So I could have sworn I saw a machine similar to the style of the workhorse one but on the back and there was like a rubber round cylinder that was next to a similar next to an elliptical cylinder the elliptical causing the back and fourth motion. Im curious to designs like this because it seems at least in my head as if this could change the stoke profile and could enable a person to create machine that is not quite 50 50 duty. It also seems like the rubber cylinders could act as a dampening mechanism. Did I see this or should i build it?