I have been running a series of six half marathons, in different European cities (Lisbon, Berlin, Cardiff, Prague, Valencia and Copenhagen) with some friends. I thought I’d try to create personalised slate coasters with the course maps laser-engraved on them, for Christmas presents, to celebrate the achievement.
Simple, you’d think, but it turned out to be a bit more complex than I thought. First, get the maps. This involved reading a few forums on the best way to get vector maps. The consensus was to use a piece of software called QGIS. Lots of tutorials later, and I was still in the foothills of the learning curve. Eventually, I managed to work out how to build queries to import roads, coastlines and waterways to get the right level of detail for the engraving.
Next, overlay the different half-marathon courses for each city. This was relatively simple: find .gpx files for each course, download, and import into QGIS.
Next, export the maps and running route as an .svg file, another slog up the learning curve, and finally I had a map! But nowhere near finished…
Next came cropping the map to the coaster shape, overlaying the title, name, year, etc. Using Inkscape for vector artwork worked well but the maps were a messy .svg and caused problems with boolean crop, lots of flattening and simplifying and trial and error later, and we finally had a decent looking .svg ready to send to my Snapmaker2 A350 laser engraving machine.
Next, importing into Luban, building two different tool paths, one for the fine detailed map, and another for the filled text and route.
Several test engravings on paper, then slate, to get the work’s origin, focus and depth of engraving just right.
I watched a couple of YouTube tutorials on the best finish for the slate. Painting on a mixture of 50% danish oil and 50% white spirit before engraving worked for me. This turned out to really help the contrast, making the black slate much darker so that the map stood out better.
Setting up some positioning guides on the laser bed helped with repeatability. Each one took about 30mins with my puny 1.6w laser. Engraving 9 coasters in total, for the 3 races we had already run. Only 3 more races to run🤪and 3 more city maps and 9 more coasters to engrave!
I loved how these turned out, the super sharp lines the laser makes look great. I gave the first 3 each out as Christmas presents with a hint of 3 more to come once we’ve completed the rest of the races.
