parametrize screw/hex nut types

.idea/codeStyles/codeStyleConfig.xml

@@ -0,0 +1,5 @@
+<component name="ProjectCodeStyleConfiguration">
+  <state>
+    <option name="PREFERRED_PROJECT_CODE_STYLE" value="Default" />
+  </state>
+</component>

cases/rack2/config.scad

@@ -23,10 +23,12 @@ screwDiff = 10;
 numRailScrews = 20;
 
 // Screw type used for rackmount units. See screws.scad.
-railMainScrewType = "m4";
+mainRailScrewType = "m4";
 
 // Screw type used to affix side rails.
-railSideMountScrewType = "m4";
+mainRailSideMountScrewType = "m4";
 
 // Screw type used for constructing the actual rack frame.
-rackScrewType = "m3";
+rackFrameScrewType = "m3";
+// Currently, only m3 screws are supported here (tolerance issues)
+assert(rackFrameScrewType == "m3");

cases/rack2/mainRail.scad

@@ -1,108 +1,48 @@
 include <./config.scad>
 include <./screws.scad>
 
-// Distance between the middle of a screw mount and the rail's vertical edges
-railScrewHoleToInnerEdge = 5;
-railScrewHoleToOuterEdge = 5;
-
-// Distance between the midpoint of the rail screw holes.
-rackMountScrewWidth = maxUnitWidth + 2*railScrewHoleToInnerEdge;
-
-railFrontThickness = 6; // Make sure that the nuts for the chosen screw type can slot within the front face
-railSideMountThickness = 2.5;
-railOtherThickness = 2.5;
-
-
-// Extra spacing for the rack unit screws.
-frontScrewSpacing = 8;
-
 /* Small horizontal planes at the top and bottom of the main rails. Used so we can fasten the rail to the frame
    Note that this value is also used for a depression at the bottom/top of the frame for aligning the rail */
 railFootThickness = 3;
 
-railTotalHeight = screwDiff * (numRailScrews+1) + 2*railFootThickness;
+railTotalHeight = screwDiff * (numRailScrews + 1) + 2 * railFootThickness;
 
-
+mainRail();
-sideSupportExtraSpace = 2;
+echo("Total Rail Height = ", railTotalHeight);
-sideSupportScrewHoleToFrontEdge = 5;
-sideSupportScrewHoleToBackEdge = 4.5;
-sideSupportDepth = sideSupportScrewHoleToBackEdge + sideSupportScrewHoleToFrontEdge;
-
-frontFaceWidth = railScrewHoleToInnerEdge + railScrewHoleToOuterEdge;
-
-
-module _frontRailSegment() {
-    difference() {
-        cube(size=[frontFaceWidth, railFrontThickness, railTotalHeight]);
-
-        for (i=[1:numRailScrews]) {
-            translate(v=[railScrewHoleToOuterEdge, railFrontThickness/2, i*screwDiff + railFootThickness])
-                rotate(a=[90,0,0])
-                    m4HexNutPocketNegative();
-        }
-    }
-}
-
-module _connectingLBracketRailSegment() {
-
-    difference() {
-        cube(size = [railOtherThickness, frontScrewSpacing + railOtherThickness, railTotalHeight]);
-
-        union () {
-            translate(v=[0,4,railFootThickness + screwDiff / 2])
-                rotate(a=[0,90,0])
-                    cylinder(r=m3RadiusSlacked, h = 10, $fn=32, center=true);
-
-            translate(v=[0,4,railTotalHeight-(railFootThickness + screwDiff / 2)])
-                rotate(a=[0,90,0])
-                    cylinder(r=m3RadiusSlacked, h = 10, $fn=32, center=true);
-        }
-    }
-
-    translate(v=[0, frontScrewSpacing + railOtherThickness, 0])
-    rotate(a=[0,0,270])
-        cube(size=[railOtherThickness, frontFaceWidth - sideSupportExtraSpace, railTotalHeight]);
-}
-
-
-module _sideSupportSegment() {
-
-    difference() {
-        cube(size=[sideSupportDepth, railSideMountThickness, railTotalHeight]);
-
-        for (i=[1:numRailScrews]) {
-            translate(v=[sideSupportScrewHoleToFrontEdge, railFrontThickness/2, i*screwDiff + railFootThickness])
-            rotate(a=[90,0,0])
-                    cylinder(r=m4RadiusSlacked, h=10, $fn=32);
-        }
-    }
-
-}
-
-module _railFeet() {
-
-    difference() {
-        cube(size = [frontFaceWidth - sideSupportExtraSpace, sideSupportDepth, railFootThickness]);
-
-        hull() {
-            translate(v = [1.5, 5, 0])
-                cylinder(r = m3RadiusSlacked, h = 10, $fn = 32);
-
-            translate(v = [0, 5, 0])
-            cube(size=[0.1, m3RadiusSlacked*2, 10], center=true);
-        }
-    }
-}
 
 module mainRail() {
-    union() {
 
+  // Distance between the middle of a screw mount and the rail's vertical edges
+
+  railScrewHoleToInnerEdge = 5;
+  railScrewHoleToOuterEdge = 5;
+
+  // Distance between the midpoint of the rail screw holes.
+  rackMountScrewWidth = maxUnitWidth + 2 * railScrewHoleToInnerEdge;
+
+  railFrontThickness = 6; // Make sure that the nuts for the chosen screw type can slot within the front face
+  railSideMountThickness = 2.5;
+  railOtherThickness = 2.5;
+
+
+  // Extra spacing for the rack unit screws.
+  frontScrewSpacing = 8;
+
+  sideSupportExtraSpace = 2;
+  sideSupportScrewHoleToFrontEdge = 5;
+  sideSupportScrewHoleToBackEdge = 4.5;
+  sideSupportDepth = sideSupportScrewHoleToBackEdge + sideSupportScrewHoleToFrontEdge;
+
+  frontFaceWidth = railScrewHoleToInnerEdge + railScrewHoleToOuterEdge;
+
+  union() {
     _frontRailSegment();
 
     translate(v = [0, railFrontThickness, 0])
     _connectingLBracketRailSegment();
 
-        translate(v = [frontFaceWidth-sideSupportExtraSpace, railFrontThickness + railOtherThickness + frontScrewSpacing, 0])
+    translate(v = [frontFaceWidth - sideSupportExtraSpace, railFrontThickness + railOtherThickness + frontScrewSpacing,
+      0])
     rotate(a = [0, 0, 90])
     _sideSupportSegment();
 
@@ -110,12 +50,72 @@ module mainRail() {
     translate(v = [0, railFrontThickness + railOtherThickness + frontScrewSpacing, 0]) {
       _railFeet();
 
-            translate(v = [0, 0, railTotalHeight-railFootThickness])
+      translate(v = [0, 0, railTotalHeight - railFootThickness])
       _railFeet();
     }
   }
+
+  module _frontRailSegment() {
+    difference() {
+      cube(size = [frontFaceWidth, railFrontThickness, railTotalHeight]);
+
+      for (i = [1:numRailScrews]) {
+        translate(v = [railScrewHoleToOuterEdge, railFrontThickness / 2, i * screwDiff + railFootThickness])
+        rotate(a = [90, 0, 0])
+        hexNutPocket_N(mainRailScrewType);
+      }
+    }
+  }
+
+  module _connectingLBracketRailSegment() {
+
+    difference() {
+      cube(size = [railOtherThickness, frontScrewSpacing + railOtherThickness, railTotalHeight]);
+
+      union() {
+        translate(v = [0, 4, railFootThickness + screwDiff / 2])
+        rotate(a = [0, 90, 0])
+        cylinder(r = screwRadiusSlacked(rackFrameScrewType), h = 10, $fn = 32, center = true);
+
+        translate(v = [0, 4, railTotalHeight - (railFootThickness + screwDiff / 2)])
+        rotate(a = [0, 90, 0])
+        cylinder(r = screwRadiusSlacked(rackFrameScrewType), h = 10, $fn = 32, center = true);
+      }
+    }
+
+    translate(v = [0, frontScrewSpacing + railOtherThickness, 0])
+    rotate(a = [0, 0, 270])
+    cube(size = [railOtherThickness, frontFaceWidth - sideSupportExtraSpace, railTotalHeight]);
+  }
+
+
+  module _sideSupportSegment() {
+
+    difference() {
+      cube(size = [sideSupportDepth, railSideMountThickness, railTotalHeight]);
+
+      for (i = [1:numRailScrews]) {
+        translate(v = [sideSupportScrewHoleToFrontEdge, railFrontThickness / 2, i * screwDiff + railFootThickness])
+        rotate(a = [90, 0, 0])
+        cylinder(r = screwRadiusSlacked(mainRailSideMountScrewType), h = 10, $fn = 32);
+      }
+    }
+
+  }
+
+  module _railFeet() {
+
+    difference() {
+      cube(size = [frontFaceWidth - sideSupportExtraSpace, sideSupportDepth, railFootThickness]);
+
+      hull() {
+        translate(v = [1.5, 5, 0])
+        cylinder(r = screwRadiusSlacked(rackFrameScrewType), h = 10, $fn = 32);
+
+        translate(v = [0, 5, 0])
+        cube(size = [0.1, screwRadiusSlacked(rackFrameScrewType) * 2, 10], center = true);
+      }
+    }
+  }
+
 }
-
-mainRail();
-
-echo("Total Rail Height = ", railTotalHeight);

cases/rack2/screws.scad

@@ -1,113 +1,80 @@
+/* Some common screw dimensions and helper functions/modules */
 
-/* Some common screw dimensions */
+inf = 400;
-
-
-inf = 400; // basically infinity
 
 /********************************************************************************/
 // M3 dimensions
-
 m3HoleRadiusSlack = 0.15;
 m3Diameter = 3.0;
-m3Radius = m3Diameter/2.0;
+m3Radius = m3Diameter / 2.0;
-
 m3RadiusSlacked = m3Radius + m3HoleRadiusSlack;
-
-// legacy TODO: replace
-m3ptr = m3RadiusSlacked;
-
-// NUTS!
 m3HexNutWidthAcrossFlats = 5.41;
 m3HexNutWidthAcrossCorners = FtoG(m3HexNutWidthAcrossFlats);
-
 m3HexNutThickness = 2.18;
 
-module m3HexNutPocketNegative() {
-  hexNutPocketNegative(m3RadiusSlacked,
-                       m3HexNutWidthAcrossCorners/2 + 0.1,
-                       m3HexNutThickness + 0.2);
-}
-
-
-// TODO: remove test
-
-*difference() {
-  cube(size=[8,12,5], center=true);
-
-  rotate(a=[0,0,20])
-  m3HexNutPocketNegative();
-}
-
-*m3HexNutPocketNegative();
-
-
 /********************************************************************************/
 // M4 dimensions
-
 m4HoleRadiusSlack = 0.15;
 m4Diameter = 4.0;
-m4Radius = m4Diameter/2.0;
+m4Radius = m4Diameter / 2.0;
 m4RadiusSlacked = m4Radius + m4HoleRadiusSlack;
-
 m4HexNutWidthAcrossFlats = 6.89;
 m4HexNutWidthAcrossCorners = FtoG(m4HexNutWidthAcrossFlats);
-
 m4HexNutThickness = 3.07;
 
-module m4HexNutPocketNegative() {
-  hexNutPocketNegative(m4RadiusSlacked,
-                       m4HexNutWidthAcrossCorners/2 + 0.1,
-                       m4HexNutThickness + 0.2);
-}
-
-
-// TODO: remove test
-
-*difference() {
-  translate(v=[0,1,0])
-  cube(size=[10,12,6], center=true);
-
-  rotate(a=[0,0,20])
-  m4HexNutPocketNegative();
-}
-
-*m4HexNutPocketNegative();
-
 /********************************************************************************/
-
+function screwRadiusSlacked(screwType) =
-// Convert a regular hexagon widthAcrossFlats to widthAcrossCorners
+  (screwType == "m3")
-function FtoG(widthAcrossFlats) = widthAcrossFlats * (2/sqrt(3));  
+  ? m3RadiusSlacked
-
+  : (screwType == "m4")
-// Convert a regular hexagon widthAcrossCorners to widthAcrossFlats
+  ? m4RadiusSlacked
-function GtoF(widthAcrossCorners) =  widthAcrossCorners * (sqrt(3)/2);
+  : error("Unsupported screw type");
 
 
-module hexNutPocketNegative(
+module hexNutPocket_N(screwType) {
-  innerRadius,
+  if (screwType == "m3") {
-  widthAcrossCorners,
+    hexNutPocketHelper_N(m3RadiusSlacked,
-  thickness)
+        m3HexNutWidthAcrossCorners / 2 + 0.1,
+      m3HexNutThickness + 0.2);
+  } else if (screwType == "m4") {
+    hexNutPocketHelper_N(m4RadiusSlacked,
+        m4HexNutWidthAcrossCorners / 2 + 0.1,
+      m4HexNutThickness + 0.2);
+  } else {
+    error("Unsupported screw type");
+  }
+}
+
+module hexNutPocketHelper_N(
+innerRadius,
+widthAcrossCorners,
+thickness)
 {
-
   union() {
 
     hull() {
       // hexagonal cylinder representing where the nut should fit
-      cylinder(r=widthAcrossCorners, h=thickness, center=true, $fn=6);
+      cylinder(r = widthAcrossCorners, h = thickness, center = true, $fn = 6);
 
       // negative volume for sliding in the nut
-      translate(v=[inf,0,0])
+      translate(v = [inf, 0, 0])
-      cylinder(r=widthAcrossCorners, h=thickness, center=true, $fn=6);
+      cylinder(r = widthAcrossCorners, h = thickness, center = true, $fn = 6);
     }
 
     // negative volume for screw lead
-    translate(v=[0,0,-10])
+    translate(v = [0, 0, - 10])
-    cylinder(r=innerRadius, h = inf, $fn=32);
+    cylinder(r = innerRadius, h = inf, $fn = 32);
 
     hull() {
-     translate(v=[inf,0,0])
+      translate(v = [inf, 0, 0])
-       cylinder(r=innerRadius, h = inf, $fn=32);
+      cylinder(r = innerRadius, h = inf, $fn = 32);
-     cylinder(r=innerRadius, h = inf, $fn=32);
+      cylinder(r = innerRadius, h = inf, $fn = 32);
     }
   }
 }
 
+// Convert a regular hexagon widthAcrossFlats to widthAcrossCorners
+function FtoG(widthAcrossFlats) = widthAcrossFlats * (2 / sqrt(3));
+
+// Convert a regular hexagon widthAcrossCorners to widthAcrossFlats
+function GtoF(widthAcrossCorners) = widthAcrossCorners * (sqrt(3) / 2);