diff --git a/gear-v3.scad b/gear-v3.scad
index 7e03d84..3d7d3d8 100644
--- a/gear-v3.scad
+++ b/gear-v3.scad
@@ -63,29 +63,25 @@ translate([0, 0, 16])
 
 /* 2-stud-thick variant of 32-teeth ring gear */
 
-ring_gear_2u_32t();
+//ring_gear_2u_32t();
 
 /* Standard 8-teeth gear */
 
 //std_gear8();
 
-/* Planetary ring gear with both inner and outer 40 teeth */
+/* 40-teeth (both inside and outside) planetary ring gear */
 
 //planetary_ring_gear(plane_height=1);
 
-/* 40-teeth planetary ring gear with clutch */
-
-//planetary_ring_gear_with_clutch();
-
 /* Solid clutch gear, like standard 16-teeth */
 
 //clutchGear(32);
 
-/* Gear with clutch fully offset to one side */
+/* Gear with clutch fully offset to one side - useful for compact gearbox */
 
-//offsetClutchGear(16);
+//offsetClutchGear(23);
 
-/* Gear with bearing only at one side */
+/* Gear fully offset to one side */
 
 //offsetGear(number_of_teeth=8, gear_height=3.8);
 // Sample offset gear with 28 teeth and 4 holes
@@ -93,7 +89,7 @@ ring_gear_2u_32t();
 
 /* Gear with offset teeth, axle hole and sparse body */
 
-//offsetGearSparse(20, gear_height=3.9);
+offsetGearSparse(9, gear_height=3.9);
 
 /* Half-stud parametric gear with some holes */
 
@@ -351,52 +347,6 @@ module std_gear8() {
     axle(0, 0, -1, 10);
 }}
 
-module planetary_ring_gear_with_clutch() {
-  union() {
-    difference() {
-      cylinder($fn=100, h=8, r=22);
-      // make inner gear slightly bigger
-      translate([0, 0, -0.1]) gear(mm_per_tooth=3.1415926, number_of_teeth=40, thickness=6.1);
-      cylinder($fn=100, h=8.1, r=19);
-    }
-    translate([0, 0, 8])
-    difference() {
-      union() {
-        cylinder($fn=100, h=2, r=(0.1+3.1*(40/2+1)/3.1415926));
-        translate([0, 0, 2]) gear(mm_per_tooth=3.1, number_of_teeth=40, thickness=4, clearance=-0.1);
-        translate([0, 0, 5]) cylinder($fn=100, h=2.2, r=(3.1*(40/2-1)/3.1415926));
-        cylinder($fn=100, h=8, r=6.8);
-      }
-      translate([0, 0, 4]) difference() {
-        translate([0, 0, -0.1]) cylinder($fn=100, h=20, r=5.8);
-        translate([0, 0, -0.1]) cylinder($fn=100, h=20.2, r=3.5);
-      }
-      translate([0, 0, -0.1]) difference() {
-        cylinder($fn=100, h=8.2, r=(3.1*(40/2-1)/3.1415926)-1);
-        translate([0, 0, 3.5]) cylinder($fn=100, h=1, r=(3.1*(40/2-1)/3.1415926)-1);
-        translate([0, 0, -0.1]) cylinder($fn=100, h=10, r=6.8);
-        translate([-0.5, -20, -0.1]) cube(size=[1, 40, 10]);
-        translate([-20, -0.5, -0.1]) cube(size=[40, 1, 10]);
-/*        translate([-10, 8-0.5, -0.1]) cube(size=[20, 1, 10]);
-        translate([-10, -8-0.5, -0.1]) cube(size=[20, 1, 10]);
-        translate([8-0.5, -10, -0.1]) cube(size=[1, 20, 10]);
-        translate([-8-0.5, -10, -0.1]) cube(size=[1, 20, 10]);
-        rotate([0, 0, -45]) translate([-0.5, 10, -0.1]) cube(size=[1, 10, 10]);
-        rotate([0, 0, 45]) translate([-0.5, 10, -0.1]) cube(size=[1, 10, 10]);
-        rotate([0, 0, -135]) translate([-0.5, 10, -0.1]) cube(size=[1, 10, 10]);
-        rotate([0, 0, 135]) translate([-0.5, 10, -0.1]) cube(size=[1, 10, 10]);*/
-      }
-      translate([0, 0, -0.1]) cylinder($fn=100, h=10, r=2.5);
-    }
-    translate([0, 0, 10.2]) union() {
-      clutchTeeth();
-      rotate([0, 0, 90]) clutchTeeth();
-      rotate([0, 0, 180]) clutchTeeth();
-      rotate([0, 0, -90]) clutchTeeth();
-    }
-  }
-}
-
 // Planetary ring gear, 2 stud thick, sparse
 module planetary_ring_gear(plane_height = 1) {
   union() {
@@ -503,22 +453,26 @@ module offsetGear(number_of_teeth, gear_height=3.9) {
 
 // Gear with interface for driving ring, with offset teeth
 // => The minimal printable size of such gear is 9 teeth...
-// (8 teeth will probably be too thin in some places)
+// (8 teeth will probably be too thin at root circle)
 module offsetClutchGear(number_of_teeth) {
   union() {
     difference() {
       union() {
-        gear(number_of_teeth=number_of_teeth, mm_per_tooth=3.05, thickness=3.9);
-        translate([0, 0, 3.9]) cylinder($fn=100, h=4.1, r=6.8);
+        gear(number_of_teeth=number_of_teeth, mm_per_tooth=3.05, thickness=4);
+        translate([0, 0, 3.9]) cylinder($fn=max(32,2*number_of_teeth), h=4.1, r=6.8);
       }
       difference() {
-        translate([0, 0, 4.8]) cylinder($fn=100, h=4, r=5.8);
-        translate([0, 0, 4.8]) cylinder($fn=100, h=4, r=3.3);
+        translate([0, 0, 4.8]) cylinder($fn=50, h=4, r=5.8);
+        translate([0, 0, 4.8]) cylinder($fn=50, h=4, r=3.3);
+      }
+      difference() {
+        translate([0, 0, -0.1]) cylinder($fn=50, h=2.9+0.1, r=3.05*(number_of_teeth/2-1)/3.1415926-1);
+        translate([0, 0, -0.2]) cylinder($fn=50, h=4, r=3.5);
+        translate([-0.5, -20, -0.1]) cube(size=[1, 40, 10]);
+        translate([-20, -0.5, -0.1]) cube(size=[40, 1, 10]);
       }
       // round hole
-      translate([0, 0, -3]) cylinder($fn=100, h=12, r=2.5);
-      // axle hole
-      //axle(0, 0, -1, 10);
+      translate([0, 0, -2]) cylinder($fn=50, h=12, r=2.5);
     }
     translate([0, 0, 3]) union() {
       clutchTeeth();