I decided to recreate mechanical motion number 91, from 507 Mechanical Movements. This is described by the site as a “Triangular eccentric, giving an intermittent reciprocating rectilinear motion, used in France for the valve motion of steam engines.” You can find an animated original on the site here, to give you an idea of what “intermittent reciprocating rectilinear motion” is.

To recreate this, I started by downloading an image from the animation and loading it into Adobe Illustrator and using the ‘image trace’ function to create a vector overlay of the image.

I then used a composite of a circle and a vector path to trace over the cam, since the original trace was very jagged and inconsistent, especially where it lined up with the edge of the box.

I then trimmed the large circle where I didn’t want it and added the smaller circles for pivot attachment.

Finally, I added some sort of basic attachment points to the ends of the frame, gave it consistent coloring, and cleaned up anything that needed it.

The final image should work reasonably well, but I fully expect the pushing motion of the cam to not be as smooth as it could be, since the parabolic section of the cam is traced by hand, not described by anything mathematical. I also doubt that the cam will fit perfectly inside the hole in the frame; I expect that as it rotates, there will be either gaps that appear or the cam will not fit inside. However, I feel reasonably satisfied with this image, and would be interested to see if it works.