totally out of my expertise..You don't need any fancy programming skills.
- Install the OpenSCAD software.
- Run the OpenSCAD program.
- Highlight/copy/paste the 156 lines of code from reply #24 into OpenSCAD.
- Save the file. I used the filename "Hub and Bat - Bat Controller.scad".
- Press F5 to generate a preview of the part.
- Right click + drag to slide the view of the part. (no rotation)
- Left-click + drag to rotate the view of the part.
- Scroll wheel to zoom the view in/out.
Right now, the baseball bat is 75mm/3" long and the barrel (fat part you hit the ball with) is 12mm diameter. (12.7mm = 1/2")
Do the shapes and proportions look good to you?
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Code for the cam is almost done.
- Had to increase the cam radius from 26mm to 33mm so there's just enough room for the shaft collar hub, bumper notches, and the mounting block for the spring screw.
- The increased cam radius changes the amount of spring stretch from 80mm to 104mm.
- This should still be within a reasonable range of stretch and tension for the spring.

Scott