[packetandy] had a problem. He was still into classic analog photography, but local options for development were few and far between. After some frustration, he decided to take on the process himself, creating an automatic development tank for that very purpose.
For black and white film, developing is fairly straightforward, if dull and time consuming. The film requires constant agitation during development, which can be dull to do by hand. To get around this, [packetandy] decided to build a development tank rig that could handle agitation duties for him by wiggling the film around in his absence.
The tank itself is created by Patterson, and has a stick on top for agitating the film inside. The rig works by attaching a NEMA stepper motor to this stick to jerk it around appropriately. Rather than go with a microcontroller and custom code, [packetandy] instead just grabbed a programmable off-the-shelf stepper controller that can handle a variety of modes. It’s not sophisticated, but neither is the job at hand, and it does just fine.
It’s a nifty build that should see [packetandy]’s black-and-white photography on the up and up. Meanwhile, if simple development isn’t enough for you, consider diving into the world of darkroom robot automation if you’re so inclined!
Actually, film does not require continuous agitation. It requires periodic agitation, once every 30 seconds or minute for about 5 seconds. Never seemed all that tedious back when I did wet photography. Of course, back then we didn’t have smart phones to condition us to require continuous entertainment.
Exhausted BW chem + 2 stop push = 35 min dev time, but please keep crying about the kids these days.
Worked for the college newspaper, and was on duty a few nights per week. After a year or so, agitation loses its appeal.
In my day, we had to boil our own mercury. Up hill, both ways in neck-high snow.
The stick is not suitable for in-development agitation. It is used for the first agitations only. If I remember correctly the tank instructions tell also this.
You end up with high risk of uneven development if you don’t rotate the tank completely. “Works for me” doesn’t work; this stick issue has been seen thousands already.
Throw the stick away and use the instructions film manufacturers provide – the instructions are there for a reason. And for some reason commercial tank agitation devices rotate the tank completely.
Hmm. I recall Paterson’s instructions said “invert tank each minute”, then tapping on the bench to dislodge bubbles. Agitator stick optional.
I recall that because tried that with a different style of tank, and promptly dumped the contents on the bench. I gave that tank away. Still have the Paterson.
The worst for me was loading those spiral wire film holders. The film was clipped to the hub and you had to cup the film so the sides would slide between the spirals. Hard to tell if you were misaligned, and hard to tell if you had fixed the problem. Misaligned areas would stick together. Grrr. Many hours spent listening to Phish’s first album, Junta. On a record player.