Automated desktop Film Processing unit -thoughts please

[h=2]Automated Desktop Film Processor query - Fuji FPM100-a[/h]
Ray

Acufine? Dafine? See link below.

They're the quickest that I can think of, but still not quick enough unless you do some custom exposures..

http://www.digitaltruth.com/products/acufine_tech/acufine.pdf

Before you put lots of effort into this processor, bear in mind that you are likely to get 'banding' or 'waves' where the meniscus jumps during the initial immersion in the developer. The distance between each jump, probably about 3mm, represents a significant percentage of the total development path length and therefore development time. I am not familiar with the Fujifilm FPM 100-A but experience with similar machines suggests that this banding might be a problem. Fuji may already have solved this problem by positioning the entry-roller pair at the liquid surface, creating a bead of developer that rolls over the emulsion as the film is immersed. Another idea that occurred to me is to agitate the developer surface slightly, perhaps with a buzzer or eccentric drive, so that the constant motion reduces the banding to an insignificant length.
If you can find the bits you may be able to reduce the speed by changing gear ratios or pulley diameters.
To control the drive motor speed, you need to know the type of motor. There are basically three families; stepper, AC (shaded pole) and DC. Stepper drives are infinitely adjustable, to a crawl if necessary, controlled by an oscillator with a potentiometer adjusted with a screwdriver. Their consistency is excellent. The speed of small AC motors can be adjusted with the controllers sold for fans, but there is a risk that they may not start (stall) if they are set to run very slowly. DC motors can also be controlled with appropriate circuitry.
The temperature control is probably also set with a potentiometer.
It goes without saying that you will need professional help if you are not familiar with electrical machinery. But it could be a thoroughly worthwhile project.

you could alter the gearing ratio to slow it down. And I think the idea of introducing agitation to the developer bath is a good idea..

Also have you taken the operating temperature of the machine into account regarding processing time? I worked with a guy who used to process the photo finish photos at the horse racing back in film days....5 sec dev, 5 sec fix....10 sec rinse and wet print the neg for the judges...

Thanks for replies.... the total develop,fix,wash and dry time is three minutes -dry undeveloped to dry developed. Because the machine uses one motor with chicken-feeder gearing for all three solutions -a common rail with worm-gear, so changing gearing just for the dev is not possible, and the motor itself has limited speed adjustment. The other solution is to use very rapid developer, but Im not aware of anything that develops in 30 seconds that is reliable . My next stop is an electrical engineer. Thanks for all your comments

Assuming that slowing down the whole processing chain is acceptable, then you can almost certainly reduce the motor speed.

Is the motor AC or DC? Since you say it has "limited speed adjustment", I'll assume DC. I would try putting a switching regulator in the motor's supply (search for LM2596 on eBay, about $1) to slow it down; just don't lower the voltage so far that it has insufficient torque to drive the gearchain.

Just an out of left field question: can this thing do continuous feed, or does it require that the sheets have a normal length? Just imagining turning one into a tabletop 10" Cirkut film processor...

Duncan

raykayjay61 said:

[h=2]Automated Desktop Film Processor query - Fuji FPM100-a[/h]

I found a Fujifilm FPM 100-A desktop film processing unit online, originally used for developing, fixing, washing and drying xray film for a vet practice.

My immediate thought was it might be able to develop large format negatives and a dummy run with some rubbish film indicates it will handle 4x5 and 5x7 sheets just fine. It tractor feeds the negative in one end and dip and dunks then dries the film, popping it out the other end in short order.

My question is- has anyone else used or modified one of these units for this purpose? I need to know how to slow the feed down so that negatives spend 6 or 7 minutes in developer instead of 30 seconds.Between the chemical pumps, the chemistry heaters and the drier unit, simply reducing the voltage through a Pot is not an option. Any thoughts or experience on the issue would be appreciated. Presently it takes just three minutes to develop fix,wash and dry a negative up to 11x 14" -far too quick for any developer I know of.​

Ray

Click to expand...

There are a lot of large format photographers that would love to have some way to process X-ray film. Myself included. Due to the 2 sided emulstion, standart tube processing is not practical.

frobozz said:

Just an out of left field question: can this thing do continuous feed, or does it require that the sheets have a normal length? Just imagining turning one into a tabletop 10" Cirkut film processor...

Duncan

Click to expand...

Well Duncan the handbook says it can process up to 32 sheets of 17x14"per hour down to two 4x5's at once. I have run 4x5s and 5x7's through just fine.
It tractor feeds dry film through dry rollers and once you close the lid on the tractor, you can turn the lights on. It dips film into developer at 75 degrees, then into fix, then a cooler wash and then a warm air drier. I got quiteexcited thinking about film, but naturally it has been said to me that it could make a paper developer as well. The tanks hold up to 3 litres of chemistry and have replenish bottles that top up based on what has been removed. Here it is - literally sits on my desktop
http://www.bluesky.com.ph/brochures/pdf/fpm_100a_fuji_film_processor.pdf

Given most vets are turning digital, there msut be a few of these going for scrap. Mine cost $2 with a 20 litre bottle of fixer and all the bottles, which is why I am excited.

Wow, that is pretty tiny - about 2 feet wide by 3 feet deep for footprint.

So it sounds like maybe it could do continuous feed, as long as I didn't turn the lights on?

Duncan

Yes.. continuous without lights, but it does have two large red lights on it that I have taped over so I do not fog standard film. I wish now I had some Xray or ortho film to play with.... for smaller runs of film, it would be easy enough to do in a dark room- the chemistry is heated for you, replenished for you.... only thing you need to be sure of is that the last piece of film has fully entered the feed. I spoke to an electrician today who is confident he can slow the rollers down, so I think this is going to work!

raykayjay61 said:

[h=2]Automated Desktop Film Processor query - Fuji FPM100-a[/h]

I found a Fujifilm FPM 100-A desktop film processing unit online, originally used for developing, fixing, washing and drying xray film for a vet practice.
My immediate thought was it might be able to develop large format negatives and a dummy run with some rubbish film indicates it will handle 4x5 and 5x7 sheets just fine. It tractor feeds the negative in one end and dip and dunks then dries the film, popping it out the other end in short order.
My question is- has anyone else used or modified one of these units for this purpose? I need to know how to slow the feed down so that negatives spend 6 or 7 minutes in developer instead of 30 seconds.Between the chemical pumps, the chemistry heaters and the drier unit, simply reducing the voltage through a Pot is not an option. Any thoughts or experience on the issue would be appreciated. Presently it takes just three minutes to develop fix,wash and dry a negative up to 11x 14" -far too quick for any developer I know of.​

Ray

Click to expand...

It's funny that you post this now. I'm currently experimenting with my own dental x-ray processor for processing of 110, 135 and 120 film. It's remarkably similar to the machine you're looking at. It has a fast setting of 3 minutes, a 4.5 minute setting and a 6 minute setting. The developer is warmed to 28 degrees Celsius which is why I think the development times are so fast. Those times I quote are for developer, fixer, rinse and dry so these are pretty fast transit times. I use dental x-ray developer/fixer which is not labelled to provide any more insightful information to help me figure things out. To be honest, I really have to question about the 3 minute time your vet x-ray processor takes. I'm wondering if you're seeing some marketing information and not your full options with this processor? My dentx 810 basic is marketed as having a 3 minute development time, and it is capable of producing a usable image in that time, BUT the results are not archival quality. They discolor within a year and are no longer usable. That fast development time is for immediate emergency use where you want to see a damp negative as fast as possible so you can move on with the surgical procedure. I strongly suspect that's what you're hearing about here. My dentx also has a button to select either a 4.5 minute and a 6 minute transit time. Our large films require a 6 min transit time. Maybe this vet model offers these modes as well? I would think it would have to. I'm not directly familiar with how stiff/flexible 4x5 and 5x7 film is but we use a panoramic negative at the office which are single 5x12 sheets of film. They are fairly stiff. There is no curl whatsoever in this film. Again, I have no experience with large format photographic film but if it exhibits curl in any way it will get stuck in the rollers. That's currently what I'm battling with my own development efforts. I need to staple a leader (usually a dental xray) to the front of my 35mm film to keep it from curling and wrapping itself up in the rollers. Another thing you may not be aware of is that these xray units usually require a direct connection to municipal water. They also are usually attached to a silver recovery unit before draining out into the municipal sewers. You may be able to rig something up here though to meet these requirements. They also require a large amount of solution per tank.

Usually these processors are a series of rollers driven by a chain connected to cogs in each roller. There is a developer tank which then feeds directly into the fixer tank. There is no water/stop bath in between. Once it's fed through the fixer tank it is washed and finally dried. Film comes out completely dry when run through on the 4.5 minute setting or longer. It makes for dust free negatives, which is very nice. Not sure if this helps but it's definitely food for thought. They do require a fair amount of maintenance- oiling, cleaning of rollers, etc... and the rollers are prone to warping when they are allowed to fully dry out and are left like that for a long period of time so be prepared for that.