A new machine

I've had to do some adjusting to my machine. I wanted to lengthen the stroke so I remounted the crank arm farther out on the wheel. This exaggerated a small flaw in my engineering into a large one . The bottom of the see-saw actually moves in a circular path. Like a child on a swing. This flaw was pointed out to me by friends. So I had to add a universal joint at the bottom of the see-saw. This allows the system to move smoother. And it allowed the overall stroke to reach 4 3/4 inches. Which will suffice. It's still only powered by a drill.