Intro: Wooden Bar Combination Lock
This is a fast, relatively simple project that can be completed inside of 3 hours if you move quickly and don't make any major mistakes. Further you can plan around irregularities in your workpieces allowing for greater ability to use scraps.
3/4 inch pine
Step 1: Cut Peices
Take your 3/4" pine, and plane it relatively even.
2 9x12" boards
2 3x12" boards
1 tapered 2,1/2x32" board, tapering out to 3,1/2"
5 3x24" boards
16 3,1/8x3 boards
10 3x1" boards
Arrange your materials neatly, affix the 3x12" boards to the sides of one of the 9x12" boards creating a notch in the middle
Step 2: Check Your Taper
If you have set the taper correctly on the 32" long board, it should slide into the notch, but not slide THROUGH the notch, it should snugly stop advancing if you attempt to slide it along. This is important if you want the lock to only release in one direction.
Step 3: Dry Fit, and Then Glue, Bars and Risers
Arrange the bars and risers (3x24" pieces and 3,1/8x3" pieces)- The 3,1/8 pieces are ever so slightly higher then the 3" pieces allowing for them to slide with ease. Then carefully fasten them in place, I used wood glue, be sure not to let them slide about, or let the glue drip. Wait until dry.
Step 4: Mark Gaps With Grease Pencil
Mark the gaps with the grease pencil, the individual 'tumbler' stops will be placed here to prevent the rod from sliding out.
Step 5: Add Stoppers
In this case I just loose fit some 1,1/2" screws, drivigin them in just enough so that they did not protrude out the other side of the wood. Always pilot your screw holes!
Step 6: Cut Notches in 24" Boards
Not pictured; but each 24" board needs a notch cut into it large enough to admit the screw- preferable with some play, but if you want to make the lock far more infuriating, or simply provide more, more accurate, numbers you can make it so small so that the screw barely has any side to side clearance. Assure you have adequate top to bottom clearance.
Step 7: Add Guides, Lines, and Numbers
Screw on the other 9"x12" board on top of the previous one, sealing the boards inside
Use the 10 1" pieces of wood to cap each bar, so that they cannot slide out.
Use the remaining pieces of wood to construct a guide for the tapered piece of wood to prevent it from skittering about, note that one board will have to be cut as shown so admit the screws.
CAREUFLLY look inside the mechanism so that you can see right through it (IE- all notches are lined up), and draw a line on the side you are keeping your marks on with your red grease pencil. Then slide all off the bars out and put your numbers on. You can see that the combination for this lock is 3,8,3,8,3 (Hopefully none of the food thieves I am trying to keep out of the fridge read instructables!)
Slide the lock bar into place multiple times (screws facing down) in order to make sure that you have not shifted anything while applying your numbers and lines- if you find that one has shifted and is marked incorrectly sand and then reapply.
Step 8: Zero, Test, and Then Mount
Zero the bars by pushing them all to one side.
Then put the code in and try sliding it out again, do this 2 or three times, just to make sure that there is not a burr in there or something similar that will prevent use.
Then mount it wherever you need your stylish, functional, wooden lock.
Thanks for reading this instructable, hope that this gets the creative juices flowing.