Here one can find bottom plates for some FPGA development boards, all holes are made for a 2.5M 4mm screw.
Mimas v2
mimas_v2_bottom_plate_01.stl.zip
EP2C5 Mini Board (CycloneII EP2C5T144) FPGA Development Board
ep2c5_mini_board_bottom_plate_01.stl.zip
Mojo Board
mojo_bottom_plate_01.zip
These 3D-object were designed by Wolfgang Spahn 2016.
They are licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.