This could be a long and possibly fruitless endeavor, but I'm making a start on it. This time I'm thinking about making a film gate with a claw action to pull the film strip through one frame at a time. As before, I'll probably use my DSLR camera with some macro rings to re-photograph the frames as digital stills.
First of all I found the specifactions for 16mm movie film online, here's the dimensions I am working with.
Here's a first look at my prototype film gate mechanism. I'm designing this in Cinema 4D, outputting .stl files and sending these off to Shapeways to have them 3D printed from black 'detail' plastic.
This version of the mechanism is made of 3 parts, a film channel (shown in yellow), a moving bar with two claw teeth (grey) and a top plate (green) to apply some downward pressure to the film. This is probably the simplest kind of mechanism to go for, although more complicated (and precise) mechanisms than this tend to be used in proper film equipment.
I've already got the first couple of parts back from Shapeways (from a slightly earlier design), Here they are.
These parts do seem to fit the film quite well which is encouraging. As I've found before, getting things 3D printed is very much an iterative process, you design, you make you test; then you do it all again... it's not exactly cheap either.
I've now ordered some more parts to make the mechanism shown above, so maybe in a couple of weeks time when the parts come back I'll have a little more to show here.