It's not difficult to develop your own film at home, especially black and white film. Don't get me wrong, it's still painful, but it's not difficult. However, there are things you can do to make your life easier.
Someone named packetandy decided to make your life easier by automating some of their processes. He built his own automatic developer tank and made it available to all of us.
Return to film photography
The beginning of packetandy's post on Instructables is a bit like my own return to film photography. However, it was in his 2012 that I did it. However, even 12 years ago, the cost of having my film developed on the high street was already far more than I could afford.
And I very much relate to his description of the tedious nature of developing black and white film at home.
Developing your own black and white film is not difficult, but it is tedious. You'll have to watch the clock for minutes on end, shuffling the film every 15 to 30 seconds, which isn't great for people who are generally lazy and easily distracted.
How much or how little you need to stir depends on a variety of factors. The developer being used, the dilution (concentration) of that developer, the film stock being used, the temperature of the chemicals, etc.
Keeping track of all these combinations and doing it manually each time you develop a roll is a process that can take up to about 15 minutes if you're pushing the film, but it's very tedious.
I didn't think to automate it like packetandy. Even though the enlarger had an automatic light. Of course, back then he didn't even have a 3D printer. Not for me anyway.
Easiest solution – with a caveat.
At the beginning of the development process, packakendy asked itself several questions. He wanted to determine all the pros and cons of different agitation practices. He came up with some specific design goals.
It was necessary to be able to use multiple sizes of developer tanks from a particular manufacturer. In this case, Patterson. Both continuous and intermittent agitation had to be provided. It needed to be easy to design, develop, and build. It also had to be cheap.
Thanks to 3D printing, he was able to come up with his own housing and iterate quickly. He wanted to use as many off-the-shelf parts as possible and make it available to more people. And the motor he found in his controller also requires no programming ability. It comes preloaded with the features you need.
He appears to have arrived at a final design that more or less meets all of these needs.
Be sure to check out the complete build process on Instructables. You can also download the files you need.