current slip rings usually use sliding brushes to carry current. These wear out and eventually have to be replaced. There's also some that use liquid conductors like mercury or indium gallium eutectic alloys though those are typically more expensive.

I propose using a thin circular metal band similar to the balls in a ball bearing but deformable. it would roll between the rotating and stationary elements of the slip ring but because it deforms it would form a larger contact area with the rotating and stationary conductors than a rigid roller would.

if the stator, rotor and band are serated then multiple bands can be used without coming in contact with one another as the serated band acts somewhat like a flexible gear.
-- RichardT, Dec 10 2010

Look up metal fatigue.
-- MechE, Dec 10 2010


That's why you use a thin metal band made of a material like beryllium copper
-- RichardT, Dec 10 2010


Many metals have a definite threshold strain below which they don't fatigue, [MechE], however often the strain is repeated.

Think of the reeds of a harmonica, if you must.
-- MaxwellBuchanan, Dec 10 2010


[+] Anything with Rolamite (or in this case, a scrollerwheel) gets a bun from me.

Of course, the question remains of whether spring copper will fatigue faster or slower than sliding brushes will wear out.

In addition, even if the metal band of a scrollerwheel is more long lasting than the brushes of a conventional slip ring, there is the additional consideration of replacement cost and toxicity.

Carbon brushes are cheap, nontoxic, and easy to replace.

All beryllium compounds are toxic, which increases cost of manufacture, and replacing the band in a scrollerwheel bearing likely requires a fair amount of dexterity.
-- goldbb, Oct 14 2011


Spring copper fatigues very quickly if worked for long periods at a time. It's really more of a 'repeated use' material, rather than a 'continual use' one.
-- Alterother, Oct 14 2011



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