What we do is make the gusset (or whatever flat part we need made) in Solidworks, make a drawing file out of the part on an 8.5in x 11in sheet, print it out on paper, and glue it onto our material (usually lexan or aluminum) with spray adhesive. Then we go to the band saw, drill press, and belt sander and in a few minutes we have our finished piece. If you could cut along the lines with scissors in kindergarten, you can do this easily. We usually use acetone or Goo-Gone to get the paper off of metal parts when we're done.
Here's a Google Doc that I made a while ago describing this process in further detail.
https://docs.google.com/document/d/1...it?usp=sharing
This has worked for us really well. Pretty much all of our custom gussets and plates that don't require crazy precision are made this way. We don't own any fancy CNCs because we spend all of our money replacing our cheap Harbor Freight machines every other year lol.