What this means is that, rather than use perpendicular X, Y and Z axes to move the printer around, it uses three parallel axes and a series of parallelogram-based arms to move around the print head (the "hot end"). If it sounds confusing, that's because it is - it's easiest to understand if you watch this small segment of my video about it.
Because of the movement mechanism, working out how to move the motors so that the print head ends up in the right place not only involves some complex trigonometry for the printer's CPU to do, it means there are fifteen or so different parameters to adjust during calibration. I had managed to get the printer calibrated so it was flat and level, but try as I might, I could not remove the very slightly rhomboid shape it was giving to all of my prints.
I solved this by, of course, buying a new 3D printer - a cartesian one. The Cetus 3D which I purchased is relatively inexpensive at US$300, but does really good quality prints for the money, and more importantly, they are nearly perfectly square. The Cetus also helpfully has much better control over "stringing" than the Rostock, which I suspect is due to the direct drive extruder.
Fabrication Methods
As I was making this second map, part of me was trying to consider alternative methods of fabrication to overcome some of the inbuilt limitations of 3D printing. The two I looked at in particular were CNC milling and casting.
CNC milling is sort of the reverse of 3D printing - it is about removing material from a starting block rather than adding it to a base. It's incredibly precise, and allows you to machine things out of harder plastics or metals, but it has a serious drawback, which is its speed.
The 15cm tiles might take 10 hours to 3D print, but to mill them out of even soft plastic would - with the machine I have access to at a local makerspace - take around 20 hours, with several tool changes.
That machine doesn't have an automatic tool changer, and I can only use it in four-hour blocks, and so as much as I would love to mill the tiles out of aluminium or frosted acrylic, I would need dedicated access to a milling machine. I have, however, pursued other terrain projects on the milling machine, which you can see a sneak preview of at the end.