I've been working on vertical systems for more than 2 years and mainly adjustable stroke vertical systems. I had the same idea for the drive system with the exception that I had envisioned 3 smaller channels for 3 strokes. Never made it as I don't have a 4th axis cnc . Nice to see this mechanism come to life. To change the stroke on this Stigma Amen, you would have to replace the white piece. That green one seems to contain a new motor option. Pretty cool.