I suspect the "j" in jgro represents his name, John. You can see pics of his Generation I and Generation II CNC machines and other projects on his website,
John's Shop Pages. Be sure to check out the extensive links on his links page!
The $6.00 jigsaw/scrollsaw made from an old sewing machine, some scrap lumber, and miscellaneous hardware is also an impressive little DIY project.
Enjoy!,
HayTay