@e4d Sorry, It's been a while and I don't have that on my latest laptop. I'll give a search on my home server when I get a chance to see if I may have backed it up.
But, give a look at the caribou github - variants from duet 2 and 3mini exist.
https://github.com/Caribou3d/CaribouCartesian/tree/master/STL/01_full-kits/Frame/Duet

Hope that helps!