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rmazzullo
12-27-2007, 02:30 PM
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
12-27-2007, 09:02 PM
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
12-27-2007, 09:16 PM
If the fellow isn't already here, he should be invited.

Neanderman
12-28-2007, 08:01 AM
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
12-28-2007, 08:22 AM
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
12-28-2007, 09:07 AM
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
12-28-2007, 09:25 AM
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
12-28-2007, 07:19 PM
What about flashing edge markings on? Engineering that would be even more 'fun' than the sprocket pucnh.

ben-s
12-28-2007, 07:50 PM
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
12-28-2007, 09:03 PM
hopefully the attached files will make it a bit clearer...

Pic driving LEDs:
http://www.apug.org/forums/attachment.php?attachmentid=9401&stc=1&d=1198897214



Fibre optic head over the edge of the film:

http://www.apug.org/forums/attachment.php?attachmentid=9399&stc=1&d=1198897214



The LEDs flash like this:

http://www.apug.org/forums/attachment.php?attachmentid=9400&stc=1&d=1198897214

Dark Orange
12-28-2007, 10:11 PM
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.

rmazzullo
12-28-2007, 10:32 PM
I have located a source of bulk triacetate 120 (and other sizes) film base in NYC, but they have yet to get back to me as far as their minimum order requirements.

Bob M.
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.

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?

Thanks,

Bob M.

Hologram
12-28-2007, 11:14 PM
They did suggest other places to look, so I have some more work to do on Monday.

www.filmotec.de might be a place to look at...

Photo Engineer
12-28-2007, 11:15 PM
Bob;

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.

PE

AgX
12-29-2007, 02:48 AM
Exposing edge markings by means of an LED/fibre matrix:

ben-s,

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.

ben-s
12-29-2007, 08:07 AM
Exposing edge markings by means of an LED/fibre matrix:

ben-s,

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

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 ;)

AgX
12-29-2007, 09:01 AM
The Ilford edge marking machine is also quite large, so I'm guessing it's rather more complex than this system.

The Agfa machnine would run up to a speed of 200m/min and handle two spools of 3200m.
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...

Photo Engineer
12-29-2007, 12:34 PM
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.

PE

alanrockwood
12-29-2007, 05:00 PM
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...


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.


Alan

Photo Engineer
12-29-2007, 05:18 PM
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.

PE