add screw

1 files changed, 35 insertions, 3 deletions

diff --git a/gimbal.scad b/gimbal.scad
index 192cc54..ff13158 100644
--- a/gimbal.scad
+++ b/gimbal.scad
@@ -4,8 +4,9 @@ cutoff = 3;
 c = 3;
 base = 10;
 
-screw_len = 0.8 * (d - 2*cutoff);
+screw_len = 15;
 screw_dia = 25.4/4;
+screw_head_len = 5;
 
 mount_screw_dia = 4;
 mount_screw_head_dia = 10;
@@ -16,10 +17,29 @@ retainer_dia = 1;
 e = 0.01;
 $fn = 500;
 
+use <simplethreads.scad>;
+
 module screw() {
-    cylinder(r=screw_dia/2, h=screw_len);
+    translate([0, 0, 2*screw_head_len - screw_dia/2])
+    thread_imperial(1/16, screw_dia/25.4, 12, screw_len*16/25.4);
+
+    intersection() {
+	cylinder(r1=2*screw_head_len, r2=0, h=2*screw_head_len);
+	cube([2*screw_head_len, 2*screw_head_len, 10*screw_head_len], center=true);
+    }
 }
 
+module two_half_screws()
+    for (i = [0,1])
+    translate([i*2*screw_head_len, -i*(screw_len + screw_head_len), 0])
+    intersection() {
+	rotate([90, i*180, i*180])
+	screw();
+
+	translate([0, 0, 50])
+	cube(100, center=true);
+    }
+
 module grip()
     for (i = [0:19])
         rotate(i*360/20)
@@ -28,11 +48,23 @@ module grip()
 
 module ball()
     difference() {
+	// sphere with top and bottom cap removed
 	sphere(d/2);
-	translate([0, 0, d/2 - cutoff - screw_len + e]) screw();
 	for (i = [-1,1])
             translate([0, 0, i * (d - cutoff)]) cube(d, center=true);
 
+	// screw hole (thin ot the top, thickening in the center, big
+	// square at the bottom)
+	translate([0, 0, d/2 - cutoff - screw_len/2 + screw_head_len/2]) {
+	    cylinder(r=screw_dia/2, h=d, center=true);
+
+	    mirror([0, 0, 1])
+	    intersection() {
+		cylinder(r1=0, r2=d, h=d);
+		cube([2*screw_head_len, 2*screw_head_len, 10*screw_head_len], center=true);
+	    }
+	}
+
 	// horizontal grip
 	grip();
 	// vertical grip at the upper half sphere (but not at the top)