Mount Ruapehu - Desk Model

Overview

• This is a simple desk model of Mount Ruapehu (a volcano in New Zealand).

• More information can be seen here: https://en.wikipedia.org/wiki/Mount_Ruapehu

• The mountain has a crater lake, and the lake seen in the northern end if part of a n area between Mount Ruapehu and Mount Ngauruhoe.

• Two versions are provided, a blended colour multi-material , and a dual colour multi-material.

• The blended colour multi-material gcode was generated using PrusaSlicer 2.9.6 using four filaments (white, blue, brown and black).

• The dual colour multi-material gcode was generated using PrusaSlicer 2.9.5 using simple black and white filaments.

• I've included the raw topographic files (images and metadata log file) and img-to-stl (repaired) mesh object for interest.

Post Print assessment

• The blending is remarkable and the approach very novel.  Clever of Prusa to look ahead and ensure the MMU3 supported 5 filaments (CYMK+W) on introduction.

• In this use case the method is not ideal as the the tops of individual layers become visible as elevation increases gradually, if viewed from the side however you can clearly see the colours blending as predicted.

• I used a distinct blue for the lakes, but as can be seen in the photos, the contrast between white and blue is large, and I did not adjust purging volumes to ensure the white wasn't blended with some unpurged blue in the extruder. Indx extruders should solve this with no waste.

• I've also  provided a two colour version, as the lakes can always be painted or coloured in with a blue sharpie post print.

• The method discussed below of managing complex meshes outside of a parametric design tool like Fusion360, and combining objects in PrusaSlicer worked very well and save a lot of time and frustration.

Printing

• You will need to use an MMU3 (or compatible system) as the colour should blend to white (snow) as the altitude increases.

• If you don't want to use the colour blending version. Use the dual colour multi-material version

Assembly

• No assembly needed. Prints as one piece with no supports.

Method

• As anyone who has ever tried to edit a mesh of a topographic feature in Fusion360 will know. Its a nightmare. (So, from previous experience,  I didn't).

• I generated a jpeg  image showing colour relief of the area using open topography and then fed that into image to stl to generate a suitable mesh with exaggerated height.

• I then used Fusion360 to create a "cookie cutter" object (basically two a nested cylinders that resembled a donut)  and imported both mesh objects into Microsoft 3D Builder.

• I subtracted the cookie cutter object from the open topography mesh, which left me with a clean mountain object within a bound cylindrical object (the donut hole) of precise diameter. The body of the 'donut', removed all other parts of the mesh object cleanly.

• I then used Fusion360 to create a baseplate with parametric features needed by the model, and exported it as a mesh. The baseplate accounted for the donut hole that would be added later in PrusaSlicer precisely.

• For the blended multi-material version

  • I imported both the baseplate and the clean mountain meshes into PrusaSlicer 2.9.6 as parts of the same object. Then aligned them so they appeared as a single object where the cylinder mesh sat precisely in the baseplate where it had been allowed for.

  • I then applied multi-material colouring  via virtual extruders to define areas of the model for printing, and generated the gcode you see here.

• For the dual colour multi-material version

  • I imported both the baseplate and the clean mountain meshes into PrusaSlicer 2.9.5 as parts of the same object. Then aligned them so they appeared as a single object where the cylinder mesh sat precisely in the baseplate where it had been allowed for.

  • I then applied multi-material painting to define areas of the model for printing, and generated the gcode you see here.

Key Takeaways for dealing with complex meshes (i.e. Topographical relief)

• Microsoft 3D builder is the best tool I have found to edit complex meshes in this manner.  PrusaSlicer is good for simple cuts, but I could not use another mesh as a cutting tool like I did in 3D Builder to allow me to then export the trimmed mesh object.

• The tool is no longer updated or available. But someone has saved it  to github https://github.com/ccatlett1984/3dbuilder. As with any internet download, you use this at your own risk.