Very nice, but you have to build the machine first. ;)
This talk of PICs brings up the subject of automation.
Currently, the machine is all manual. If you adjust the web speed, you have to adjust the emulsion volume as well. On paper, linking the two to allow the user to dial in an emulsion thickness and a coating speed is a simple. In reality, the system needs to be designed with that goal in mind.
I dabble in automation systems as part of my job and I have the basic hardware needed to do the job. In this case, a Unitronics M90 or twowith the option of upgrading to a Unitronics Vision 120. The benefit of these units is that they are a type of PLC (Process Logic Controller) that have key input and a display screen. Unlike the more chunky and complex Rockwell and Allen Bradley hardware you may pick up for a carton of beer, the software to program them is downloadable from the net, and is free rather than costing an arm and a leg.
However, while the 'brain' of the system is easy to get and to program, you need drive controllers that can talk modbus or similar, (Not gunna happen on this version of the hardware unfortunately) and preferrably some type of feedback system - emulsion rate just requires some fancy (read: expensive) meters unless you happen to use positive displacement pumps such as the Zenith, in which case RPM feedback (in the form of a mag sensor on the pump drive shaft will do. Same method for web feed speed.
Apart from that, automation should be easy. With only a few engineering tweeks you should be able to thread the machine, connect the emulsion hopper, punch in the web speed and emulsion thickness required, and stand back.
The system will turn off the lights, prime the emulsion pump up to the coating head, start the chillers and when the correct temperatures have been reached, it then starts the drive and when the correct speed has been reached and the splice comes past, wind the coating head into the base for a complete revolution then back it off and shut the system down.
The system can then optionally prime another emulsion and do a second (or third) layer.
The user then has to just cut and discharge the finished product before turning the lights back on.
This field is, unfortunately, an area the builder is not familiar with and as he is quite comfortable having total manual control over everything, I am not sure it is an area he has any desire to explore.
I received a message today from the actual sales rep from the company that makes triacetate film base. They only make the triacetate in 'master roll' sizes -- about 45 inches wide, by 1,850 meters long, by 4.6 mils. I would have to buy 6 master rolls so that comes out to about 6.6 miles. I was under the impression from the initial contact that they sold cut sizes of triacetate. Not so. This is probably more film base than we could use in two lifetimes on such a small scale.
Originally Posted by rmazzullo
They did suggest other places to look, so I have some more work to do on Monday.
Dark orange, do you know where the machine builder got his base material from?
www.filmotec.de might be a place to look at...
Originally Posted by rmazzullo
Purchase involves getting up to 8 42" rolls of film or paper with each roll being up to 1000 ft long or more. I've been 'round the bush. Do we keep having to do this until the manufacturers quit talking to us?
Volume sales are the norm and these sales are huge. The contrrol of the machine is critical and difficult. How many times do I have to tell you that it takes people who know what they are doing to buy materials and run these machines.
Exposing edge markings by means of an LED/fibre matrix:
That's the way the industry does it.
At least Agfa (with a homebuilt unit enabling exposing K-code too), and Filmotec, who bought one such machine from them.
I thought so. It orignally struck me that this was how it is done this way when I was looking at a roll of velvia. The text has fine lines running through it
Originally Posted by AgX
I suspect that Ilford and possibly Kodak might use a different system, as their edge markings look smoother.
The Ilford edge marking machine is also quite large, so I'm guessing it's rather more complex than this system
Having said all that, and as interesting as film finishing is, aren't we getting rather ahead of ourselves here? We haven't even sourced the base yet, let alone built the coater ;)
The Agfa machnine would run up to a speed of 200m/min and handle two spools of 3200m.
Originally Posted by ben-s
A lot of technics is used to handle the neccessary precision of down to 1/50mm. I guess that would be overkill for any garage...
Please note that Kodak films have a bar code along the edge as well as the 'logo' so that more informaiton can be encoded in the film. APS was to go a step beyond that. As I said before, I have seen talking prints, or prints with sound that never were released. This would have gone onto a magnetic stripe along the edge of the APS film.
second the idea of plans
Originally Posted by okto
Okto, although I am not really in a position to build one of the machines, I second the idea of making plans available, either for free or for a fee. Aside from the cost of the plans, I wonder what the cost would be for parts.
Also, the comments about kodachrome were intriguing.
As I've said before, a machine on this scale would be about $10,000 - $20,000 to build. A wider machine would be at the upper range of costs. I would go for an 13" machine to allow for sizes from 12" wide by any length. I would design it with 2 coating stations to allow for rollup and longer lengths of film to be coated. It would probably double the cost if you have 2 coating stations.