I have yet to see any mechanical nightmare...and believe me, there have been thousands throughout the Industrial Age, that put out more power than it used. I doubt your examples will stand up against examination any more than anyone else's did. When I was in college, the Dean Drive was the big thing.

In my field, I get e-mails from people who claim to have the Next Great Thing for space travel, usually some form of reactionless drive, or anti-gravity. The jury is still out on ionic manipulation of the atmosphere, but I've only seen it work on featherweight "flying bedspring" prototypes.

Oh, we could go over all the math, the science, the conservation of energy bit, and all the rest.

But tell ya what, let's just pull out our "inner cracker barrel guy" and listen to him.

If somebody ever comes up with something that really works, he'll build a pile of them and get filthy rich. Unless it requires sixty pounds of pure platinum to run it, the money to build working prototypes for perpetual motion machines or cheap antigravity devices can be found, and without begging for it from suckers.