Car with Motor that spins lego/Technic Driveshaft + Transmission

[Jgore21]

Dear Raspberry Pi Community,

I want to build a Pi Car that uses a motor to spin a driveshaft and use servos to change gears and turn the front wheels. This is different from other projects I've seen because others use a motor that powers each wheel independently but this one would drive the back wheels via the driveshaft to a gearbox to the differential.

I need help understanding how to choose the motors to use for each part of the build as well as what else the circuit needs in order to power them. Do I need specific Hats or Relays? What power supply should I use?

Description of each Motor's task:
A) 1 motor (Motor A) that has reasonable RPM and torque for a small car would fit easily into a shoebox
B) 2 or 3 Servo motors to change gears, turn front wheels, apply brakes

I don't know what Motor A would even be called so I could look for it online. Could I use a Drone Propeller motor?
The servo motors make sense to me but would any servo work?

I hope someone understands my car idea and can help point me in the right direction!

[Imperf3kt]

YouTube has a ton of videos on this matter, just without the Pi. But that's easily fixed.

But just for the sake of it, why?

People usually drive each wheel with one motor because it is far more efficient and you get more power out of the car. A drive train system has frictional losses and you'll need four times as much torque to achieve a comparable output power

[IanS]

A drone motor is a high speed brushless design, which has only a moderate amount of resistance to overcome (i.e. spinning the prop through the air). This means they are designed for high speed low torque operation. You want much higher torque, but only low to moderate speeds. You should probably look for a normal DC motor with an integrated gearbox. You might decide to use 6cm diameter wheels (18.8cm circumference) and hope for a speed of about 1m/s, which would need about 5 rps, so 300rpm. No small DC motor will run this slowly without having a gearbox on the front. The corresponding advantage is that the gearbox also increases the torque, so that the vehicle will actually move rather than stall the motor.

There are a number of different motor types, and plenty of tutorials on-line that explain the different types and use-cases. In summary:
Brushed DC motors: more volts = more speed, until you burn out the motor at least.
Brushless DC motors: generally very high speed, and need a separate ESC (Electronic Speed Controller) to run them.
Servo motors: Only move through a restricted range (unless 'continuous') but good for acurate positioning. Might be good for gear lever control.
Stepper motors: Need a driver board again. Moves in steps, hence the name. Good for accurate positioning over a longer range than servos.