I loved that set. The differential was a magical thing to 7 year old me. I rigged up a handbrake using two rack gears that squeezed a gear on the end of the dri

I loved that set. The differential was a magical thing to 7 year old me. I rigged up a handbrake using two rack gears that squeezed a gear on the end of the drive shaft. It definitely spurred my interest in engineering.