What is it? Why doesn't it work?

The Wheelwriter arrived in a rather poor state, rather dirty and some minor parts dislodged or broken. The first problem I noticed was no hammer action (that's the part that strikes the "daisy wheel" typing element through the ribbon against the paper, printing the character). Solving this required a replacement part which would be pretty expensive to get internationally. I decided to go different route - making it myself! At first, I tried making it with a conventional filament 3D printer but the part fell apart, it definitely called for a different printing technique, if not turning it on a lathe out of a teflon rod. I went for SLA (resin) 3D printing at our local hackerspace. We decided to make three of these parts, on different supports, as we weren't sure which would work... and that was a good idea as two parts were lost, only one survived. It made it into the typewriter - but that's another part of the story...