OpenSCAD Build Plate Layout Grid

thingiverse

An array of small cubes across OpenSCAD's Z=0 plane provides a visual reference to simplify arranging objects on the build plate. Instructions OpenSCAD displays the coordinate axes (tap Ctrl-2), but provides no indication of the model's actual size. When I arrange parts on the platform, this grid helps me position them correctly and provides a quick size check. The chunky set of parts show an actual build plate. They assemble into a rugged bicycle taillight mount (described at http://softsolder.com/2012/01/03/planet-bike-superflash-tour-easy-mount/) and required a bit of to-ing and fro-ing to position correctly. The cube() statement inside the nested for loops has the % prefix character (described on https://secure.wikimedia.org/wikibooks/en/wiki/OpenSCAD_User_Manual/Modifier_Characters) that colors the cubes transparent gray and prevents them from rendering into the final model that becomes the STL file. As a result, the layout grid vanishes when OpenSCAD compiles and renders the object using CGAL (tap F6): the final STL contains only your model's parts. The image of the compiled sample shows just one lonely 2 mm cube at the origin: it's supposed to look that way! You should see an array of squares on the bottom surface of your build plate, because the bottom surface of the cube array lies exactly at Z=0. If you don't see the squares, then your objects extend below Z=0 and the extruder nozzle will gouge the platform. The default parameters produce a 100 x 100 mm array of 1 mm cubes, which is good enough for my purposes. If you're pushing the limits of your printer's build platform, modify the code to cover the full platform... and verify that your homing routine puts the (0,0,0) origin exactly in the middle of the plate. A few more details are at http://softsolder.com/2011/08/22/revised-openscad-layout-grid/.