add dimensionHelper

README.md

@@ -92,3 +92,7 @@ For generating a specific part:
 
 `rbuild.py` also support an optional `--nightly` flag, which will run a nightly build of OpenSCAD. Please make sure the
 path to the nightly build is also configured in [rbuild.py](./rbuild.py).
+
+## Designing rack-mount items
+
+Some useful variables for designing your own rack-mount items can be found in [rack-mount/dimensionHelper.scad](./rack-mount/dimensionHelper.scad).

rack-mount/dimensionHelper.scad

@@ -0,0 +1,10 @@
+include <./common.scad>
+
+// OpenSCAD script to output some helpful dimensions for creating new rack-mount items:
+
+echo("Vertical distance between 2 main rail holes: ", screwDiff);
+echo("Horizontal distance between 2 opposing main rail holes: ", rackMountScrewWidth);
+
+echo("Max supported rack-mount width: ", maxUnitWidth);
+echo("Max recommended rack-mount depth: ", maxUnitDepth);
+