Assembly is underway to integrate Polaris, a rover for exploring lunar ice. The appended CAD illustrates the Polaris chassis with transparent carbon tubes to show internal structures. Mechanical assemblies add structure to the carbon fiber chassis tubes for mounting rocker arms and passive averaging mechanism.
Four shoulder joint assemblies are match-drilled to the side beams to ensure alignment. Each shoulder joint has a main shaft that supports a rocker arm and is chained together with the adjacent shoulder so that rocker arms on each side of the rover rotate together. The passive averaging is accomplished by linking the chain from each side beam together through a torque tube that goes under and over the chain loop on each side of the rover, respectively. This configuration combines the directional tensile strength of the carbon fiber beams with the general strength of the aluminum assemblies, resulting in a light and rigid chassis.
In addition to constructing the shoulder assemblies, the integration process also entails fitting up the carbon fiber mid beam, aluminum radiator plate, and baseplate. These parts are added through a combination of machine screws, pop rivets, and structural epoxy to ultimately create stiffness between the carbon tubes, forming the main structure of the ‘H’ shaped chassis.
One-hundred-twenty-four parts along with the carbon tubes will be assembled over the next month, followed by integration of electronics and actuators that will get Polaris driving soon.