Notes on this design:
- The location of the motor is quite flexible.
- You can use a 8t gear instead of a 24t.
- If it doesn't switch quite right, you might try adjusting:
- The position of the stop pin on the 40t gear
- The position of the switch, by adjusting the number of bricks/plates between it and the red bricks.
- Advantages of this design:
- Uses few parts.
- Uses no relatively rare parts.
- Can be built onto any spare beam in your robot (the motor can be placed on the side of the beam instead of the end).
- Switches rapidly, even on old stiff pneumatic switches.
- If you are concerned about damaging the motor, you could:
- Replace the 24t gear with a white "clutch" gear.
- Use the RCX to run the motor at low power for the last part of its travel.