We all have a place that we love, so, why not turn it into an ornament for our home?
We now have the technology to precisely replicate every landscape that we want, and some are not even of the earth!
This time I made a gift for a friend of mine that graduated from the aerospace engineering university, so the subject is the Gusev crater, the landing site for the Spirit rover on Mars, but I will tell you also how to machine your favorite valley.
The most difficult part of this project is selecting the area that we want to carve out from our material (we have a world of options), so we can start from where we live or the place that conquered our hearts on vacation.
Fortunately, we have more than one option that converts the satellite topography data into an .STL file that we can later directly use to generate the machine code for the mill or a 3D printer.
To obtain your 3D file I suggest you use one of those two options which are:
-Terrain2STL – https://jthatch.com/Terrain2STL/
-map2STL – https://map2stl.com/
They work in a very similar way, you will have to select the center position of the rectangle that you want to convert, select its dimension and (particularly for flatter areas) you have the possibility to exaggerate (or decrease) the vertical scaling of your model to make it appear more realistic.
Other options are the water drop that makes the water base lever lower than the coastline (it works only for the sea surface) and the base height that adds some material under your model to make it stronger.
In my opinion, I do not see major differences in the quality of the model generated but a plus feature that map2STL has over Terrain2STL is that you can view a little preview model before downloading it so you can tweak your settings without the need to download the file, open it and then going back changing them.
Other minor differences between the two are:
-map2STL lets you know the actual dimension in km of your box and the final dimension of your generated model (that is also tweakable)
-Terrain2STL lets you rotate the selection box, the measures are in degrees and not in km.
Now that we have our model generated we can open it with the CAD-CAM software of our choice and set all the machining parameters in order to generate the code that will make our mill (or 3D printer) run.
Since the mill that we are going to use for the detailing (finishing) will be fairly small and possibly fragile is better to perform a roughing pass first.
The type of mill that we are going to use for the roughing is up to us and it depends on the scale of the piece and the material, bigger and flatter the piece bigger the mill diameter can be
If you are going to use wood I suggest using medium to hardwoods since they tend to leave a better finish when milled.
I started by using cherry wood which is fairly easily machined and is not so expensive. Its always better to perform some testing before buying a big slab of material.
We can now proceed to the milling phase so we just have to secure our piece to the CNC and run the program!
For this job, I used a 6mm flat bottom end mill for the roughing passes and a conical 3.8° mill with a 1mm radius end, this one has done a very nice job and permitted me to get a very nice level of detail without taking too much time. If you want to have extreme detail you can choose a smaller radius of the mill and/or perform closer passes to get better resolution. Please note that this requires an awful lot of machining time and smaller bits are more fragile so you need to be extremely careful to set the milling parameters to not break it.
Once the mill has finished the job the only thing left to do now is take out the piece from the mill, finish up the edges (if we did not before ), and admire the beautiful piece of art we have just made.
For extra-terrestrial landscapes and much more, you can visit the NASA site right here: https://nasa3d.arc.nasa.gov/models
