diff --git a/gear-v3.scad b/gear-v3.scad
index 9776c3a..e5ac0e3 100644
--- a/gear-v3.scad
+++ b/gear-v3.scad
@@ -36,8 +36,10 @@
 // Thickness of all gear wheels is 3.8mm
 // Standard 40t gear: root_radius=18.75 outer_radius=20.85 (mm_per_tooth =~ 3.1 by root)
 // Standard 24t gear: root_radius=10.7 outer_radius=12.8 (mm_per_tooth =~ 3.06 by root)
-// Standard 16t gear: root_radius=6.8 outer_radius=7.9 (mm_per_tooth =~ 3.05 by root)
+// Standard 16t gear: root_radius=6.8 outer_radius=8.7 (mm_per_tooth =~ 3.05 by root)
 // Standard 8t gear: root_radius=2.8 outer_radius=4.9 (mm_per_tooth =~ 3.05 by root)
+// Standard 12t bevel gear: 12.7mm bottom diameter, 1.6mm top teeth length, 10.6mm top teeth outer diameter, 7.7mm top teeth root diameter, 2.5mm gear height + 0.5mm flat base + 1mm spacer at bottom
+// Standard 20t idler bevel gear: 20.4mm bottom diameter, 18.4mm top teeth outer diameter, 1.8mm top teeth length, 15.6mm top teeth root diameter
 
 // Formulas for gear radiuses:
 //outer_radius = mm_per_tooth*(n_teeth/2+1)/3.1415926 - clearance;
@@ -55,15 +57,21 @@
 satellites_32t();
 translate([0, 0, -8])
   color([0.5, 1, 1, 1])
-  carrier_32t_simpler();
-translate([0, 0, 16])
+  carrier_32t_easy();
+translate([20, 0, 0])
+  color([1, 0.5, 0.5, 1])
+  rotate([0, 0, -22.5]) std_gear8();
+/*translate([0, 0, 16])
   rotate([0, 180, 0])
   color([0.5, 1, 0.5, 1])
   sun_drive_32t();*/
 
-/* 2-stud-thick variant of 32-teeth ring gear */
+/* 1-stud/2-stud thick variants of 32-teeth ring gear */
 
-//ring_gear_2u_32t();
+//ring_gear_1u_32t();
+ring_gear_2u_32t();
+//carrier_32t_not_so_easy();
+//sun_drive_32t_simpler();
 
 /* Standard 8-teeth gear */
 
@@ -97,11 +105,11 @@ translate([0, 0, 16])
 
 /* Half-stud parametric gear with some holes */
 
-//myGear(24);
+//myGear(16);
 
 /* Generic gear with involute teeth */
 
-//gear(mm_per_tooth=3.05, number_of_teeth=24, thickness=3.8, clearance=-0.1);
+//gear(mm_per_tooth=3.05, number_of_teeth=16, thickness=4, pressure_angle=20);
 
 /* Same, but using an experimental OpenSCAD feature - vector concat() function */
 
@@ -109,44 +117,27 @@ translate([0, 0, 16])
 
 //-------------
 
-// Same as carrier_32t(), but with axle hole at the center
+// Same as carrier_32t(), but solid with axle hole
 module sun_drive_32t() {
   root = 3.06*(32/2-1)/3.1415926;
   segments = 32*2; // so gear teeth edge never match cylinder segment edges
   difference() {
     union() {
-      difference() {
-        translate([0, 0, 2]) gear_teeth(mm_per_tooth=3.06, number_of_teeth=32, thickness=4, clearance=-0.1);
-        cylinder($fn=100, h=8, r=root-0.5);
-      }
-      cylinder($fn=100, h=8, r=3.5);
-      difference() {
-        union() {
-          difference() {
-            translate([0, 0, 0.8-0.1]) cylinder($fn=32*2, h=7.2+0.1, r=root);
-            translate([0, 0, -0.1]) cylinder($fn=32*2, h=7.1, r=root-1);
-          }
-          translate([-8, 0, 0.1]) cylinder($fn=32, h=8-0.2, r=3.5);
-          translate([0, -8, 0.1]) cylinder($fn=32, h=8-0.2, r=3.5);
-          translate([0, 8, 0.1]) cylinder($fn=32, h=8-0.2, r=3.5);
-          translate([8, 0, 0.1]) cylinder($fn=32, h=8-0.2, r=3.5);
-          translate([-0.5, -root+0.5, 0]) cube(size=[1, root*2-1, 8]);
-          rotate([0, 0, 90]) translate([-0.5, -root+0.5, 0]) cube(size=[1, root*2-1, 8]);
-        }
-        translate([-20, -20, -0.2]) cube(size=[40, 40, 1]);
-      }
+      translate([0, 0, 2]) gear_teeth(mm_per_tooth=3.06, number_of_teeth=32, thickness=4, pressure_angle=20);
+      cylinder($fn=100, h=7.2, r=root);
+      cylinder($fn=100, h=8, r=3.6);
     }
     rotate([0, 0, 45]) axleCut(0, 0, -0.2, 10);
 
-    translate([-8, 0, -0.2]) cylinder($fn=32, h=10, r=2.5);
-    translate([0, -8, -0.2]) cylinder($fn=32, h=10, r=2.5);
-    translate([0, 8, -0.2]) cylinder($fn=32, h=10, r=2.5);
-    translate([8, 0, -0.2]) cylinder($fn=32, h=10, r=2.5);
+    translate([-8, 0, -0.2]) cylinder($fn=32, h=10, r=2.55);
+    translate([0, -8, -0.2]) cylinder($fn=32, h=10, r=2.55);
+    translate([0, 8, -0.2]) cylinder($fn=32, h=10, r=2.55);
+    translate([8, 0, -0.2]) cylinder($fn=32, h=10, r=2.55);
 
-    translate([-8, 0, 7.2]) cylinder($fn=32, h=0.8+0.1, r=3);
-    translate([0, -8, 7.2]) cylinder($fn=32, h=0.8+0.1, r=3);
-    translate([0, 8, 7.2]) cylinder($fn=32, h=0.8+0.1, r=3);
-    translate([8, 0, 7.2]) cylinder($fn=32, h=0.8+0.1, r=3);
+    translate([-8, 0, -0.1]) cylinder($fn=32, h=1+0.1, r=3);
+    translate([0, -8, -0.1]) cylinder($fn=32, h=1+0.1, r=3);
+    translate([0, 8, -0.1]) cylinder($fn=32, h=1+0.1, r=3);
+    translate([8, 0, -0.1]) cylinder($fn=32, h=1+0.1, r=3);
   }
 }
 
@@ -156,63 +147,55 @@ module sun_drive_32t_simpler() {
   union() {
     difference() {
       union() {
+        gear_teeth(mm_per_tooth=3.06, number_of_teeth=32, thickness=7.2, pressure_angle=20);
         difference() {
-          translate([0, 0, 2]) gear_teeth(mm_per_tooth=3.06, number_of_teeth=32, thickness=4, clearance=-0.1);
-          cylinder($fn=100, h=8, r=root-0.5);
+          cylinder($fn=32*2, h=7.2, r=root);
+          translate([0, 0, 1]) cylinder($fn=32*2, h=7.1, r=root-2);
         }
-        difference() {
-          translate([0, 0, 0.8]) cylinder($fn=32*2, h=7.2, r=root);
-          translate([0, 0, -0.1]) cylinder($fn=32*2, h=7.1, r=root-1);
-        }
-        cylinder($fn=100, h=8, r=3.5);
+        cylinder($fn=100, h=8, r=1.95+2);
         union() {
-          translate([-0.5, -root+0.5, 0.8]) cube(size=[1, root*2-1, 6.4]);
-          rotate([0, 0, 90]) translate([-0.5, -root+0.5, 0.8]) cube(size=[1, root*2-1, 6.4]);
+          translate([-1, -root+0.5, 0.8]) cube(size=[2, root*2-1, 6.4]);
+          rotate([0, 0, 90]) translate([-1, -root+0.5, 0.8]) cube(size=[2, root*2-1, 6.4]);
         }
       }
-      rotate([0, 0, 45]) axleCut(0, 0, -0.2, 10);
+      rotate([0, 0, 45]) axle(0, 0, -0.2, 10);
     }
   }
 }
 
-// Simpler planetary carrier
-module carrier_32t_simpler() {
-  root = 3.06*(32/2-1)/3.1415926;
-  segments = 32*2; // so gear teeth edge never match cylinder segment edges
+// Symmetric planetary carrier gear (not so easy to print because it needs support)
+module carrier_32t_not_so_easy() {
+  root = 3.1*(32/2-1)/3.1415926;
+  fn = 32*2; // so gear teeth edge never match cylinder segment edges
   difference() {
     union() {
-      difference() {
-        translate([0, 0, 2]) gear_teeth(mm_per_tooth=3.06, number_of_teeth=32, thickness=4, clearance=-0.1);
-        cylinder($fn=100, h=8, r=root-0.5);
-      }
-      cylinder($fn=100, h=8, r=3.5);
-      difference() {
-        union() {
-          difference() {
-            translate([0, 0, 0.8-0.1]) cylinder($fn=32*2, h=7.2+0.1, r=root);
-            translate([0, 0, -0.1]) cylinder($fn=32*2, h=7.1, r=root-1);
-          }
-          translate([-8, 0, 0.1]) cylinder($fn=32, h=8-0.2, r=3.5);
-          translate([0, -8, 0.1]) cylinder($fn=32, h=8-0.2, r=3.5);
-          translate([0, 8, 0.1]) cylinder($fn=32, h=8-0.2, r=3.5);
-          translate([8, 0, 0.1]) cylinder($fn=32, h=8-0.2, r=3.5);
-          translate([-0.5, -root+0.5, 0]) cube(size=[1, root*2-1, 8]);
-          rotate([0, 0, 90]) translate([-0.5, -root+0.5, 0]) cube(size=[1, root*2-1, 8]);
-        }
-        translate([-20, -20, -0.2]) cube(size=[40, 40, 1]);
-      }
+      translate([0, 0, 2]) gear_teeth(mm_per_tooth=3.1, number_of_teeth=32, thickness=4, pressure_angle=20);
+      translate([0, 0, 0.8]) cylinder($fn=fn, r=root, h=6.4);
+      cylinder($fn=32, r=2.4+0.15+1.2, h=8);
     }
-    translate([0, 0, -0.2]) cylinder($fn=32, h=10, r=2.5);
+    translate([0, 0, -0.2]) cylinder($fn=32, h=10, r=2.4+0.15);
+    translate([-8, 0, -0.2]) cylinder($fn=32, h=10, r=2.4+0.15);
+    translate([0, -8, -0.2]) cylinder($fn=32, h=10, r=2.4+0.15);
+    translate([0, 8, -0.2]) cylinder($fn=32, h=10, r=2.4+0.15);
+    translate([8, 0, -0.2]) cylinder($fn=32, h=10, r=2.4+0.15);
+  }
+}
 
-    translate([-8, 0, -0.2]) cylinder($fn=32, h=10, r=2.5);
-    translate([0, -8, -0.2]) cylinder($fn=32, h=10, r=2.5);
-    translate([0, 8, -0.2]) cylinder($fn=32, h=10, r=2.5);
-    translate([8, 0, -0.2]) cylinder($fn=32, h=10, r=2.5);
-
-    translate([-8, 0, 7.2]) cylinder($fn=32, h=0.8+0.1, r=3);
-    translate([0, -8, 7.2]) cylinder($fn=32, h=0.8+0.1, r=3);
-    translate([0, 8, 7.2]) cylinder($fn=32, h=0.8+0.1, r=3);
-    translate([8, 0, 7.2]) cylinder($fn=32, h=0.8+0.1, r=3);
+// Easy to print planetary carrier gear
+module carrier_32t_easy() {
+  root = 3.1*(32/2-1)/3.1415926;
+  fn = 32*2; // so gear teeth edge never match cylinder segment edges
+  difference() {
+    union() {
+      gear_teeth(mm_per_tooth=3.1, number_of_teeth=32, thickness=6.4, pressure_angle=20);
+      cylinder($fn=fn, r=root, h=6.4);
+      cylinder($fn=32, r=2.4+0.15+1.2, h=7.2); // 1.2 = 0.4(nozzle)*3 perimeters
+    }
+    translate([0, 0, -0.2]) cylinder($fn=32, h=10, r=2.4+0.15);
+    translate([-8, 0, -0.2]) cylinder($fn=32, h=10, r=2.4+0.15);
+    translate([0, -8, -0.2]) cylinder($fn=32, h=10, r=2.4+0.15);
+    translate([0, 8, -0.2]) cylinder($fn=32, h=10, r=2.4+0.15);
+    translate([8, 0, -0.2]) cylinder($fn=32, h=10, r=2.4+0.15);
   }
 }
 
@@ -222,7 +205,7 @@ module carrier_32t() {
   difference() {
     union() {
       difference() {
-        translate([0, 0, 2]) gear_teeth(mm_per_tooth=3.06, number_of_teeth=32, thickness=4, clearance=-0.1);
+        translate([0, 0, 2]) gear_teeth(mm_per_tooth=3.06, number_of_teeth=32, thickness=4, pressure_angle=20);
         cylinder($fn=100, h=8, r=root-0.5);
       }
       difference() {
@@ -254,79 +237,34 @@ module carrier_32t() {
 }
 
 // Most compact planetary ring gear: 1 unit thick, 32 teeth outside, 24 teeth inside
-// + 3 notches at each side to lower friction
 module ring_gear_1u_32t() {
   difference() {
-    union() {
-      translate([0, 0, 2]) gear_teeth(mm_per_tooth=3.06, number_of_teeth=32, thickness=4, clearance=-0.1);
-      translate([0, 0, 0.8]) cylinder($fn=32*2, h=6.4, r=3.06*(32/2-1)/3.1415926);
-      // top knobs
-      translate([-12.8, 0, 6]) difference() {
-        sphere($fn=30, r=2, center=true);
-        translate([0, 0, -0.9]) cube(size=[6, 6, 4], center=true);
-      }
-      rotate([0, 0, 120]) translate([-12.8, 0, 6]) difference() {
-        sphere($fn=30, r=2, center=true);
-        translate([0, 0, -0.9]) cube(size=[6, 6, 4], center=true);
-      }
-      rotate([0, 0, 240]) translate([-12.8, 0, 6]) difference() {
-        sphere($fn=30, r=2, center=true);
-        translate([0, 0, -0.9]) cube(size=[6, 6, 4], center=true);
-      }
-      // bottom knobs
-      translate([-12.8, 0, 2]) difference() {
-        sphere($fn=30, r=2, center=true);
-        translate([0, 0, 0.9]) cube(size=[6, 6, 4], center=true);
-      }
-      rotate([0, 0, 120]) translate([-12.8, 0, 2]) difference() {
-        sphere($fn=30, r=2, center=true);
-        translate([0, 0, 0.9]) cube(size=[6, 6, 4], center=true);
-      }
-      rotate([0, 0, 240]) translate([-12.8, 0, 2]) difference() {
-        sphere($fn=30, r=2, center=true);
-        translate([0, 0, 0.9]) cube(size=[6, 6, 4], center=true);
-      }
-    }
-    translate([0, 0, 1.8]) gear_teeth(mm_per_tooth=3.1415926, number_of_teeth=24, thickness=4.4, clearance=-0.1);
-    translate([0, 0, -0.1]) cylinder($fn=32*2, h=8.2, r=(24/2-1));
+    gear(mm_per_tooth=3.06, number_of_teeth=32, thickness=7.8, pressure_angle=20);
+    translate([0, 0, 1.7]) gear(mm_per_tooth=3.28, number_of_teeth=24, thickness=4.4, pressure_angle=20);
+    translate([0, 0, -0.1]) cylinder($fn=32*2, h=8.2, r=3.28*(24/2-1)/3.1415926);
   }
 }
 
-// 2U 32T ring gear, with mounting holes
+// Solid easy-to-print 2U 32T ring gear, with mounting holes
 module ring_gear_2u_32t() {
   fn = 32*2;
   difference() {
     union() {
-      translate([0, 0, 10]) gear_teeth(mm_per_tooth=3.06, number_of_teeth=32, thickness=4, clearance=-0.1);
-      translate([0, 0, 2]) cylinder($fn=fn, h=14, r=3.06*(32/2-1)/3.1415926);
+      gear_teeth(mm_per_tooth=3.1, number_of_teeth=32, thickness=6.4, pressure_angle=20);
+      cylinder($fn=fn, h=13.2, r=3.1*(32/2-1)/3.1415926);
     }
-    difference() {
-      cylinder($fn=fn, h=8.8, r=3.06*(32/2+1)/3.1415926+1);
-      translate([0, 0, -0.1]) cylinder($fn=fn, h=9, r=24/2+2.1);
+    translate([0, 0, 6.4]) difference() {
+      // inner 24-teeth gear radius should be 26.4mm, but we also make it slightly bigger
+      gear(mm_per_tooth=3.28, number_of_teeth=24, thickness=8.8+0.1, pressure_angle=20);
+      // printed holes are generally smaller than model ones by 0.5-0.6mm... => +0.3 radius :-(
+      cylinder($fn=fn, h=0.8, r=2.4+1+0.3);
     }
-    translate([0, 0, -0.1]) difference() {
-      gear(mm_per_tooth=3.1415926, number_of_teeth=24, thickness=8.8+0.1, clearance=-0.1);
-      translate([0, 0, 8-0.1]) cylinder($fn=fn, h=0.8+0.2, r=3.5);
-    }
-    translate([0, 0, 9.8]) difference() {
-      cylinder($fn=fn, h=8, r=(3.06*(32/2-1)/3.1415926-1));
-      translate([-0.5, -20, -0.1]) cube(size=[1, 40, 10]);
-      translate([-20, -0.5, -0.1]) cube(size=[40, 1, 10]);
-      translate([0, 0, -0.1]) cylinder($fn=fn, h=10, r=3.5);
-      translate([0, -8, -0.1]) cylinder($fn=fn, h=10, r=3.5);
-      translate([0, 8, -0.1]) cylinder($fn=fn, h=10, r=3.5);
-      translate([-8, 0, -0.1]) cylinder($fn=fn, h=10, r=3.5);
-      translate([8, 0, -0.1]) cylinder($fn=fn, h=10, r=3.5);
-    }
-    translate([0, 0, 15.2]) difference() {
-      cylinder($fn=fn, h=1, r=(3.06*(32/2+1)/3.1415926+1));
-      translate([0, 0, -0.1]) cylinder($fn=fn, h=10, r=3.5);
-    }
-    translate([0, 0, -0.1]) cylinder($fn=fn, h=20, r=2.5);
-    translate([0, -8, -0.1]) cylinder($fn=fn, h=20, r=2.5);
-    translate([0, 8, -0.1]) cylinder($fn=fn, h=20, r=2.5);
-    translate([-8, 0, -0.1]) cylinder($fn=fn, h=20, r=2.5);
-    translate([8, 0, -0.1]) cylinder($fn=fn, h=20, r=2.5);
+    // same for other holes
+    translate([0, 0, -0.1]) cylinder($fn=fn, h=20, r=2.4+0.3);
+    translate([0, -8, -0.1]) cylinder($fn=fn, h=20, r=2.4+0.3);
+    translate([0, 8, -0.1]) cylinder($fn=fn, h=20, r=2.4+0.3);
+    translate([-8, 0, -0.1]) cylinder($fn=fn, h=20, r=2.4+0.3);
+    translate([8, 0, -0.1]) cylinder($fn=fn, h=20, r=2.4+0.3);
   }
 }
 
@@ -341,12 +279,50 @@ module satellites_32t() {
 
 //-------------
 
+// An attempt to make something like standard 20t bevel gear...
+module bevel_20t() {
+  difference() {
+    union() {
+      translate([0, 0, 1.5])
+        linear_extrude(slices=5, height=2.5, scale=(20/2+1-2.5*tan(45))/(20/2+1), twist=0)
+        gear_concat_flat(mm_per_tooth=3.53, number_of_teeth=20, backlash=2, clearance=0.8, trim_factor=0.7);
+      cylinder($fn=48, h=1.5, r=3.53*(20/2-1)/3.1415926);
+      cylinder($fn=48, h=4, r=3.53*(20/2-1)/3.1415926*(20/2+1-2.5*tan(45))/(20/2+1));
+    }
+    translate([0, 0, -0.1])
+    difference() {
+      cylinder($fn=48, h=8, r=100);
+      translate([0, 0, -0.1]) cylinder($fn=48, h=8.2, r=3.53*(20/2-1)/3.1415926);
+    }
+    axle(0, 0, -0.2, 10);
+  }
+}
+
+// An attempt to make something like standard 12t bevel gear...
+module bevel_12t() {
+  difference() {
+    union() {
+      translate([0, 0, 1.5])
+        linear_extrude(slices=5, height=2.5, scale=(12/2+1-2.5*tan(45))/(12/2+1), twist=0)
+        gear_concat_flat(mm_per_tooth=3.76, number_of_teeth=12, backlash=1, clearance=0.4, trim_factor=0.75);
+      cylinder($fn=48, h=1.5, r=3.76*(12/2-1)/3.1415926);
+      cylinder($fn=48, h=4, r=3.76*(12/2-1)/3.1415926*(12/2+1-2.5*tan(45))/(12/2+1));
+    }
+    translate([0, 0, -0.1])
+    difference() {
+      cylinder($fn=48, h=8, r=10);
+      translate([0, 0, -0.1]) cylinder($fn=48, h=8.2, r=3.76*(12/2-1)/3.1415926);
+    }
+    axle(0, 0, -0.2, 10);
+  }
+}
+
 // Standard 8-teeth gear
 module std_gear8() {
   difference() {
     union() {
       cylinder($fn=50, h=8, r=3.05*(8/2-1)/3.1415926);
-      translate([0, 0, 2.1]) gear(mm_per_tooth=3.05, number_of_teeth=8, thickness=3.8, clearance=-0.1);
+      translate([0, 0, 2.1]) gear(mm_per_tooth=3.05, number_of_teeth=8, thickness=3.8, pressure_angle=20);
     }
     axle(0, 0, -1, 10);
 }}
@@ -358,7 +334,7 @@ module planetary_ring_gear(plane_height = 1) {
     difference() {
       union() {
         cylinder($fn=80, 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, 2]) gear(mm_per_tooth=3.1, number_of_teeth=40, thickness=4, pressure_angle=20);
         translate([0, 0, 5]) cylinder($fn=80, h=2.2, r=(3.1*(40/2-1)/3.1415926));
         cylinder($fn=50, h=8, r=3.5);
       }
@@ -447,7 +423,7 @@ module offsetGearSparse(number_of_teeth, gear_height=3.9, jaggy=1) {
 module offsetGear(number_of_teeth, gear_height=3.9, jaggy=1) {
   difference() {
     union() {
-      gear(number_of_teeth=number_of_teeth, mm_per_tooth=3.05, thickness=gear_height, clearance=-0.1);
+      gear(number_of_teeth=number_of_teeth, mm_per_tooth=3.05, thickness=gear_height, pressure_angle=20);
       translate([0, 0, gear_height]) cylinder($fs=0.5, h=8-gear_height, r=3.5);
     }
     // axle hole
@@ -491,8 +467,8 @@ module offsetClutchGear(number_of_teeth, gear_height=3.8) {
 
 // Axle
 module axle(x, y, z, height) {
-  axle_gap = 1.85;
-  hole_radius = 2.5;
+  axle_gap = 1.95;
+  hole_radius = 2.55;
   union() {
     translate([x - hole_radius, y - axle_gap/2, z])
       roundedRect([hole_radius * 2, axle_gap, height], .2);
@@ -503,15 +479,22 @@ module axle(x, y, z, height) {
 
 // Axle hole (for difference()) with fixing slit
 module axleCut(x, y, z, height) {
-  axle_gap = 1.85;
-  axle_gap_cut = 1.7;
-  hole_radius = 2.5;
+  axle_gap = 1.95;
+  axle_gap_cut = 1.8;
+  hole_radius = 2.55;
   union() {
     translate([x - hole_radius, y - axle_gap/2, z])
       roundedRect([hole_radius * 2, axle_gap, height], .2);
     translate([x - axle_gap_cut/2, y - hole_radius, z])
       roundedRect([axle_gap_cut, hole_radius * 2, height], .2);
     translate([x-0.25, y-5, z]) cube(size=[0.5, 10, height]);	
+    translate([x, y, z]) difference() {
+      cylinder($fn=32, r=4, h=height);
+      translate([0, 0, -0.1]) cylinder($fn=32, r=3.6, h=height+0.2);
+      translate([-2, -5, -0.1]) cube(size=[4, 10, height+0.2]);
+/*      translate([0, -2*sqrt(2), height/2-0.1]) rotate([0, 0, 45]) cube(size=[4, 4, height+0.2], center=true);
+      translate([0, 2*sqrt(2), height/2-0.1]) rotate([0, 0, 45]) cube(size=[4, 4, height+0.2], center=true);*/
+    }
   }
 }
 
@@ -521,7 +504,7 @@ module clutchGear(number_of_teeth) {
   union() {
     difference() {
       union() {
-        gear(thickness=3.7, mm_per_tooth=3.05, number_of_teeth=number_of_teeth, clearance = -0.1);
+        gear(thickness=3.7, mm_per_tooth=3.05, number_of_teeth=number_of_teeth, pressure_angle=20);
         translate([0, 0, 1]) cylinder($fn=number_of_teeth*2, h=5.8-1, r=6.8);
         translate([0, 0, -2]) cylinder($fn=number_of_teeth*2, h=2+1, r=3.7);
       }
@@ -580,7 +563,7 @@ module myGearParamed(num_teeth, holes_row, holes_col, plus_row, plus_col)
   hole_radius = 2.5;
 
   difference() {
-    gear(thickness=gearHeight, number_of_teeth=num_teeth, mm_per_tooth=3.1415926);
+    gear(thickness=gearHeight, number_of_teeth=num_teeth, mm_per_tooth=3.06, pressure_angle=20);
 
     // We do two rectangular grids of holes, rotate 90 degrees and do them
     // again.
@@ -747,7 +730,6 @@ module gear_teeth(
   }
 };
 
-
 // Same gear, but using recursion and experimental OpenSCAD vector
 // concat() function which must be enabled at compile time with CONFIG+=experimental
 // Clean and slightly faster
@@ -774,6 +756,43 @@ module gear_concat(
     );
 };
 
+// Same in 2D (non-extruded)
+module gear_concat_flat(
+	mm_per_tooth    = 3,    //this is the "circular pitch", the circumference of the pitch circle divided by the number of teeth
+	number_of_teeth = 11,   //total number of teeth around the entire perimeter
+	pressure_angle  = 28,   //Controls how straight or bulged the tooth sides are. In degrees.
+	clearance       = 0.0,  //gap between top of a tooth on one gear and bottom of valley on a meshing gear (in millimeters)
+	backlash        = 0.0,  //gap between two meshing teeth, in the direction along the circumference of the pitch circle
+  trim_factor      = 1
+) {
+  assign(pi = 3.1415926)
+  assign(p  = mm_per_tooth * number_of_teeth / pi / 2)  //radius of pitch circle
+  assign(c  = p + mm_per_tooth / pi - clearance)        //radius of outer circle
+  assign(b  = p*cos(pressure_angle))                    //radius of base circle
+  assign(r  = p-(c-p)-clearance)                        //radius of root circle
+  assign(t  = mm_per_tooth/2-backlash/2)                //tooth thickness at pitch circle
+  assign(k  = -iang(b, p) - t/2/p/pi*180)               //angle to where involute meets base circle on each side of tooth
+    polygon(
+      points = gear_points_trimmed(r, b, c, k, number_of_teeth, number_of_teeth, trim_factor),
+      paths = [ range(15*(number_of_teeth)) ]
+    );
+};
+function gear_points_trimmed(r, b, c, k, number_of_teeth, i, f) =
+  (i <= 0 ? [] : concat(
+    gear_points_trimmed(r, b, c, k, number_of_teeth, i-1, f),
+    tooth_base_points_trimmed(r, b, c, k, number_of_teeth, i, f)
+  ));
+function tooth_base_points_trimmed(r, b, c, k, number_of_teeth, i, f) =
+  (r < b ? concat(
+    [ polar(r*f, i*360/number_of_teeth + k) ],
+    tooth_points(r, b, c, k, number_of_teeth, i),
+    [ polar(r*f, i*360/number_of_teeth - k),
+      polar(r*f, i*360/number_of_teeth + 180/number_of_teeth) ]
+  ) : concat(
+    tooth_points(r, b, c, k, number_of_teeth, i),
+    [ polar(r*f, i*360/number_of_teeth + 180/number_of_teeth) ]
+  ));
+
 function gear_points(r, b, c, k, number_of_teeth, i) =
   (i <= 0 ? [] : concat(
     gear_points(r, b, c, k, number_of_teeth, i-1),
@@ -814,7 +833,6 @@ function q7r(f,r,b,r2,t,s,rot) = q6r(b,s,t,(1-f)*max(b,r)+f*r2,rot);
 function q6r(b,s,t,d,rot)      = polar(d,rot+s*(iang(b,d)+t));
 
 
-
 // Original gear() module
 // Teeth shape is good, but the body is composed from individual sectors;
 // this sometimes results in bad "degenerate" faces due to floating point issues.