Hi @Jcr159,
A film scanner basically consists of a film transport system, a lighting system and a camera with its corresponding lens, and on the other hand, the software that allows these subsystems to work in a coordinated way to obtain the desired results.
In my opinion, the most complicated part is the construction of the transport system. Building a transport system from scratch requires having a good design and a well-equipped workshop that allows us to carry it out.
In my case, I do not have a workshop. For this reason I decided to build my scanner using an old projector for transporting the film, which I already had at home at my disposal. In my own home and using basic tools, I converted the old projector into a fairly decent film scanner.
In the forum you have other similar examples.
Good luck with building your device.