Here is the granddaddy 24 shell nested screw I 3D printed on my trusty Type A Machine Series 1 2013. I made the model with a parametric tool I made in grasshopper to make nested screws. The number of leads, radius, offset and number of shells are the parameters. Check out the script my friend Henner made to do something similar here: https://github.com/hzeller/gcode-multi-shell-extrude
