Vibratory tumblers

No need to build one, Harbor Freight sells two sizes of perfectly useable ones cheap.

I've seen a plastic bucket siliconed to the cone of a larger woofer, face up, and hooked to the shop 100-watt stereo. filled with walnut hulls or similar, sometimes with liquid for a sort of (non-ultra)sonic cleaner Efficiency dependent on choice of music.

I made one from a 20 lb propane tank & treadmill motor:

Works well, but is VERY loud.

Bob

Ina God da da vida would be a great tune.....

Gunner

"First Law of Leftist Debate The more you present a leftist with factual evidence that is counter to his preconceived world view and the more difficult it becomes for him to refute it without losing face the chance of him calling you a racist, bigot, homophobe approaches infinity.

This is despite the thread you are in having not mentioned race or sexual preference in any way that is relevant to the subject." Grey Ghost