This choice turned out to be very convenient for working around a mechanical issue ... the servo up and down accordingly while drawing to keep the pen on the paper. Some custom-written software ...

Powell National Air and Space Museum Drafting Pen, William J. Powell National Air and Space Museum Pens, Lindbergh, King Collection National Air and Space Museum Pen, Lindbergh, King Collection ...

One 24-count pack of BIC Xtra-Strong Mechanical Pencils With Erasers Thick lead mechanical pencil offers dependable performance with break-resistant 0.9mm lead Lead advances quickly and erases ...

which provides just enough pen-to-paper pressure to reliably draw lines without lifting off or scratching the paper. We can’t help but be impressed with the overall look of the machine ...