operation cnc

[asbo]

I think I'd put a T-nut(red) in the bottom of the top extrusion and then drill a hole up through the bottom extrusion and bolt(blue) them together.
See my super accurate diagram :D


maybe you'd also want a piece of plate along the back bolted to both pieces of extrusion. I'm no expert though.

Also I'm surprised by their lack of response, they sent me some free design software before I even bought anything. I just used the Contact Us form on their web page.