Improve rack-mount. Individual rack-mount systems are now organized in their own directories, with a standard entry.scad file.

rack-mount/enclosed-box/helper.scad

@@ -0,0 +1,21 @@
+include <../common.scad>
+
+// Some utility functions, as well as global functions to make code cleaner
+
+sideRailLowerMountPointToBottom = uDiff/2;
+sideRailBaseWidth = 15;
+// distance between front and back main rail screw mounts
+sideRailScrewMountDist = yBarDepth - 2*(frontScrewSpacing + railFrontThickness + railSlotToXZ);
+
+boxPlateScrewToXEdge = 4.5; // wow these are named poorly
+boxPlateScrewToYEdge = 5;
+
+
+function findU(boxHeight, minRailThickness) = max(1, ceil((boxHeight + 2*minRailThickness)/uDiff) - 1);
+
+function railBottomThickness(u, boxHeight, minRailThickness, zOrientation) =
+  (zOrientation == "middle")
+  ? (((u+1) * uDiff) - boxHeight)/2
+  : (zOrientation == "bottom")
+  ? minRailThickness
+  : minRailThickness;