5
Connect them with gears and they will run at the same speed - any sensor / control will have an accuracy range
2
You want something called a gearmotor, which is a modestly-sized DC motor that can run in either direction at a variety of speeds, depending on the voltage you feed it. You select the appropriate gear ratio to yield the RPM you want. See the Marlin P. Jones & Associates on-line catalog for a good selection of inexpensive gearmotors.
Also note that it is ...
Only top voted, non community-wiki answers of a minimum length are eligible
Related Tags
motors × 370mechanical-engineering × 122
electrical-engineering × 97
torque × 66
gears × 37
power × 21
automotive-engineering × 20
control-engineering × 19
stepper-motor × 17
design × 16
servo × 13
electric-vehicles × 12
bearings × 10
electrical × 10
pid-control × 8
robotics × 8
mechanisms × 7
electromagnetism × 6
pulleys × 6
actuator × 6
current × 6
linear-motors × 6
thermodynamics × 5
applied-mechanics × 5
pumps × 5