Personally, I'm also a hands on guy, I prefer playing one-on-one...I've seen hundreds of fucking machines, drill-dos, and various other toys, and never really bought into the concept. It definitely fits better in a hardcore BDSM scene than in a medical exam...but at the same time, I can't say I find it 'disgusting'...and keep in mind that most normal people find the idea of sticking a hose up their ass and filling themselves with water 'disgusting' - it all comes down to whatever gets you off. If you're the kind of person who loves being assaulted by a mechanical one-eyed trouser frog (thanks Anne, love that term), then, well, go for it.
[quote author=DrJ58 link=topic=25742.msg245787#msg245787 date=1253836451]
...I suggest the best choice would be electrical power, rather than steam...
[/quote]
OMFG a steam powered fucking machine - this would be AWESOME!!!!
As far as building one goes, you need a decently powerful electric motor (.5 hp might be enough, but 1hp is probably better), some metal, a welder, a guy who knows how to use the welder and won't be pissed at what you are up to, and time. The design of these things is quite simple, though I suppose, with some ingenuity, you could build one that had variable pitch, vertical/horizontal oscillation, stroke depth, and probably even one which twisted.....hit the drawing boards and let us know what you come up with....