Although I know other people have built lathes themselves, after an enormous amount of looking on Google, I saw most homemade lathes involve casting and milling, as well as using off the shelf components like chucks and tapers. Being only a high school student, I wanted to experiment with a lathe without having to spend hundreds of dollars that I don't have. I ended up using almost all scrap materials from my basement, so there is no need to follow my materials choices. Because your design choices will vary, this article is more of a record of how I built this one, rather than a manual for building yours.
I managed to build this lathe in about a week, with not much more than a cordless drill, a drill press, a jigsaw, and assorted hand tools. I hope that I have documented my project here in an understandable way.
Warning: This is a powerful device designed to spin stuff quickly. I take no responsibility for anything you do. Don't try this unless you have at least a little bit of experience with tools. And wear safety glasses when using it because particles fly around.
Step 1: Decisions
So, if you are reading this, you must be interested in building a homemade lathe. First, I would advise you to look at the diagram in the [http://en.wikipedia.org/wiki/Lathe_(tool) Wikipedia article] to learn the basic parts of a lathe.
The first thing you have to decide is what kind of lathe you want. Either to work with metal or wood. A wood lathe requires a less powerful motor and not as close tolerances. Also a wood lathe does not need the complicated tool rest that a metal lathe has. For the first version of my lathe, I decided to just stick with wood and see if I could come up with something that actually worked.
The next thing to decide is size. I would highly recommend not going too overboard... tree size logs on a wood lathe and 50 pound steel bars on a metal lathe are best left to professionals I think. I decided to try to make a wood lathe for pieces up to 4 inches in diameter and about 30 inches long, although I will not be trying something that big until I get more practice with small items, like tops, chess pieces, other little toys. But I figured that I had a pretty powerful motor sitting around, so I might as well make it big enough to handle large salt shakers and chair legs so in the future I could do large things.