I searched the Thingiverse to no avail. Are there any 3D printing enthusiasts out there?
Many of us have an old PC with an ATX case in the closet or garage. Then we drool over some new ARM board and buy it, which oftentimes has no case. What if a 3D-printable adapter plate was available (as an STL file) on Thingiverse, which, when printed, is the size of a normal ATX motherboard, (having mounting holes in all the normal places), then it also has holes (possibly raised a bit, in a standoff-like way) in carefully chosen places that correspond to the mounting holes for many of the common ARM boards out there (which are not the size of a standard Raspberry Pi)?
This would let you easily mount any ARM board (or even maybe 2 or 3 ARM boards) in an ATX case. This adapter plate would be the thing between the ARM board(s), and the ATX mounting holes (for an ATX motherboard) in the ATX case.
I have no 3D printer myself, and am a total non-expert in 3D CAD design. I have no clue where to start, and I'm in Linux.