Grinding Wheel Balancing Fixture/Jig

I couldn't find a good balancing fixture for balancing grinding wheels for my bench grinder and soon to own surface grinder.

Print two sides (same part no mirror, just double on the build plate)
Hardware:
1x 12mm rod
4x 608 skateboard bearings
4x m8x40 bolts.

Pretty simple to setup, two versions, regular and short, short saves printing time and plastic if you want to mount the sides onto a piece of wood. The fit of the bearings needs to be loose, so a file may be needed depending on your printer or print the loose version.