Okay, so Valentine’s Day is coming up this week, and while mb isn’t into the whole valentiney thing, I’ve always been a bit of a hopeless romantic. She rather liked the demo piece I made of the area she and her sisters backpacked last fall, so I figured I’d do it up all proper and giftlike.
That’s the standard to-scale process, with 36mm baltic birch plywood as the stock (by gluing two 18mm pieces together). This is actually the second copy, as the first had a void that resulted in a bit of unscheduled geologic alteration. It’s not bad, but I figured I’d give it another round, seeing as there’s nothing like a present that presents the present state of the terrain. The layer variation in the second also looked cooler.
So, standard procedure. USGS DEM data into QGIS. Use the plugin to create a heightmap. Run the CAM via PixelCNC. Extract the trails from NPS vector data, using Inkscape to turn the DXF into a properly scaled SVG. Process the paths and heightmap with my special python code. Then run the roughing pass (1/4" ball), finishing pass (0.5mm radius taper), and engraving pass (0.25mm radius taper, Z-0.2mm). I decided to add the V-carved text, which I drew in Inkscape, processed in Carbide Create, and cut with a 90° V-bit.
I did a quick video (with poor focus and loud router noise) of the engraving pass, just to give an idea what it’s like. I optimized the SVG to join all the segments to make it just a single path. (In Inkscape, choose the node edit tool, click a path, then shift-click the path to join. Drag a select box around the end node of the first and the overlapping start node of the next, then click the “join selected nodes” button. The two paths are now one continuous path in the SVG.) Anyway, the loud, poorly-focused video clip:
After it was cut on the Shapeoko and the corners rounded on a belt sander, I took a 5/0 spotting brush and some medium viscosity acrylic artist-type paint and meticulously hand painted over the engraved trails. In hindsight, if I thought about painting them, I would’ve engraved them as lightly as possible while still being able to see them as guides when painting them on. The wood fibers tend to grab at the tiny little brush. I added little dots to mark where mb camped each night, and then I painted the V-carved letters. After the paint set, I lightly sanded over the letters, and the edges cleaned right up. (The gel-like paint didn’t seep into the wood fibers like other more fluid paints I’ve used.)
I’ve put a few coats of lacquer over it so far, and I may do a bit more finishing, but I figured it was good enough to show off here. Just don’t tell mb. It’s a surprise. 
