Just my 2 cents !! Being a tool collector, I have several treddle powered machines from the late 1800's and early 1900's. One being a Roger's from around 1915. Very ornate to look at, but a real beast to do any type of precise work with. It has both scroll saw and lathe operations. If you are not inclined to put in a lot of time to make a very precise machine, I would not suggest taking on this task. You can go to Harbor Freight and buy a mid size VS lathe for around $100, plug it in, and see if you like turning or not. It's the add ons ( chucks, drill bits, turning tools, etc. that are going to raise the price of turning things no matter what you buy or make. I have built several mini lathes in the past to make items for doll houses, and they work fine for very small pieces, powered by drill motors and Dremal tools. It's hard enough consentraiting on turning with your tools, and not having to work your feet and legs trying to maintain a constant speed. It's nice to go back to the old ways of doing things the way they did in the past, but unless you over design and build, I don't think you will be happy with the results. It usualy takes a lot of sanding to make a nice piece. Been there, done that !! There is, however, nothing like a powerless workshop, with only the sound of your hand tools cutting into wood, to give you pride in the work you are doing !!! Just my view. Jim S