Automatic film dev machine

dutchsteammachine · Oct 7, 2019

Brainstorming a machine that can develop film automatically. Controlled by an Arduino or Raspberry Pie

The drum that rotates the baths:

(v0.1)
1. Pre soak
2. Dev
3. Wash
4. Fix
5. Wash
6. Final wash

Baths may be 100mm tall. Drum taller.
Not sure how I should go about equally heating the water in the drum. Any ideas?

Dutchsteammachine.

Luckless · Oct 7, 2019

dutchsteammachine said:
Not sure how I should go about equally heating the water in the drum. Any ideas?

Dutchsteammachine.

The most straightforward method to heat all the drums equally is probably to not heat the drums directly, but rather to add a water jacket around them, and heat the water jacket.

How are you planning to handle agitation?

dutchsteammachine · Oct 8, 2019

Luckless said:
The most straightforward method to heat all the drums equally is probably to not heat the drums directly, but rather to add a water jacket around them, and heat the water jacket.

How are you planning to handle agitation?

The film Dev spool will be rotating and moved up and down inside each bath.

Neal · Oct 8, 2019

I like the idea that you are eliminating all the pumping of fluids.

dutchsteammachine · Oct 8, 2019

The problem with this setup is that the spool must be hung on the development module in darkness, and everything must run in darkness too.

So I've been thinking about using pumps to pump water in and out a development tank and rotating the tank for agitation. This can run in daylight.

I am not sure which would be easier.

Regardless, would anyone be interested in a final product, or perhaps beta-testing a prototype? My location is the Netherlands.

Tom Kershaw · Oct 8, 2019

I'm interested in film processing machines and have a fully dark darkroom but am heavily invested in Jobo equipment so realistically not in the market for a new processor.

AgX · Oct 8, 2019

-) Is this a private endeavour or are you aiming at commercialising? (As there are already machines next to Jobo on the market.)
-) Why do you employ a prebath?
-) Why a processor for b&w films at all?

foc · Oct 8, 2019

I think Kiss Photo has a film processor (back in the mid 1980's) that was like a Dip & Dunk, tanks in a circle with central lifting arm that would rotate, but it was with the film on reels.
Again if I remember correctly the Kiss had problems lifting and moving the reels from tank to tank.

dutchsteammachine · Oct 8, 2019

AgX said:
-) Is this a private endeavour or are you aiming at commercialising? (As there are already machines next to Jobo on the market.)
-) Why do you employ a prebath?
-) Why a processor for b&w films at all?

1. Private, hobby.
2. Because I see some people apply a presoak. Don't do it myself.
3. Given the number of baths, it can easily be programmed for other processi.

cmacd123 · Oct 8, 2019

foc said:
I think Kiss Photo has a film processor (back in the mid 1980's) that was like a Dip & Dunk, tanks in a circle with central lifting arm that would rotate, but it was with the film on reels.
Again if I remember correctly the Kiss had problems lifting and moving the reels from tank to tank.

Kis was attempting to make something very low cost, so it is hard to say if the problems were with the concept or the execution.

Chan Tran · Oct 8, 2019

You can copy the Jobo Autolab design. You can simply buy a Noritsu film processor used. The one for only 35mm is only about $2500. For $5000 you can develop from 110, 126, APS, 35mm and 120.

dutchsteammachine · Oct 8, 2019

If I am going to use a pump system, I think I will make a system that uses traditional agitation.

You place your dev tank in a holder, which rotates the tank according to the program.I may be able to add vertical movement if this is necessary?

I think I can just take kaiser or paterson super system 4 tank (Something that is being made today) drill a hole through the lid and put a hose connector there.
The benefit is that any tank system can be used as long as you are willing to drill a hole through the lid. No proprietary stuff needed. I want to make this universal as possible.

Luckless · Oct 8, 2019

The biggest problems I've run into after spending time working on designs for an inversion agitator that closely mimics how I develop by hand has been how to gracefully transfer chemistry in and out of the tank. [I had been mainly focusing on Paterson tanks, as that's what I have on hand.]

However I am now reconsidering that, and looking more towards something like a Dip and Dunk style with open tanks that the reel is pressed down into.

A darkbag popup tent style contraption would make short work of using such a device in Daylight. Either load film directly in the machine like it was in a changing bag, or design the machine to accept loaded tanks that you drop in, uncap, and align/prep as needed for the machine to pick up.

No real plumbing or pumps, just a robotic arm not unlike what's used for 3D printers to pick up a film holder of some kind and guide to each stage on a programmed route.

My only concern with such a rig would be evenness of development. [I've only worked with full inversion hand held development tanks, so I'm not confident on saying one way or the other if there is a risk of chemical 'settling' and producing some kind of development gradient across the film]

In theory you could design a fairly flexible rig that happily accepts and allows reconfiguration for various sized/style tanks, reels, and holders.

dutchsteammachine · Oct 9, 2019

What problems did you run into when transferring chemicals? Isn't it just as easy as turning the tank upsideup when filling, and upsidedown when draining?

Hmm shit, that would create a vacuum if you were to pump it out and a pressure when filling.

Luckless · Oct 9, 2019

More parts, more modifications, more points of potential failure, more stuff to clean...

Part of my original design goal had been to replicate my hand process as accurately and directly as possible. As I invert the tank by passing it from hand to hand as I turn it over, but also give the tank a 1/3rd twist each time to reduce the risk of turbulent flow patterns showing up on my film.

However that leads me to a lot of problems. Either I need a design that can pull the whole lid off and put it back, or I need a new lid that has two ports in it [one for chemistry and another to let air in].

Beyond that I need some scheme to get chemistry from their storage containers into the development tank, but keeping the dev tank free to invert and rotate. Using pumps and tubes meant either having a system that connects and disconnects from the dev tank [headache point of failure?], or having the store tanks locked to the dev tank and just let them go along for the ride.

That lead me to the idea of just going very far along the 'mimic what I do by hand', and design it in part with a clamping cover, kind of like paint mixers clamp down on a can of paint. Then just pour chemistry in and out... But mock ups for that kind of design grew large, and dealing with smoothly pouring between containers without excessive splashing seemed like a bit of a headache.

Having a handful of containers set up in a tight pattern, and an arm that picks the reels up to dunk and move them from tank to tank as needed is sounding more and more like a simple and sensible working solution that needs far fewer parts and controls.

dutchsteammachine · Oct 9, 2019

Maybe I'll make both as a proof of concept and see which one I, or you guys, prefer.

Starting simple first and adding more features and a user interface later.

Thanks for all your help so far luckless.

I still adore my rotating drum design. But an arm may be easier, less mess with cabling and rotating a heavy mass...

AgX · Oct 9, 2019

Luckless said:
That lead me to the idea of just going very far along the 'mimic what I do by hand', and design it in part with a clamping cover, kind of like paint mixers clamp down on a can of paint. Then just pour chemistry in and out... But mock ups for that kind of design grew large, and dealing with smoothly pouring between containers without excessive splashing seemed like a bit of a headache.

You are late...

https://heilandelectronic.de/tas_filmprozessor/lang:en

https://bit.ly/2p9Rcy0

Luckless · Oct 9, 2019

AgX said:
You are late...

https://heilandelectronic.de/tas_filmprozessor/lang:en

https://bit.ly/2p9Rcy0

Not really, given that they've missed both functionality goals and my price goals.

The processor I want would allow me to set it up with my film and chemistry loaded, and come back to completed and washed film that's ready to hang.
[I would consider a design that hangs its own film, but that seems slightly excessive...]

I also have no desire [or budget] to spend that much on such a project. Plus just buying something off the self would rob me of the fun of tinkering.

AgX · Oct 9, 2019

Yes, but in your post above you already reduced your goals to exchanging the baths by hand, and then your machine, to my understanding, would be similar to that from Heiland. Except for the price of course.

Luckless · Oct 9, 2019

AgX said:
Yes, but in your post above you already reduced your goals to exchanging the baths by hand, and then your machine, to my understanding, would be similar to that from Heiland. Except for the price of course.

Sorry, to clarify the reduced goals was to drop the "Hand Process Simulation", not the Automatic Chemistry Changing:

So robotic arm that picks up the reel(s) of film, and runs down a line of tanks for each step with the needed chemistry.

bnxvs · Oct 9, 2019

John51 · Oct 10, 2019

Small cnc mill in a tent? Reel on the z axis.

I wouldn't worry about agitation at first. Rondinax, Rondix, Jobo, dip and dunk, inversion, figure of eight, twizzle stick only etc. are all capable of souping negs properly once the agitation routine is tuned to that method.

Automatic film dev machine

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