Pretty clever, and definitely something I could imagine making work in the machine.
Maybe of interest I got a quote from the only place I'm aware of in my country (New Zealand) that processes E-6 sheet film and they want $17 NZD per sheet of 4x5 processed...
Also currently getting quote for 3D printing some prototype components and received a shipment of sample power supplies today, things moving along at pace.
New post, this time with detail of the developing tank design.
http://midtonemachines.com/news/the-develop-tank/
I've also included a shot of some parts I've ordered in for prototyping and I have some 3D printed developing tank pieces on the way for doing fit and functional checks before getting the final versions made.
Great work! I've never seen a tank with a horizontal seam like that. Making it leak proof won't be a challenge?
“You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
― Alexander Den Heijer, Nothing You Don't Already Know
I've been doing fine processing B&W with my Patterson tank and SP-445. However, if I read it right you're designing your machine to do C-41? If so, yes I'm interested. Mostly 4x5 but also 35mm and 120.
Kent in SD
In contento ed allegria
Notte e di vogliam passar!
Peter, the now discontinued Phototherm used a very similar tank and I can see why after going through the design process myself. Because the liquid level never gets above just under half-way up the tank the seam and spindle pass-through only need to be light-tight and not water tight. The JOBO design means there's no seam but because the entire tank rotates you can only get chemicals in and out through the middle of the tank, which means you need a lifting mechanism as well which this design doesn't.
Kent, yep this will be capable of doing everything, C-41, E-6, B&W, either with standard pre-set programs or whatever you want to program in (I plan for a large touch screen and some buttons as the interface). Personally I really want it for doing 4x5 E-6 film but I also shoot a lot of 4x5 Ektar and 35mm of all types.
Hi there, cool project just like an updated Phototherm, I am not sure if the hairdryer is used to maintain temp or just drying?
I have also played around with silicone heaters on tanks metal and thermoset plastics, I am not sure how they would fare with thermoformed 3D printed plastics after a while. Something you may need to design for, or perhaps have a stainless steel element sealed on the bottom (I have done this for my nova clones)
Otherwise, why not make use of spindle for temperature maintenance (although close to film) which brings me to another question; the chemicals will be preheated before coming into the tank correct?
➟ The Container Lab
➟ www.thecontainerlab.com/blog
Yes the bulk of the heating is done using an immersion heater in a separate tank prior to pumping into the development tank, heating the development tank is just required to prevent the chemicals cooling down over the few minutes they're in there. The final tanks will likely be made from a polyurethane compound using vacuum resin casting (I don't think production volumes will be high enough to justify injection molding) which has a heat deflection temperature around 72 degrees Celsius. Realistic film developing process temperatures will be more like 40 degrees C so I don't think there will be a problem with deformation, but if there is during development I might have to look into more heat resistant plastics.
As I mentioned in the blog I'd rather not have any kind of electrical contacts on the developing tank because they're sure to get unreliable eventually given that the tank is being connected and disconnected every cycle. This means that any temperature maintenance has to happen from the outside of the tank.
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