Plastic Fabrication for ULF Development

[Rick Olson]

Hi all,

I am looking to make a spiral-type loading reel in order to develop an 8 x 20 sheet of film in one of the larger Patterson daylight tanks. Is there any type of thin plastic sheeting that can be cut and formed to shape then heated or cured in some way to become permanent? I am thinking about trying an art supply store but wondering if someone in the LF community might have a solution.

Thanks,
Rick

[brad martin]

If you have a design a machine shop can manufacture one for you but it will probably be very expensive. I've worked with a number of them and they don't charge for a quote. So it might be worth checking into. I've had (for work) several pieces made from delrin, a very tough and dimensionally stable material that is similar to teflon in appearance and texture.

[Rick Olson]

Thanks Brad ... I was looking for a DIY (do it yourself) option. Professional fabrication can be expensive and I have had two shops already say they were not interested.

Rick

[IanMazursky]

You could try metal forming. Thin rods of stainless steel and a little bit of arc welding isn't that hard to learn.
If you are doing it yourself, you can make it fit the paterson tanks easily.
Or take it to a machine shop and they can form the parts for you.

[Bob Salomon]

Assuming you can find a way to do this and after spending the time and money needed to do this how do you know that it would work?

You know that the Combi-Plan system and the Jobo system do work out of the box.

[Gem Singer]

For 8X20 sheet film????

Wow, the Combi-Plan tank must have undergone a huge improvement since it's introduction 40 years ago!

Did they also improve on the design of the film clip?

[Rick Olson]

This device will be used for extreme minimum agitation. I already have rotation systems in place. Exploring other options for this type of development, as trays will not work for EMA.

Rick

[argos33]

It seems to me that you could fashion some type of plastic reel (like the 120 ones except huge) without too much trouble.

1. Get some 1/8 acrylic or Delrin sheeting and some delrin pipe. (www.mcmaster.com is a good source)

2. Figure out the size spiral you need that will fit in the tank, then cut out 4 circles a bit bigger than that, making sure to mark the centers first.

3. Drill a hole the size of the pipe in two of them, then draw the spiral on one winding towards the pipe hole.

4. Overlap the two circles with holes (the top with the spiral pattern) and tape them together.

5. Clamp the two circles onto a scrap piece of wood or delrin. Using a small plunge-router with a small bit, carefully cut the spiral pattern out of both pieces.

6. Glue, screw or bolt the spiral cut circles onto the plain circles so that when facing each other the spirals go in the same direction. (Not sure what would be best here, maybe a plastic epoxy)

7. Drill holes around the spiral groove on each piece so that chemicals can flow through.

8. Cut the pipe to the exact length required so that when sliding film into the spirals it does not pop out or is too hard to insert. Glue said pipe into holes between the two pieces, making sure the spirals are aligned before it sets up.

You might want to use thicker material so there is more room for error. If the film doesn't slide in very easily or at all you could find some plastic or stainless steel screening to slide into the spirals, then insert the film inside of that.

Hope that helps or at least gives you some ideas maybe. Good luck

Evan

[jhogan]

Any number of online CAD machine shops might be able to fabricate something for you. An example here. There are scores of alternatives...

[Steve Wadlington]

A much simpler approach. Find a 20x24 print processing drum. Slide the 8x20 in film in, add enough developer to cover the film, stand the drum on end for stand developing.