Carl,
I know this is a really old post, but I thought I’d give you my 2 cents… or sense… whichever.
I have been trying to learn Fusion 360 for awhile because it applies to my field way more than Rhino these days, but I’m stubborn and old, so I’ve come up with a very successful work-around for sheet metal in bare-bones Rhino.
Most of my sheet metal parts I order through Oshcut here in UT (they ship, definitely check them out. They’re always on point). What I like about them is they have an extensive materials library with K factors, bend radii, everything you need to know about pretty much any bendable metal.
My workflow now is checking the material thickness I need, looking up the bend radius / radii, then building my parts drawn by lines that are the interior face of the part, then filleting them to the correct bend radius, then offsetting by material thickness, then extruding into a solid. After awhile, if you use enough of the same materials, the radii and offsets become second nature.
It’s a bit tedious, but once you get the hang of it, you can make pretty complex parts with no plugin, no unrolling, no patterning, nothing. Best part is Oshcut lets you upload your part files as .3dm or step and it will run them through their brake software and let you know if you have any collisions or if there’s a problem with the “non-uniform thickness” that can sometimes happen building parts this way. Sometimes I upload just to check that my part is good then send it to a more local-to-me laser cutter / bender that accepts straight up step files and converts everything on their end. Maybe you have someone like that near you?
Again, not ideal or as easy as Fusion (once you get the hang of Fusion), but it IS a possibility, and learning this workflow has helped me tremendously in design / fab.
Hope this helps!!
–Matt
Horick Architectural
SLC,UT