This is “Der Mumienkönig” - “The Mummy King”. It is an ancient artifact of unbelievable worth.
Well, actually it's just a somewhat funny looking flint stone I found on our trip to Rügen earlier this year. But I like it and wanted to put it on display.
Of course a king needs to stand upright, so some kind of stand was needed and this is how my evening turned into a new 3D printing adventure…
The stone at the bottom is irregularly shaped. Ideally, the stone should fit perfectly into the holder, so a near perfect measurement of the shape would be needed. My idea was to take an imprint and then transfer it to a 2D sahpe somehow. Kaddi had the brilliant idea to use wax for that.
So I heated up a tealight and took an impression:
To transfer the shape of the imprint to the computer, I traced the border with a sharpie and put the thing to my scanner.
I then imported the scan into Inkscape and traced manually traced the outline, making sure to use only straight lines - no Beziers here.
Now I had the right shape, but the dimensions were still wrong. I measuerd the width of the imprint with my calipers and adjusted the shape's size in Inkscape accordingly. I also moved it to position
To get a usable DXF from my shape, I basically followed the tutorial at RepRap Prescription. It basically boils down to having a path with straight lines only.
However when saving your file as DXF, make sure to uncheck all the option in the save dialog and set the units to
Time to make use of the shape in OpenScad. It's a simple matter of importing it and linearly extrude it along the z-axis:
This gives you a 3D shap you can use to cut out a hole from any other OpenScad primitive.
Export your work to STL and you're ready to slice it in your favorite slicer.
Using the excellent OctoPrint of course.