Whether you assembled your ergodox wrong or intentionally omitted the plate, you may still want the ability to use stabilizers for the 2u keys on each side. This model started by cutting out the appropriate area from Diomedia_be's design and then tweaking it until my plate-mount stabilizers fit and were in the correct position. There's a bit of a chamfer to clear small solder bumps from through-hole diodes as well.
Should print on just about any 3d printer without support.
Why would I assemble my ergodox wrong on purpose, though? Well, using pcb-mount switches gives enough stability for most of the switch positions without needing a plate, I thought a bare PCB might look cool, and I plan to tinker with this one a lot... e.g. adding new electronics like an LCD, writing my own firmware.
UPDATE: Apparently 0.5mm makes a huge difference in whether or not a stabilizer binds up when you push a key down. Uploaded a new version 6 of the files to address this issue.