I built one. I got the basic concept from a 2 inch square picture in an owners manual of a JD snowblower. I copied the idea, assuming I understood it. I thought the cable system amplified the cylinder range about two to one. Actually it amplifies it three to one. Happy mistake, I got more range than I had planned for. I found some pictures of it all. Some of the more exotic parts were made on my nc plasma cutter. The pulley wheels came out of McMaster Carr. The cable was just some locally-sourced vinyl coated stuff. I took bolts, cut off the heads, bored into the shank, and silver soldered the cable into them for ends (see pics). If questions, please ask.