A linear clock was built to move along a track pointing to the time. At midnight, it drives back to 12:01 AM in exactly one minute. The car’s power is supplied by small a stepping motor (28BYJ-48) driven by a Raspberry Pi Pico and the supplied driver. See the included WORD document “Linear VW clock.docx” for details regarding the function and Python program.
The track is too long for the Prusa print bed, so it is broken into three inter-linking parts and super-glued together. The car is cog driven, so is very accurate.

Prusa

i3 MK3

No

Yes

.15 mm

Be careful pulling the infill out, for the pointer can easily be broken off.
The body of the car is then painted with XTC-3D and allied days to harden for a shiny body.
Fingernail polish was used for the bumpers and the lights. Acrylic paint was used for the windows.

The body of the car is then painted with XTC-3D and allied days to harden for a shiny body.
Fingernail polish was used for the bumpers and the lights. Acrylic paint was used for the windows.

I wanted to build a linear clock and wanted it to re-set itself to midnight + 1 minute each evening. Originally, I was going to have the carriage hidden behind a board with a pointer reaching from behind, but then my wife Sharon suggested using a VW car. I found a car in Thingiverse (lost the “original” or I would share it here). Had to hollow it out to fit the chassis with motor and cog wheel sticking out the back. Originally, I drove the wheels, but friction made the car less than accurate, so I went with a cog and 3D printer track.