The basic LoCoRo chassis needs to secure the wheels or treads, the drive motors, and the electronics.
There are many options for the chassis.
The tricycle chassis use two drive wheels and a small free wheeling caster for the front. The system used differential drive - similar to how a zero-radius lawnmower drives. There are kits available with polycarbonate or metal frames and a DIY solution may be built with almost any parts available. Wheels can be purchased, cut out of available materials, or 3D printed. Wide plastic jar lids - like those from peanut butter jars - make great wheels.
The tank chassis use a left and right drive sprocket and treads. This system also uses differential drive. RC tank kits are available and a DIY solution may be built using small timing belts for treads. When using RC kits, the DC motors will require electronic speed controllers.
A customer chassis may be constructed from a wide range of materials. They may also be designed and 3D printed.
Chassis typically use an even number of drive motors with half used on the left and half used on the right. A differential drive system is the easiest to build.
A mecanum wheel system requires four drive motors - one per wheel. The mecanum wheel has rollers which are ±45 degrees to the wheel's axle. Two wheels have the rollers at +45 degrees and two wheels have the rollers at -45 degrees. Mecanum wheels allow the chassis to move like a tank and also to move laterally. Unlike the simple wheel, where each wheel is a single print, each mecanum wheel is a collection of printed parts and fabrication. More details on the printing and assembly are covered in the section on 3D printed parts.