Have a wheel (with no torque) on a strut, connect the strut to the motor. If the motor is facing up, the wheel will spin. If the motor is facing the side, it will not spin. Open the craft, select a wheel (just so you can tell it's actually spinning), and set throttle to 1. Use Slider 1 to rotate the motors outwarads. the wheel will spin as long as slider 1 is not below -0.33. If you go lower than this, the wheels stop spinning.
