Film coating machine (homemade) on Flickr

[rmazzullo]

Originally Posted by Photo Engineer

Since coated width must be narrower than the support for technical reasons, and the edges are defective, this method would either be extremely messy causing loads of defects, or produce a product that is underwidth.

It is better to coat wider and cut down. This has been the experience of ALL manufacturers to date.

PE

Dang. Thought I could get around slitting and perforating the film after the run.

[okto]

Wow. I can scarcely contain my excitement about this, being someone who got into film after it was essentially obsolete. One of my greatest personal worries is being stuck in a world in which 35mm film is no longer produced.

I'd love to see the plans/information on this machine be made available for the community; I wonder if our unnamed wonder chemist would be amenable...

[JBrunner]

If the fellow isn't already here, he should be invited.

[Neanderman]

Originally Posted by Photo Engineer

It is better to coat wider and cut down. This has been the experience of ALL manufacturers to date.

I would think, too, that coating pre-perfed film could lead to all kinds of issues of un-evenness.

Ed

[rmazzullo]

Perhaps one of the drive rollers towards the end of the run can be a sprocket punch / film slitter. What needs to be determined is if it would be a rotary punch, or something intermittent, perhaps driven by a geneva mechanism, or rotary cam, or something along those lines.

Timing it would be 'fun'.

Bob M.

[ben-s]

Originally Posted by rmazzullo

Perhaps one of the drive rollers towards the end of the run can be a sprocket punch / film slitter. What needs to be determined is if it would be a rotary punch, or something intermittent, perhaps driven by a geneva mechanism, or rotary cam, or something along those lines.

Timing it would be 'fun'.

Bob M.

I've been thinking about this quite a bit, and came to the conclusion that it would be a bad idea to make slitting/chopping/perfing part of the coater's job.
It would limit you to making only one format on that particular machine.

If you coat a "master roll", and chop that up in another machine, you immediately have a coater that can produce many formats - which, given the low demand for film is quite useful.

[rmazzullo]

After thinking about your post, I have to agree with you. Separating the two tasks into 2 machines makes good sense, and reduces complexity quite a bit.

Thanks for the second look, Ben.

Bob M.

[okto]

What about flashing edge markings on? Engineering that would be even more 'fun' than the sprocket pucnh.

[ben-s]

Originally Posted by okto

What about flashing edge markings on? Engineering that would be even more 'fun' than the sprocket pucnh.

Oddly enough, I think that would be pretty simple.
A line of LEDs shooting into small fibre optics arraged into a line could be driven by a PIC to print text in a similar manner to "POV toys"
http://www.ladyada.net/make/minipov2/index.html

These things work on persistence of vision, and basically flash out a message on one line of LEDs. As you swish them through the air, their message appears, courtesy of the persistence in your eye.

The same trick would work with film. If you really wanted to be complex, you could hook the clock input of the PIC to the speed of the film - I doubt this would be necessary though...

[ben-s]

hopefully the attached files will make it a bit clearer...

Pic driving LEDs:




Fibre optic head over the edge of the film:





The LEDs flash like this: