I'm working on a few of these kinds of projects and progress is highly variable. Some days, I might only get a few lines of code done. Hardly enough to make a

I'm working on a few of these kinds of projects and progress is highly variable. Some days, I might only get a few lines of code done. Hardly enough to make a difference but then other nights, in maybe the same amount time, I'll build out some massive subsystem. I think big progress will eat up an evening but I think the important point is that it's not a job -- so when it eats up an evening it should be fun and when you've not other important/interesting things to do. I almost never know when I'm going to make progress when I start.