I am still working on a final design, however I already have a first working microscope, assembled using uCubes:
It features a slightly modified version of an amazing OpenFlexture Microscope (https://github.com/rwb27/openflexure_microscope), which acts as a stage, Nikon 4x infinity-corrected objective, a Nikon tube lens, and a Raspberry Pi 3 with a v2 camera module. Here is an example picture of M. polymorpha gemma sample, which I hijacked from B. Pollak:
I decided I will reassemble the existing setup with a new version of uCubes, and will document every step as I go. So stay tuned.