This is a concept combination lock in the form of a model grand piano. The combination is fully customizable using any combination of the given keys. Note that the order does not effect the combination.This is not designed for extreme security uses and is more of a concept piece.
This Thing includes all relevant files for printing in .STL form, as well as 3 assemblies in .STL format; a full assembly showing the exterior of the model, a semi-complete assembly showing the interior of the model, and an expanded assembly illustrating all pieces contained in the model.
This Thing also includes all relevant files in .SLDPRT form for easy modification for your specific materials and requirements. Specific sizing for springs, dowels and magnets will not be provided, as I found that it was very difficult to find exact sizing that worked consistently.
The method for unlocking the piano is as follows:
- Press the correct keys
- Pull on the slider dowel
- Open the piano lid, revealing the container space within
The method for locking the piano is as follows:
- Close the piano lid
- Push on the slider dowel
- Insert the locking dowel into the side holes and press up
- The piano should now be locked, and the lid should be held closed
You will need the following additional pieces along with the files provided:
Super Glue, 4 dowels (preferably metal) of length no shorter than 18cm, a series of small springs, and a collection of small circular magnets.
Begin with the Piano-Outline piece. This is the main body of the piano.
Using the super glue, take the circular magnets and secure them in their designated spots on both the main piano body and the individual levers. Ensure that coincident magnets are oriented correctly as to induce attraction.
Take your preferred sliding lock piece and the corresponding nub. Using the super glue, attach the nub to the sliding piece using the models provided as a reference. The the top of the nub should be coplanar with the top of the sliding piece, and it should be centered horizontally.
The orientation of the levers is also important. In relation to the axis hole in the center of the levers, one side is longer than the other. The longer side will be oriented towards the piano keys, while the shorter side will be oriented towards the back of the piano.
Using your springs, take each key and position it in its correct position on the piano (You can look up a normal piano as a reference) and place it in its space. The springs should fit snugly around the nubs on the piano key pieces and the piano outline.
Place the small construction piece over top the keys. It should slide in snugly with the main piano body.
Place the levers one by one their desired locations. As you place them in, slide the rotation dowel through the hole on the side of the body, securing them on the axis. The rotation axis should remain mostly still as the levers rotate along the dowel's body. This creates the foundation of the mono-stable lever system. Give each lever a few rotations to ensure correct orientation and agility.
Take your preferred sliding lock piece and insert it vertically into the lever area so that it slides around the levers. Take your second dowel and push it through the side slot of the outline piece as well as the side of the sliding piece, giving an exterior handle for sliding the lock mechanism.
If all levers are pushed down, the lock piece should be blocked from moving, and conversely if all lock pieces are up, the lock piece should be moveable.
Take the piano-cap piece and place the third dowel in it's position. It should fit in securely and not rotate.
Move the sliding lock to the unlocked position and place the cap on top of the piano body, securing it in place.
Attach the piano lid to the dowel, it should rotate freely. Close the lid and move the sliding lock to its locked position.
Take the final dowel and insert it through the bottom of the vertical slot on the side of the piano body. Press up until the levers click. The sliding piece should now be immovable, and the lid should be secured. You can now unlock and lock the Piano.