I have a Little Ark grain grinder with both the stone and steel burrs, that I have used for over 15 years. About 2 years ago, I tore my left shoulder tendon and several of the muscles in that upper arm. It took over a year to heal to where I can do most everything with it, but the strength is not full yet. As a result of not being able to use that arm, I kept trying to do everything with my right and strained that one a wee bit. So grinding has not been my favorite thing to do lately.
When I saw that trailer from the New We DVD that another poster put up, my eye caught on a woman using a recumbent bike type contraption to pedal a washer of sorts, which made me think very hard about using a bike to attach to the Little Ark flywheel to grind my grain. This is what I have.
http://www.retsel.com/little-ark.html Today I found a link to MayaPedal and they have a model with plans for a bike grinder that you can download in pdf, in case anyone is also interested. I really like the idea of the recumbent so I can read my reference
books at the same time and possibly be able to hook it up to a washer as well.
http://www.mayapedal.org/Mill.pdf They also have other plans
http://www.mayapedal.org/machines.html