Couple people on the net; as I am sure you've seen, have tried it. All straight arm designs. I guess things like transfer function of materials and such would play the biggest part. I once spoke to the guy who owned Hammer Dynamics and he said he built his out of a No.2 pencil; suspended by a rubber band from a simple scaffold. As the arm arced acrross the record the rubber band would twist and apply anti-skate; or counter-rotational force. It was stabilised in the horizontal plane by an eye-hook tied to a massive teflon sleeve floating in a bath of silicon. Actually; may be too much work now that I think about it. The bearing on the Technics arm seems pretty close tolerance.