I recently got a Panasonic typewriter (RK-P400C) that uses pens to actually draw the letters. These magical mechanical devices were basically plotters. The only problem was the typewriters use of proprietary ballpoint pens that have become long obsolete. So I accepted the challenge and made a marker for it to use.
To do this I measured the original pen dimensions using some digital calipers and made a cut off of brass tube stock (Src: K&S Metals). The rest was some trimmed to fit maker pen guts from the local reuse store. I suggest soaking out the ink as much as you can with with 2-Propanol or ethanol. Just make sure to take caution as these are very flammable substances and the fumes are an irritant. I am going to see if I can make a cap for the end of the tube but as a temporary fix I just used hot melt glue for testing.

I want to refine this design and maybe develop some more cartridges for various sizes and media types.
I hope that this inspires others to make pens and use these amazing machines of the past.
Please support your local reuse store.
Thank you and take care of each other.
