1st robot is built from dvd drive and harddrive tray for the body, has H-bridge built from relays sourced from old UPS, motors and wheels from printers. It also has an mp3 player and ultrasonics that I bought, but all the moving parts and chassis are from repurposed tech.
2nd robot uses an old power tool battery case as chassis, with bought L298M h-bridges
Both run on arduino, the 1st an UNO, the 2nd a nano.
Both use former printer rollers for wheels, both use old ir recievers for remote control and are controlled by old TV remotes.