This works really well but is some what of a pain to mount. Took my around 2 hours to mount after all parts where finished printing.
If you are doing this mods heres my tips:
1) Make sure that the nuts are stuck to the wheels. Superglue them, burn the nuts with a lighter, superglue them again. If the nuts come loose you are screwed.
2) Make sure you print different z-spacers in different height.
3) Make sure that you have the M2x25mm.
PrimaCreator P120 aka Monoprice Select Mini