diff --git a/v1/scad/lib/hexagon.scad b/v1/scad/lib/hexagon.scad
new file mode 100644
index 0000000..8a72667
--- /dev/null
+++ b/v1/scad/lib/hexagon.scad
@@ -0,0 +1,5 @@
+module hexagon(inradius) {
+    circle(r=2 * inradius / sqrt(3), $fn=6);
+}
+
+hexagon(inradius=2.8);
\ No newline at end of file
diff --git a/v1/scad/lib/prusa_enclosure_mount.scad b/v1/scad/lib/prusa_enclosure_mount.scad
index c510f65..d1e75a5 100644
--- a/v1/scad/lib/prusa_enclosure_mount.scad
+++ b/v1/scad/lib/prusa_enclosure_mount.scad
@@ -1,4 +1,5 @@
 use <spoolmount_a.scad>
+use <screw_hole.scad>
 use <torus.scad>
 
 module prusa_enclosure_mount(angle) {
@@ -25,20 +26,8 @@ module prusa_enclosure_mount(angle) {
                     }
                     
                     // Through screw hole
-                    translate([120, 0, -1])
-                    cylinder(h=20, d=3.2, $fn=50);
-                    
-                    // Hex nut / screw head cutout 
-                    translate([120, 0, 18 - (2.6 / 2)])
-                    linear_extrude(2.61, center=true)
-                    polygon(points=[
-                        [-2.8, 1.6175],
-                        [0, 3.235],
-                        [2.8, 1.6175],
-                        [2.8, -1.6175],
-                        [0, -3.235],
-                        [-2.8, -1.6175],
-                    ]);
+                    translate([120, 0, 0])
+                    screw_hole(h=18);
 
                     // Underside washer alignment cutouts
                     for (y = [-4, 4]) {
@@ -68,15 +57,15 @@ module prusa_enclosure_mount(angle) {
                     union() {
                         // Top core
                         translate([0, 0, 2.5])
-                        cylinder(h=15.5, r=42, $fn=200);
+                        cylinder(h=15, r=42, $fn=200);
 
                         // Bottom core
-                        cylinder(h=18, r=40.25, $fn=200);
+                        cylinder(h=5, r=40.25, $fn=200);
                     }
 
                     // Center through cutout
                     translate([0, 0, -1])
-                    cylinder(h=20, r=25, $fn=200);
+                    cylinder(h=20, r=25.1, $fn=200);
 
                     // Bottom cutout
                     translate([0, 0, -1])
@@ -93,6 +82,18 @@ module prusa_enclosure_mount(angle) {
             }
         }
 
+        // Spool ring weight reduction holes
+        for (a = [0 : 20 : 340]) {
+            rotate([0, 0, a])
+            translate([0, 33, 0]) {
+                translate([0, 0, -1])
+                cylinder(h=9.5, d=9, $fn=50);
+
+                translate([0, 0, 8.49])
+                cylinder(h=4.5, d1=9, d2=0, $fn=50);
+            }
+        }
+
         // Weight reduction holes rows 1/5
         for (x = [44.5 : 12 : 105]) {
             for (y = [-20 : 40 : 20]) {
diff --git a/v1/scad/lib/screw_hole.scad b/v1/scad/lib/screw_hole.scad
new file mode 100644
index 0000000..fff7e9d
--- /dev/null
+++ b/v1/scad/lib/screw_hole.scad
@@ -0,0 +1,30 @@
+use <hexagon.scad>
+
+module screw_hole(h) {
+    // Through screw hole
+    translate([0, 0, -0.01])
+    cylinder(h=h, d=3.2, $fn=50);
+
+    // Hex nut cutout 
+    translate([0, 0, h - 3])
+    hull() {
+        // Large hex nut
+        translate([0, 0, 3])
+        linear_extrude(0.01)
+        hexagon(inradius=2.8);
+
+        // Small hex nut
+        linear_extrude(0.01)
+        hexagon(inradius=2.55);
+    }
+
+    // Screw head cutout
+    translate([0, 0, h - 3])
+    cylinder(h=2.61, d=5.5, $fn=50);
+
+    // Bottom screw thread protrusion cutout
+    translate([0, 0, -0.01])
+    cylinder(h=1.01, d=4.4, $fn=100);
+}
+
+screw_hole(h=10);
\ No newline at end of file
diff --git a/v1/scad/objects/ptfe_guide.scad b/v1/scad/objects/ptfe_guide.scad
index a1bbbcb..0d7f197 100644
--- a/v1/scad/objects/ptfe_guide.scad
+++ b/v1/scad/objects/ptfe_guide.scad
@@ -1,3 +1,5 @@
+use <../lib/screw_hole.scad>
+
 module ptfe_guide() {
     translate([0, 0, 5])
     difference() {
@@ -13,27 +15,8 @@ module ptfe_guide() {
         }
 
         // Screw hole
-        {
-            // Top hex nut / screw cap head cutout
-            translate([0, 0, 3.7])
-            linear_extrude(2.61, center=true)
-            polygon(points=[
-                [-2.8, 1.6175],
-                [0, 3.235],
-                [2.8, 1.6175],
-                [2.8, -1.6175],
-                [0, -3.235],
-                [-2.8, -1.6175],
-            ]);
-
-            // Through hole
-            translate([0, 0, 0])
-            cylinder(h=10, d=3.2, center=true, $fn=100);
-
-            // Bottom screw thread protrusion cutout
-            translate([0, 0, -4.5])
-            cylinder(h=1.01, d=4.4, center=true, $fn=100);
-        }
+        translate([0, 0, -5])
+        screw_hole(10);
 
         // PTFE holes
         for (x = [-18, -10, 10, 18]) {