I was working at a job I didn't particularly liked at the time -- high level software technical support. Very nerve wracking when whole factories are stopped over a software issue. And to decompress and get my mind off of it I bought this little book by a guy named Dave Gingery about making a charcoal furnace. I read it cover to cover, and got hooked. I'd never done machining before, or casting. I built the Gingery lathe, piece by piece, every evening and weekends when I could. It took the best part of a winter. But I learned a huge amount from that.
I also bought all of the other Gingery books, and built many of the lathe accessories. It wasn't a long step to realizing that there were things in common between a lathe and a horizontal mill. They are really the same thing, except you have a Z axis travel. So instead of building the Gingery milling machine, I started to think about how I could convert the lathe to a milling machine. Well it's very easy with this particular lathe because the spindle is so simple and easy to remove. I had already started to make spindles with fixtures cast onto them, rather than screwed onto them. This actually produces extremely precise, repeatable, and stable lathe accessories. When i want to add a faceplate I replace whatever spindle I have in the lathe with the faceplate spindle. Likewise the 3 jaw chuck. And naturally you can make a milling spindle.
Then I though, well as long as I have all these workholding spindles, why not make a lathe type vertical slide milling attachment that can accept those? And to make those slides, why not re-use or modify the same wooden patterns I used to make the lathe slides. And ball handles, etc.
Basically you start to get into interchangeable parts, and you already have the patterns for them! And all the spindle fixtures are interchangeable. Need a rotary table? Use the faceplate spindle. If that isn't quite right for some reason, cast another faceplate using the existing pattern, but with a shorter or thicker spindle, or whatever you need.
So one thing leads to another and all your work is additive -- builds on what you have already done or re-uses parts you already made. So it actually doesn't take as much time as it might seem to someone else looking at it from afar. You've got a library of patterns that can be re-used or quickly modified, and it used to take me about an hour to ram up a mold, run the foundry, pour and cool the part and break it out -- after I had some practice at it. You can do a lot with a small amount of time, and everything you make for tooling makes the next thing easier to make.
My first faceplate was a plumbing flange on a piece of pipe. I trued the face of that, then bolted my newly cast rough real faceplate to it and trued that. Then I replaced the plumbing faceplate with the real one and moved on. A lathe builds itself. And likewise if you follow this method, an entire machine shop can build itself.
I would rate that whole experience as one of the most important in my life. It was a gaining of personal capability. And I think that's what we need more of in these days when we are in danger of becoming helpless consumers, rather than capable individuals.
I apologize for going so far afield on what is really a simple straightforward question. I guess the real answer is, I just found the time, because I got fascinated by something.