How do locker combinations work

They fit on a shaft molded into the back of the lock with a spring pressing the stack of cams together when the lock is assembled. The spring provides friction between the cams to hold them in place. The purpose of the cams is to control a latch that engages the end of the lock's hasp. The cams each have an indentation in them.

When the indentations align properly the latch is able to fit into the indentations and release the hasp:. If you have used a combination lock before you know the drill: "Turn the dial clockwise two full rotations to the first number of the combination.

Then turn it counter-clockwise past the first number to the second number. Then turn the dial clockwise to the third number and the lock will open. Turning the dial 2 full revolutions gets the teeth of all three cams engaged, so the three cams are turning in unison. Now when you turn counter-clockwise only the top cam is rotating. As you go past the first number, the first cam's tooth engages the second cam, so now the two cams are moving.

The friction provided by the spring, however, keeps the third cam in its position. When you turn the dial clockwise again, only the top cam rotates. Once all three indentations are aligned properly by this process, the lock opens.

Then, turn the dial to the right and stop at the first number in your combination. After you have stopped at your first number, turn the dial to the left past "0" and stop on your second number. Finally, turn the dial to the right and go directly to the last number. You should now be able to open your locker by pulling the latch or opening the lock. To learn how to open your locker if you don't have the combination, scroll down!

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Method 1. Spin the dial at least three times to the right clockwise , all the way around. This "clears" the lock of any previous numbers.

If at any point in putting in your combination you mess up, do this again to start over. Enter your combination. Turn the dial to the right and stop at your first number. Always start with a turn to the right! Then stop at your second number. Some locks are a bit odd or finicky -- if your locker isn't opening after you put the three numbers in correctly, try turning left past your second number once and stopping on it on the next go around.

For your third number, turn the dial to the right and go directly to the last number. Leave your lock on this number. Always remember: right, left, right. Open the lock. Pull the lock open and out of the hole, or pull the latch or handle, if there is one.

Otherwise, tug on the knob to open the locker. If your locker just won't open, try it again with the last number being five before or after your "official" last number. Sometimes the older locks get, the shakier they get in their requirements or abilities.

If that doesn't work, ask your classmates or teacher if there are any similar quirks in the school locker system. The typical combination lock has a combination dial that is attached to a spindle. Inside the lock, the spindle runs through several wheels and a drive cam.

The number of wheels in a wheel pack is determined by how many numbers are in the combination - one wheel for each number. When you turn the dial, the spindle turns the drive cam. Attached to the drive cam is a drive pin. As the cam turns, the drive pin eventually makes contact with a small tab on the adjacent wheel called the wheel fly. Each wheel has a wheel fly on each of its sides. The drive pin spins the first wheel until it makes contact with the wheel adjacent to it.

This continues until all the wheels are spinning. This is known as picking up the wheels. Each wheel on the spindle has a notch cut into it. When the right combination is dialed, all the wheels and their notches line up perfectly.