Being a mechanical engineering novice (I stick closer to solid state electronics), when I look inside of any toy-grade RC car, I see a series of different-sized gears between the motor shaft and the drive axle.
- Why does a single-speed RC car require a gearbox?
- Instead, why can't a gear on the motor shaft connect to a gear on the axle?
So far, two of the plausible explanations I have come up with are that
- The motor turns at a different RPM than desired by the axle, thus conversion is required.
- To put protection between the spinning of the axle and the spinning of the motor.
I ask because I am setting out to make my own Lego car driven by a DC brush motor and have no idea what to do for a single speed gearbox other than hook one gear to the motor shaft and one gear to the axle and let it go.