I've been messing around with camera setup for a new-to-me Optiphot and SMZ-10. I've 3D printed a few parts for testing, which are now shared on Tinkercad.
The trinocular ports on both scopes seem to have an inside diameter of 42.5mm, though I suspect they're nominally 42mm. Printing 42.5mm directly yields too tight a fit, so I settled on 42.3mm, which is comfortably snug.
A tall cap for the SMZ, which has a protruding inner tube:
https://www.tinkercad.com/things/9TT3TrsnaQS
A shorter cap with a wider flange for the Optiphot:
https://www.tinkercad.com/things/08ybmgAsnmG
Presumably this would also fit a Labophot and other xxxPhots.
An M42 screw mount adapter:
https://www.tinkercad.com/things/jbeWzaE2Vg8
This works great with a bellows to get parfocal eyepiece projection. Or, it would if I had the right eyepiece (1x TV relay or 2.5x I guess).
A 46mm filter thread adapter:
https://www.tinkercad.com/things/7krp5X6m108
I printed this for afocal use with the 10 photo eyepiece and Panasonic 25mm f/1.7 (Micro Four Thirds). The notches are there because small threads can be finicky, but in hindsight I don't think they were needed.
I printed these in PLA with 100% infill. There aren't any overhang issues on my printer. My camera is fairly light (Olympus EM5ii); for anything bigger, you might want to thicken the walls or use a tougher filament.
Some Nikon trinocular tube accessories
Re: Some Nikon trinocular tube accessories
Very interesting indeed, may I ask what model 3D printer you used for this?
John B
Re: Some Nikon trinocular tube accessories
I used an Ender 5, which I borrow from my kids. I did this with Cura and Tinkercad (easy for simple stuff, and easy to share) though I normally like to make things parametric with OpenSCAD.