diff --git a/scad/jk_projector_knob.scad b/scad/jk_projector_knob.scad
index d162d51..8bcf525 100644
--- a/scad/jk_projector_knob.scad
+++ b/scad/jk_projector_knob.scad
@@ -1,20 +1,34 @@
 
 // THREAD
-// 
+// 1/4" 20 (coarse)
 
-module jk_projector_knob () {
+module hex (diag = 10, h = 1) {
+    cylinder(r = diag / 2, h = h, center = true, $fn = 6);
+}
+
+module jk_projector_knob_positive () {
     $fn = 120;
     count = 3;
-    cylinder(r = 15 / 2, h = 22, center = true);
+    cylinder(r = 16 / 2, h = 22, center = true);
     for (i = [0 : count - 1]) {
-        rotate([0, 0, i * (360 / count) ])    translate([0, 8, -3]) difference () {
+        rotate([0, 0, i * (360 / count) ])    translate([0, 8+3, -3]) difference () {
             cube([9, 16, 16], center = true);
-            translate([0, 8, 6]) rotate([-45, 0, 0]) cube([9 + 1, 20, 16], center = true);
-          translate([8, 0, 0]) rotate([0, 0, 15]) cube([9, 20, 16+ 1], center = true);
-          translate([-8, 0, 0]) rotate([0, 0, -15]) cube([9, 20, 16+ 1], center = true);
+            translate([0, 8, 6]) rotate([-45, 0, 0]) cube([9 + 1, 16*2, 16], center = true);
+          translate([8, 0, 0]) rotate([0, 0, 10]) cube([9, 20, 16+ 1], center = true);
+          translate([-8, 0, 0]) rotate([0, 0, -10]) cube([9, 20, 16+ 1], center = true);
         }
         
     }
 }
+//20-12
+module jk_projector_knob () {
+    difference () {
+        jk_projector_knob_positive();
+        translate([0, 0, -(22 - 12)]) rotate([0, 0, 30]) hex(13.5, 22);
+         cylinder(r = 6.3 / 2, h = 22 + 1, center = true, $fn = 50);
+    }
+}
+
+//hex(13 - .5, 11-4.5);
 
 jk_projector_knob();
\ No newline at end of file