That's one thing I designed for my Anet A8. I attached this corner protector to the base plate. My base plate is made of wood and 15mm thick.

Facts about the thing:
40x40mm edge coverage with 15mm board thickness
42x42x19mm total external dimensions
Countersunk hole 3mm for fastening with screw on the underside.

Hope it is useful.
Hope you like it. :)