I have long loved Topography and maps and love the visual you get by seeing the terrain topography. I also love how amazing Google Earth is dealing with the terrain. It seems magical to me. I wanted to see what we could do with the Google Earth. We have found .STL files of existing terrain, but I wanted to customize it to a specific location. The San Juan Islands. I tried this a few years ago, but the process was very involved and I gave up on some other pursuit. I looked at retrying hoping that someone had gone to the work of simplifying the process. I was in luck! I found terrain2stl. .Stl files are simply a triangulated surface of a 3D shape that is usable by almost any 3D software. I think of it as the .PDF file of the 3D world. It is complicated to manipulate once made, but easily transferable to post process for manufacturing.
With Terrain2stl.com you simply choose your map area, select and alter your parameters and you are given an .stl file for your machine. I did find that an area too big or too small yields odd results, but a grouping of islands worked perfect.
For this carving, I tried most of the settings and found one that looked great in wood at the desired carve size. I did a vertical scale of 4 and a water height of 1mm. That made sure each island had some definition, gave the really flat islands some definition and didn’t get too crazy tall on the mountains. That said, 4 on the vertical scale was maxed out, so I can’t say that I wouldn’t have tried higher.
Once imported into Vectric Aspire, the toolpaths are similar as other roughing and finish passes we have done. We did a .5 ball end on a roughing pass using 3D vector button. We did a final pass with a .25ball end at 30% stepover. That cleaned it up enough that I wasn’t worried about breaking off the 3 inch long .125 ball end that we use so frequently.
We also modeled the boundary line between Canada and America. Then, we also Modeled the San Juan Island words. That was all that was planned and we were ready to carve.
We prepped up a 20 inch by 15 inch piece of Spanish Cedar that was really clear so as to not distract from the carving.
While it was carving 2 things happened. 1: the Z axis started drooping on us. It ended with lines in it that I can live with, but I will have to keep an eye on the machine for Z axis issues. 2: we decided to add the names of the islands. We made a V-Carve of about 15 named islands and prepped that to be done after the finish pass.
Here is a picture of the work to put the words on.
And some final pictures!