This is a small sample rover using Mecanum wheels generated by my Parametric Mecanum Wheel generator tool. The goal was to have the mechanical components be 100% from-scratch as a design and learning exercise. For a more complete writeup of the project, BOM and assembly process, check out this blog post.
It works pretty well on carpet, but printed from hard plastic, doesn't have enough weight and friction to drive sideways reliably on hard surfaces. The itty-bitty wheel bearings collect hair like crazy.
The electronics are held in a "printed protoboard:" a frame into which female headers are glued to provide a pluggable holder for each carrier board. The electronics consist of a LPCXpresso board with an LPC1769 (Strictly because I wanted to play with ARM, the processing power isn't needed), two Pololu TB6612FNG dual motor drivers, a Pololu D24V10F5 5V regulator, and an Adafruit Bluefruit Bluetooth serial module. All the wiring is soldered to the female headers.
The most current source code for the SCAD objects, LPC1769 firmware, and PC software to drive it with a game controller are on github.
This was made from scratch, but it owes a lot to the awesome Mecanum Wheel Rover 2 by Madox. Specifically inspired by that project are: similar general dimensions, seven rollers per wheel, and use of MR63ZZ bearings.
The frame body, spacers and electronics holder are printed in ABS. The electronics cover was printed with clear PET+, which stuck to the PEI print bed much too strongly and cracked in several places when removed. That part was put back together with superglue.