2020 Aluminum Extrusion
The 2020 aluminum extrusion in the Adafruit shop is 610mm in length. If used as is, the soldering iron will be higher than you might need. I cut mine in half to make two pieces that are roughly 305mm in length. I used a compound miter saw to cut the piece of 2020. I used a titanium blade saw that is graded for cutting soft metals. I made sure to clamp it down to the support base while cutting.
Get the parts ready to assemble the platform. I used a piece of pine wood that measures to about 19cm x 25cm (7.5x10in) and 1.7cm(0.65in) thick. I suggest using M3 (#4-40) wood screws to secure the 2020 bracket to the platform.
Install 2020 Bracket
Grab the piece of 2020 and fit the bracket over it with the tabs. Make sure they are flush with the bottom. Use two M4 x 8mm button head screws and slim t-nuts to secure the bracket to the 2020.
Mount Holes in Base
Place the bracket over the platform and decide where you want to mount it. I choose to place it centered over to one side. Use a pencil to trace the mounting holes onto the wood. Use a drill or rotary tool to make pilot holes (use a drill bit smaller than the screw).