Machine loading of developing reel?

[Stoney3K]

I've been loading up my Paterson-style reels by hand for some time now, and even though it's easy to do, there may be a more reliable (and lazy) way to do it, especially when you're in the field. With a recently purchased 3D printer, I got an idea...

My idea was to create a Raspberry Pi/Arduino-powered "micro-lab" which is similar to the mechanical processors that were built by Polaroid: You would drop your film spool in the machine, tension it up, close the box, and the machine would do the rest: spool up the developing reel, fill the tank with the appropriate developer/fixer/bleach for that particular film, and agitate. In the end, the (developed) film would be dried and rolled back into its original canister.

At least, that would be the ultimate goal.

So I wanted to break it down into more tiny steps, the first challenge being: to spool up and un-spool a developing reel in an automated way. I've looked into a few ways to do it, here's the three I came up with:

• Feed the spiral-shaped reel from the outer edge using a pair of rubber rollers/sprockets which transport the film. Probably easiest to build, but how will it un-spool? Will it cause jams when spooling?
• Feed from center and let the film settle in the grooves, just like a Rondinax. May be the most viable solution, but can anyone tell me if the film will be damaged by bending it inwards when spooling on the reel?
• Use a regular spool together with a film apron. From a construction standpoint, this is dead easy as you could just build a motorized "tape recorder", but film aprons are hard to find. Would it be possible to make them from scratch?

I know the Polaroid processor uses a simple film apron which also carries the (sludgified) developing agent and which is simply spooled onto a roll at the end of the machine. Has anyone ever tried to load a developing reel in a "mechanical" fashion and care to share about it? The first challenge I want to tackle here is not necessarily a photographical or darkroom challenge, but more of a mechanical one.

 

[Peltigera]

Why? Apart from the fact that you can?

 

[Stoney3K]

Why? Apart from the fact that you can?

Just that. The general idea of building a push-button style micro-lab is a challenge in itself.

If I want to get my film developed fast and reliably, I'll just drop it in a regular developing tank or send it off to a pro lab.

 

[ac12]

I don't know how the small automated machines in the drug store works. But to me, a continuous pull strip would be more reliable. No hassles of getting the film onto and off of a reel.

I do not think that your 3D printer will handle the chemicals. From the few samples that I have seen, the results are somewhat porous. The chemicals will get into the plastic and be a PiA to clean out. Unless you use acetone to melt the surface smooth.