eleseur, can you explain your drill motor application?
Andrew, at 1800rpm cruising speed, a car's alternator MIGHT be spinning twice as fast, depending on pulley sizes. I KNOW the pulley shouldn't be hung on a shaft with 18.75:1 gear reduction. Right now Staton has a gearbox with an additional 5:1 reduction shaft, which is a step in the right direction. A 1:1 ratio with back-to-back output shafts would be a much better start, which is what Staton is looking to offer in the near future.
Until then, what I'm looking for is a simple, cheap way to fire up a second-hand alternator. I'd like to run a REAL 12-volt headlight, tailight and brake light to brighten up the night.
How about friction drive with a 1.5" roller and a gravity clutch, like an oversized bicycle dynamo?
Weight is not a problem. At one point, my electric bicycle weighed over 135 pounds.