Former 35mm projectionist here (see https://news.ycombinator.com/item?id=35887809). I also worked with 16mm projectors and cameras as a student.

It's cool to see that people are still interested in this media, and trying to fix a number of problems. There are a couple things about this proposal that are admirable, such as switching to dimmable LEDs and open-source/3D printable parts.

I also liked the bit about not trying to reinvent the wheel ("We believe that especially the central mechanical elements of the old projectors – claw mechanism, shutter wheel and film transport - are in most cases so well engineered that a new development here would be a waste of time and energy.") But what follows is an extensive list of new specs that would make the project vastly more complex.

16mm/35mm is already fading, with a finite population of prints that dwindles every year as film deteriorates or reels are lost/destroyed. Some of the technical features ("Manual vario-speed from < 1 to 30 FPS") are a niche within a niche. Really, how many artists or experimental studios are there who want to play back a 16mm print at .75 FPS? Who would watch them?

This project would be far more realistic if such features were scaled back and the focus was on getting a bare-bones, open source projector that works with 16mm optical film (the majority of existing stock) as well as some of the low-hanging fruit on the list. I think is doable. Low cost, simple plastic film projectors were once a thing with another type of film (Super 8, see https://en.wikipedia.org/wiki/Super_8_film)

If hard stuff is added to the list, at least focus on practicality for a wider range of people, such as a tool to safely evaluate print quality before playback at normal speeds or some sort of print cleaning mechanism for reels that have been sitting in someone's basement for 30 years.

>16mm/35mm is already fading, with a finite population of prints that dwindles every year as film deteriorates or reels are lost/destroyed.

They are still publishing films in 35mm and at least in popular US cities the format has a following. For example in 2021, Last Night In Soho was printed in 35mm. To be fair the 35mm print was only exhibited in some select locations and only for special screenings. But then we also have 70mm IMAX that despite only has X number of screens left, still manages to attracts sold out screenings for weeks whenever a film (Like Oppenheimer) appears. I also spoke to the people running the Barrymore Film Center in Fort Lee, NJ (They screen 16mm, 35mm and 70mm and they promote Fort Lee as the birthplace of the American Motion Picture Industry). They told me that you can order up thousands of different 35mm films from studio's storage centers (I think there are only two left in the country) and the main issue is delivery costs make it usually not worth it to screen most films.

I am closer to middle age but I have met a lot of youngins who are die hard film people.