LEGO MINDSTORMS Robot Inventor
Combination Lock Claw
The red ball is locked in a pair of claws protected by a combination lock. Turn the dial to enter the combination to unlock the claws and retrieve the ball.
Two programs are provided. The simpler program only requires you to enter a single digit code number from 0-9 to unlock the claw. The more advanced program allows you to set your own combination to a series of any number of digits, and then you must enter that combination and get all of the digits correct to unlock the claws.
Building Instructions
Combination Lock Claw
Using the Combo Lock 1 Program
The simpler Combo Lock 1 program will start by locking the claw right away. To unlock it, turn the dial to the correct single-digit code in the program (see the program -- you can change it there if you want), and then press the right arrow button on the hub to unlock it. You can re-lock it with the left arrow button.
Using the Combo Lock Program
The Combo Lock program starts by briefly displaying "..." and setting the center hub button to yellow to prompt you to set your own combination. Your combination can be any number of digits (each digit is 0-9). Enter your combination by turning the dialand pressing the right arrow button on the hub after each digit. When you are done, press the left arrow button to lock it.
Once locked, you can enter a combination by turning the dial and pressing the right arrow button after each digit. When you are done, press the left arrow button. The lock will open if you got the combination right, otherwise you can keep trying.
After successfully opening the lock, you can either re-lock it by pressing the left arrow button (then the same combination will open it again), or you can press the right arrow button to set a new combination like at the start of the program.
The center button on the hub will, of course, end the program, which makes the lock manually openable or allows you to start over if you forget your combination. Of course, this is not secure like a real lock, but it can't be prevented.