16mm Film Developing Tank

thingiverse

Inspired by mb_Makers LOMO-esque tank, this developing tank attempts to make more efficient use of chemistry. It is capable of developing up to 15 meters of film at once, and can be printed on a 220mmX220mm print bed. What differentiates it from the earlier design is that it is an upright rotary style tank that uses less than half the chemistry, allowing you to develop 15 meters in just 450ml of liquid, which is roughly the same efficiency of developing the equivalent area of 35mm film in a stainless steel tank. I've made the pour/drain holes large enough for quick filling. An initial test showed 15 second fill times and 5 second drain times, which should be acceptable when executing time sensitive color processes. The carryover left in the tank and the light baffles should be minimal. ~10ml or so. The reel is relatively easy to load if you set it on the lower tank and slowly crank the film on, but I recommend practicing in daylight and then in dark with a test role a few times to get the feel of it and recognize when it isn't loading correctly. if using 1R film (single perf), I recommend putting the not perf side into the spiral, even with super 16. I haven't experiences any uneven development where the film is in the groves, and it is less likely to bind or tear when loading without the perfs. If you are loading an entire 50-odd feet, you can tape the end of the film onto the side to make sure it doesn't come unwound during development. When developing, I recommend turning the crank counter-clockwise to help prevent the film from unwinding. Constant slow agitation seems to work well. About one rotation every 3 to 4 seconds. This design has not been thoroughly tested yet, but I have run a couple hundred feet through it and after I got the hang of loading it right, it seems to develop very well. Don't print the "cutaway", which is an assembled model shown as a reference. You will need to print 2 of each washer, and 4 latches. Everything else only needs one print. A final note: I might recommend using this tank for 1 use baths, and using mb_maker's tank for reusable baths, as the rotary style can aerate and exhaust chemistry. Once you have reached your stop bath step, your film is light safe so you can open up the tank and easily transfer it.