add filets

helper/filet.scad

@@ -0,0 +1,42 @@
+include <./halfspace.scad>
+include <./math.scad>
+
+// Some modules for simple subtractive filets
+
+module cylindricalFiletNegative(p0, p1, n, r) {
+  l = norm(p1-p0);
+
+  align_to(p0=p0, p1=p1, p2=p0-n)
+  rotate(a=[45,0,0])
+  rotate(a=[0,90,0])
+  zFiletNegative(length = l, r = r);
+}
+
+module zFiletNegative(length, r) {
+
+  p1 = [0,0,0];
+  p2 = [0,0,length];
+  n1 = [-1,-1,0] / norm([-1,-1,0]);
+  dr = sqrt(2*r^2);
+
+  difference() {
+
+    hull() {
+      translate(v=[0,0,0])
+      cube(size=[r,r,r]);
+
+      translate(v = p2-[0,0,0.1])
+      cube(size=[r,r,0.1]);
+
+    }
+
+    hull() {
+      translate(v = p1-n1*dr)
+      cylinder(r = r, h=0.0001, $fn = 32);
+
+
+      translate(v = p2-n1*dr)
+      cylinder(r = r, h=0.0001, $fn = 32);
+    }
+  }
+}