Customizable Sphere Lithophane

-- Summary --

This is a customizable spherical litophane. To make your litophane you just have to replace one ".png" image file, load the 3D model in Blender, and export as STL.

It was inspired by RCLifeOn's World Map Spherical Litophane although I use Blender instead of 3D Max.

The lithophane360.blend.zip is a 360º version. You will need an image with two times more pixels horizontally to cover the sphere without the image being distorted. Also keep in mind this is a way heavier blend file and will take longer to process by Blender.

-- Instructions --

   Download all the files. The image to be replaced is "final.png". This file needs to be in the same directory as the blender file.

Preparing the image

   You will need to convert your image to black and white, AND invert the colors in an image editing program. So, in the final image, darker pixel means thinner walls, and lighter pixel means thicker walls.

   The template image is 2559x1498 pixels wide. You will have to convert your image to have the same aspect ratio, by adding black colour rectangles to top and bottom (if it is wider than the template image), or to left and right (if it is narrower). If you don't do this, the image will be distorted (streched).

   The color of the image borders will extend to the rest of the sphere, so they should be black to have the sphere as thin as possible.
   Export your image to PNG format and place it next to the blender files, and rename it to "final.png"

Generating the STL

   Download and install Blender: https://www.blender.org/download/

   Open one of the three ."blend" files in Blender. The one with hole has a small hole in the back to pass a cable for a LED light that will illuminate the lithophane. The one with 360 (zipped) is the 360º version, which needs the image with double width in pixels.

   Once opened (it will take a while), make sure that the object "Sphere" is selected in the objects tree in the upper right corner in the Blender window. This object is the one to be exported. If it is not highlighted, just left-click on its name.

   Select Menu File -> Export -> "As STL file...".

   In the export options, it is VERY IMPORTANT that you select the option "Only selection".

   Select the desired export scale option. The exported sphere has 2 mm size. So for example setting the exporting scale to 50 will give a 100 mm sphere (alternatively you can leave the scale to 1 and scale the sphere afterwards in your slicer program)
   Finally, click the Export button in the upper right corner. After a while you will have a stl file in the same directory. You can now close Blender. Enjoy! :-)

-- Print settings --

Mandatory print settings

   100% infill.

   Lower the filament flow ( 90% to 95%, I used 93%)

   No supports.

   Slow speed, max 45 mm/s.

   9 mm brim for bed adhesion

Advisable print settings

   0.2 mm layer height.

   Adequate retraction settings.
   White or light color filament.