This was an initial prototype using continuous rotation servos without positioning feedback. Currently working on an updated prototype with structural and positioning improvements.
The water bath is made from a simple tub from Home Depot. The base for both the tub and motion components are two pre-cut wood table tops. I added castors to the bottom of the tub base to make it easier to move while full of water. For the machine base, I used a 4.5” hole saw to cut places for 2L pitchers so that they sit in the water bath. I also cut out a section for the sous vide cooker, and cut off the pitcher handles.
The electronics structure is built on top of a Nema 23 stepper motor for 360 degree rotary motion with position control. It is driven by a 4A stepper motor driver. An 8mm shaft and adapter drives the main support column made from aluminum channel. The boom is made from two flat pieces of aluminum plating sandwiching a continuous rotation servo that acts as a film spool pulley. Film spools needs to be modified with a clip or magnet to attach to a string. Everything is controlled via Arduino.
I love shooting film, but developing takes time and attention to detail. So, iv'e been working on building a film processing machine to make things a little easier. The goal is to make a machine that will develop film without much human input. Besides me being lazy, it should help with processing consistency and reduce development errors. Iv'e got a prototype made and it is working well. The design includes rotary motion, moving the film spool, with a maximum of 5 development stages. Temperature is maintained with a sous vide cooker. Sous vide cookers are excellent tools for hand processing, and I had one on hand, so I incorporated it into this build because it works so well. It will maintain temperate within a half degree margin of error, so it is very well suited for temperature sensitive processes like e6. This apparatus will accept plastic Paterson type, MOD54 4x5, and stainless-steel reels. It has a maximum chemical capacity of 2L, so it will probably do at least 2 reels at a time. I hardly ever develop more than two at a time because the chemical kits I buy are either 1QT or 1L. It also features automatic agitation.