Well, an old knee mill like any of those are great if you want a hobby and are interested in electronics. However, if you are wanting to make chips, I'd hold out for a VMC. They are going for peanuts right now. By the time you finish a retrofit (which would be inevitable), you'd have a LOT of time into it, and you'll have spent just as much money. A friend of mine did a retrofit on a 40-taper knee mill. It goes through material pretty quickly, and he said he spends a lot of time sweeping up chips, cleaning splashed coolant, etc... The knee mills are good if you are only making occasional parts for a project here and there. But if you plan on doing any amount of machining, a VMC is certainly the way to go. Keep an eye out. I just saw a nice one (in perfect running condition) go on fleaBay for $4K.