move screws.scad

2023-01-12 00:07:02 -05:00
parent 233bdf3145
commit 0b05249d7b
7 changed files with 9 additions and 8 deletions
--- a/helper/screws.scad
+++ b/helper/screws.scad
@ -0,0 +1,97 @@
+/* Some common screw dimensions and helper functions/modules */
+
+include <./math.scad>
+include <./common.scad>
+
+/********************************************************************************/
+// M3 dimensions
+m3HoleRadiusSlack = 0.4; // higher slack for not-so straight heat set inserts
+m3Diameter = 3.0;
+m3Radius = m3Diameter / 2.0;
+m3RadiusSlacked = m3Radius + m3HoleRadiusSlack;
+
+m3HexNutWidthAcrossFlats = 5.41;
+m3HexNutWidthAcrossCorners = FtoG(m3HexNutWidthAcrossFlats);
+m3HexNutThickness = 2.18;
+
+m3HeatSetInsertSlotRadiusSlack = -0.1;
+m3HeatSetInsertSlotHeightSlack = 0.5;
+
+m3HeatSetInsertSlotRadius = 2.5;
+m3HeatSetInsertSlotHeight = 6;
+
+m3HeatSetInsertSlotRadiusSlacked = m3HeatSetInsertSlotRadius+m3HeatSetInsertSlotRadiusSlack;
+m3HeatSetInsertSlotHeightSlacked = m3HeatSetInsertSlotHeight+m3HeatSetInsertSlotHeightSlack;
+
+/********************************************************************************/
+// M4 dimensions
+m4HoleRadiusSlack = 0.15;
+m4Diameter = 4.0;
+m4Radius = m4Diameter / 2.0;
+m4RadiusSlacked = m4Radius + m4HoleRadiusSlack;
+m4HexNutWidthAcrossFlats = 6.89;
+m4HexNutWidthAcrossCorners = FtoG(m4HexNutWidthAcrossFlats);
+m4HexNutThickness = 3.07;
+
+/********************************************************************************/
+
+module heatSetInsertSlot_N(screwType) {
+  if (screwType == "m3") {
+    union() {
+      // actual slot for insert
+      cylinder(h = m3HeatSetInsertSlotHeightSlacked, r = m3HeatSetInsertSlotRadiusSlacked);
+
+      // extra space above slot to help with insertion
+      translate(v=[0, 0, m3HeatSetInsertSlotHeightSlacked])
+      cylinder(h = inf50, r = 1.3*m3HeatSetInsertSlotRadiusSlacked);
+    }
+  } else {
+    error("Unsupported screw type");
+  }
+}
+
+function screwRadiusSlacked(screwType) =
+  (screwType == "m3")
+  ? m3RadiusSlacked
+  : (screwType == "m4")
+  ? m4RadiusSlacked
+  : error("Unsupported screw type");
+
+module hexNutPocket_N(screwType) {
+  if (screwType == "m3") {
+    hexNutPocketHelper_N(m3RadiusSlacked, 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);
+
+      // negative volume for sliding in the nut
+      translate(v = [inf50, 0, 0])
+      cylinder(r = widthAcrossCorners, h = thickness, center = true, $fn = 6);
+    }
+
+    // negative volume for screw lead
+    translate(v = [0, 0, - 10])
+    cylinder(r = innerRadius, h = inf50, $fn = 32);
+
+    hull() {
+      translate(v = [inf50, 0, 0])
+      cylinder(r = innerRadius, h = inf50, $fn = 32);
+      cylinder(r = innerRadius, h = inf50, $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);