This is The Doctor's Space Time Visualiser as seen in the Hartnell Story 'The Chase'. Scaled for 5-1/2" action figures.
Rigid ink PLA
Only the Main Front ring needs supports. The rest of the model can be printed without.
You need to print 2 copies of 'Side_Piece.stl' and I think 8 of 'Peg.stl'.
The 3 back pieces will only assemble correctly one way round, so if uyou are painting an image on the screen make sure you get it the right way up.
When it is assembled, it is very forward heavy. The Recess in the back of 'Back.stl' is to allow you to counter balance it with metal coins or washers.
Once the back cylinder and legs have been assembled you will notice a recessed square in front of the screen area. This is intended to hold a piece of clear acrylic.
I have already succeeded in breaking the lever off the top left control, so I replaced by drilling a fine hole and glueing in a shortened sewing pin.
Remember to prime it before painting. I haven't been able to find any colour reference material, so I'm going with a white body, black in the recesses and in the side pieces with a black wash screen and silver & red highlights. I'd recommend painting it before gluing it together - it does need to be glued.
It has been scaled from screen grabs from the BBC DVD of 'The Chase' and from other reference material I got from the internet.
I was unable to find any images of the back of the device, so the back is designed with educated guesswork. One partial photo of the side shows that the back was drum shaped, so I have guessed that it is roughly the length of two sixties cathode ray tubes.
I have deliberately left the words off the outer ring of the screen. Having the names of 8 of the planets from our solar system (Pluto included Mercury omitted) seemed out of place on an alien device that can view the past of anywhere in the universe.
The legs of the original were on castors. I have omitted that detail.
I had intended to include a slot so that images could be displayed, but I was so taken by the curve of the circular screen that I decided against it. If I ever find a magnifying glass of the right diameter I may revisit that decision.