This video and tutorial takes you through making a wooden lock out of a single 2x4.
Clear plastic (if you want a see-through lock)
Step 1: Cutting the Block
The piece of 2x4 used for this build needs to be 6 inches long for a final dimension of 6x3.5x1.5 inches. I used a jointer, planer, and table saw to square up all the edges making my 2x4 slightly smaller than stock. Squaring up the 2x4 is nice, but it is not necessary for this project.
Step 2: Cutting the Front and Back Plate
Set the fence of the bandsaw 1/4 of an inch from the blade and run the 2x4 through removing the front and back faces. Once the two cuts are made you will be left with the centre 1 inch section as shown in the image.
Step 3: Cutting the Internal Parts of the Lock
Cut the centre piece into 7 sections. This will allow for three pins to slide up and down and four structural sections that will act as walls for the pin chambers. Because the 2x4 is 3.5 inches across, make each cut 1/2 inch wide. I set the blade on the left side of the 1/2 inch mark so that the kerf of the blade is taken from the piece. This blade placement ensures you don't end up with a skinnier last piece. Losing the kerf of the blade (and thus having the width slightly less than 1/2 inch) also gives the pins room to move once the lock is assembled.
Step 4: Label the Cut Centre Sections 1-7
Step 5: Separate Out Sections 1,3,5,7 and Mark for the Key and Deadbolt.
After separating out pieces 1,3,5,7, mark out the slot that the deadbolt will ride in. The bottom of the deadbolt is 1.5 inches from the bottom and the deadbolt is 1 inch wide, so make marks at 1.5 and 2.5 inches and finish the lines with a square. Then mark out the slot where the key will go. This is similar to the deadbolt slot but it will only be cut on pieces 3,5, and 7. Make the additional marks for the key slot at 3.5 and 4.5 inches and again, finish the lines using a square.
Step 6: Mark the Slots for the Key and Deadbolt on Pieces 2,4,6.
Mark out a line at 3/8ths of an inch from the bottom of the pins. This is where the pins will fall into slots on the deadbolt. Then mark out the slot for the key at 1 3/8 and 2 3/8 inches (or 1 and 2 inches above the 3/8ths line). You can use #7 as a story stick to mark out the width of the key slot. Using the #7 as a story stick is not necessary, but it sometimes in woodworking it is more important to have to pieces be identical than to have them a particular precise measurement.
Step 7: Remove the Material for the Key and the Deadbolt
After marking the pieces, tape them together to accuracy when removing material. I set the height of my blade to 5/8 of an inch and removed the material on my table saw sled. You could use a mitre gauge or the bandsaw as well.
Step 8: Glue Pieces 1,3,5,7
Make sure 1 and 7 are at each edge of the back panel and space 3 and 5 at even intervals in the centre.
Step 9: Cut the Final Length of the Pins.
I chose to cut the pins 1/4 inch shorter than the top of the lock. This top measurement is taken when the keyhole slots in the pins are lined up with the slots in pieces 1,3,5,7.
Step 10: Cut and Mark the Deadbolt
Use the scraps of the 2x4 to cut out a 5/8x1inch deadbolt and place it in the lock to mark out the slots for the pins to fall into. I let the deadbolt stick out 1 inch past the left side of the lock. The slots will end up being just under 1/2 inch wide and 3/8ths of an inch deep.
Step 11: Cut Pin Slots in the Deadbolt on the Bandsaw
Cut deadbolt slots out on the bandsaw. You could also use the table saw technique shown earlier, just lower the blade to 3/8ths of an inch.
Step 12: Mark Out the Key
Mark out and cut the key in the same way as the deadbolt. It is important that you have the key touching the end, or left side of the lock so that the slots lines up correctly
Step 13: Make Sure the Key Slots Align Properly
Use sandpaper to fine tune the alignment.
Step 14: Glue a Stopblock on the Deadbolt
Make sure the pins are set in the deadbolt to get the alignment right. The deadbolt in this lock sticks out 1 inch from the left side of the lock.
Step 15: Make a Cover for the Lock
Cut 1/4 inch thick end pieces (1/4x1 1/4x3 1/2) and glue them to the front panel so that the top and bottom of the lock is protected. If you like the clear cover better to show the workings of the lock, find a piece of plastic or glass. The cover panel can be glued or screwed to the lock.