This puzzle box has a slider puzzle in its lid. You have to scramble the picture to move the two corner tiles up and unlock the box. When you solve the puzzle, the lid pops open and the box plays a birthday song.
This is no ordinary slider puzzle. At first glance the is no room for the tiles to move! Also, not all tiles are square, and one of them is permanently glued in place.
You have to figure out that two of the tiles can be pushed inside. They are attached to latches made for cabinet doors
When both of the tiles are pushed, they open up some space for the other tiles to slide.
The box has 3 main components. The body, the music player, and the puzzle lid.
The music device is scavenged from a Hallmark birthday card. Its power switch is replaced with a series of 2 momentary switches and one master toggle (to turn off the music if it gets annoying).
Random Rant: Why is it sooo hard to find a card that sings a classic Happy Birthday 🙂
The lid has a frame that is machined from solid wood, a grid plane, and the bottom cover.
The grid plane is made from plywood for improved durability. An earlier prototype had it as part of frame, but it broke during testing.
The puzzle picture starts as one solid piece. It is then cut into tiles
One of the tiles is glued into place, and two are attached to the locks and can only slide up and down. The sliders have tiny magnets to keep them in locked position.
It is important that the tiles move easily around. The bottom is treated with shellac and sanded. This makes them very slippery. In addition, the top is sprayed with anti-slip spray to make them gripper when you push them with your fingers. The MDF surface is made ever more slick by rubbing it with furniture grease.
Make it
Download the plans from here: slider_box.zip
The main materials are 3mm plywood, 5 mm plywood, and 3mm MDF.
The lid frame is made of solid oak. Find the Fusion 360 plans here: https://myhub.autodesk360.com/ue2b630b8/shares/public/SH919a0QTf3c32634dcf548ba807ecd01d18
Other materials:
- 4 x 20mm barrel hinges https://www.amazon.com/gp/product/B07GCL755D
- A latch mechanism like this https://ahturf.com/store/index.php?route=product/product&product_id=49547. Possibly a clicker from a ballpoint pen can also be used
- Music player from a greeting card
- Furniture grease: https://www.amazon.com/Mohawk-Finishing-Products-M750-1203-Lubricant/dp/B07Y2FYZ13
- Anti-slip spray: https://www.thepaintstore.com/Krylon-Non-Skid-Coating-p/k03400000.htm
- Tiny magnets, some switches, a tiny spring