Summary

A battle bot chassis that uses the PCB, motors and nuts and bolts from the Smartibot kit plus a 1:220 gear ratio motor for the flipper. It uses a 16mm marble (included in the Smartibot kit) as the castor wheel and 43.2 x 22 mm LEGO tyres (44309) and these wheels:
https://www.thingiverse.com/thing:6080836

Should print without support with the rear shell back-side-down, the motor mount front-side-down, the two halves of the scoop on their sides and the front shell upright.