Inspired by u/Consistent_Text_5466 who used a modified milk crate to build a universal rack for backpacks.
I riveted the frame together out of aluminum angle and aluminum metal. The rack is quick detachable without tools, and is secured with four 3D printed PETG clips.
I ended up lining the inside faces with thick sheet foam to cover sharp edges on the bolts that secure the mounting clips to the frame.
After several tweaks, It’s finally sturdy enough for a heavy bag, and rigid enough to not rattle over bumps.
by bcl15005