Combination Lock Assembly Instructions

Please read the General Instructions for Acrylic Models first, then watch the video below.

Be sure to watch this video before you try to put the model together. Make it full-screen using the icon in the bottom right of the video player. And please pay attention to these following updates to the assembly instructions.

Note on disk friction

During the assembly process you will encounter three bent washers made of thin polycarbonate. They have intentionally been creased to make them wavy. This creates a controlled, stable amount of friction that makes sure the code disks stay where you dial them in to. However, if the creases are too strong, you can end up with too much friction, making the dial hard to turn, especially when it’s turning all three disks at once. The disks only need to be a little bit wavy: just a touch of friction is enough. So I recommend you press them flat or even un-bend them a little before assembly. If you end up with too much or too little fraction after putting together the code wheel pack, you can easily take them back out and fold them more or less. Because polycarbonate is a very tough material, once assembled they will provide a stable amount of fraction indefinitely.

The Hair Tie Solution

We have discovered that the rubber bands we were supplying with this kit tend to deteriorate and break far too soon. As a solution, we have switched to black hair ties for the tension that pulls the fence down against the gates in the lock mechanism. Hair ties last much longer. Where the instructions show the rubber band being looped over twice, just apply the hair tie instead, not doubled-over.

No Longer Including Paper Blind

The instructions mention a black paper blind that lets you block the view of the code wheels while turning the dial. We no longer include this in the kit because it turned out to be an undue amount of trouble, and of very little value.