 3D builds with some success. An air-brushed design protected with CA glue might be a good option. More on this later.
Here’s the You Tube video of the process: