I just took my mecanum rover for its first outside drive.
Axles are taken from this:
Controller is a Mateksys F405-STD with a Mateksys 3-6s (9-27V) PDB. The rover runs on 2s, but the PDB is working without a problem.
A Raspi W zero is used as a companion computer, running mavlink-router and motion, but it is too slow to be useful. I will replace it with a RPi 3B+ soon.