Coastline and Topographic Lithophane Earth Globes
Model files
sphere_stand.3mf
A20200504_ultrahires_topo_n_hemisphere.3mf
A20200504_ultrahires_topo_s_hemisphere.3mf
northbuild-newshell.3mf
southbuild-newshell.3mf
LedLight-simple.3mf
lazySusanBottom.3mf
lazySusanTop.3mf
lazySusan.scad
Model origin
The author remixed this model.
Differences of the remix compared to the original
I resized the globes to 100mm in diameter, and in PrusaSlicer I subtracted a sphere 96mm in diameter so that, when lit from within, the oceans would be brighter than the land.
In PrusaSlicer I resized the Stand for a spherical object for my 100mm diameter
In PrusaSlicer I subtracted a 6mm cylinder from the center of the South Pole so I could put an LED in the center.
Each globe rests on a lazy suzan I wrote in OpenSCAD, powered by a single 605 skateboard bearing. I used circular infill for the top and bottom layers to get the nice surface.
Edit: rather than concentric, if you use Archimedean chords for the top and bottom infill patterns you'll get rid of an annoying seam line.
For the LED illuminators, I used the Compact LED Light for CR2032 documented here. I wired up the battery holders using stiff wire, then used an alligator clip as a clamp to solder the white LEDs at the right height so that the LED would be at the center when everything was assembled. I used a drop of hot glue on the top of the holder to make sure the LED stood upright. The LED is wired with the long, +, leg to the outside, and the battery goes in negative side up. The battery doubles as the on-off switch: push it all the way in to turn on, push it out a bit to turn off. No resistor needed.