There has been talk of testing this, but as far as I know there hasn’t been anything done yet. I believe @mrfugu has plans to do this with his unistrut frame. As far as mechanical engineers, I know that quite a few people on these forums have quite extensive knowledge into the mechanical workings of the machine. See @dlang’s post above mine, he is very good with this sort of thing.
My sculpture degree doesn’t really give me much formal background in engineering, but I do have a bit of relevant work experience. Still doesn’t make me an ME though. If I could tell high school age me what to major in, I would have guided myself in that direction.
This is a good point. My sled is somewhere around the 40 lb mark and I haven’t run into any issues with the motors stalling. I need to more accurately measure its weight at some point, my current numbers come from adding together the weights of all the components. I have been wondering if I’m putting too much stress on the motors, though.