A Backlit 3D-Printed World Map: Design Notes

The Idea

A 2×3 ft wall piece made of 12 hexagonal tiles. Each tile is a white PLA cap that glows when lit from behind, with black terrain relief printed on top. The tiles sit on printed LED light boxes. I started from a 12-hexagon world-map model and scaled it 1.22× to fit the frame. The target printer was a Bambu P2S with 0.2, 0.4, and 0.6 mm nozzles.

1. Fixing the Geography

The source model had the Persian Gulf filled in and no Caspian Sea. I used an elevation and water-mask map (the three-globe earth-topology data) to carve out the Caspian, the Persian Gulf, and other inland seas, then applied the same pipeline to every tile.

2. Islands Without Supports

Carving left some islands disconnected from the mainland, and bridging them with small supports would have looked wrong. The fix was to print the terrain relief directly on top of a thin 0.8 mm white cap.

The cap holds every island in place, and light shines through it. Each tile is one two-colour object: black relief on top of a white cap. A thin white cap is thin enough that you can almost read a laptop screen through it.

3. Honest Terrain

My first relief version capped the maximum height, which flattened mountain ranges into artificial plateaus. I removed the cap so the remaining flat areas are real plateaus in the data. This added only about 0.1 g per tile, so it was effectively free.

4. City Flags

• Tiny Ø1.8 mm blind holes mark 94 cities in the relief.
• The flags print flat, because standing flags would need a lot of support.
• Each flag is a 10×6.5×0.8 mm swallowtail pennant with a small peg.
• They print in red and gold, 20 per plate, and press-fit into the holes.

5. Holding It Together: The Part That Took Iteration

• Round 1: The first magnets were too weak and barely held the tiles flat.
• Round 2: Switched to 10×5×2 mm N52 block magnets, with 6 per tile at the hex edge midpoints (144 in total). I also added more clearance, because printed pockets are never exactly the size you design.
• Round 3: Plastic pins would have been fragile, so I used M3 heat-set threaded inserts as shear pins. There are three per tile, with matching holes on the light-box side so no support is needed.
• Round 4: N52 magnets are strong enough to leap out of the pocket and onto the nozzle during a print pause. The final design slides each magnet in from the side through a tunnel after printing, then seals it with a small press-fit plug. This needs no pauses and no glue.
• Note: N52 starts losing strength above about 80 °C, so heat-setting the magnets themselves is out.

6. Print-Time Optimisation

Printing the tiles with a 0.2 mm nozzle at fine layers looked very smooth but took forever. The light box is identical across all 12 pieces, so it’s now a separate file, printed once with a 0.6 mm nozzle and thicker layers. Layer height and line width are separate settings, and Bambu Studio’s variable layer height can print the visible top surfaces finely and everything else coarsely.

7. Assembly Process

1. Heat-set the inserts into the tile corners first.
2. Slide the polarity-matched magnet pairs into the tile and box through the side tunnels, cold, with plastic tweezers.
3. Press in the plugs.
4. Lower each tile straight down onto its box.
5. Press the flags into the city holes.

Lessons Learned

• Designing around a cap and relief solves the floating-island problem.
• Make pockets looser than the CAD says.
• Don’t insert strong magnets mid-print, because they will jump out of the pocket.
• Heat-set inserts make much better pins than printed plastic.
• Splitting one print into separate files can cut hours off the total time.