From fcf6ba699b512ada5363679b778dd5f4055277c0 Mon Sep 17 00:00:00 2001
From: Elmom <elmo.mantynen@iki.fi>
Date: Sun, 15 Aug 2010 12:58:20 +0300
Subject: [PATCH] incorporated 2D export to involute_gears, by Amp

---
 involute_gears.scad | 46 ++++++++++++++++++++++++++++++++-------------
 1 file changed, 33 insertions(+), 13 deletions(-)

diff --git a/involute_gears.scad b/involute_gears.scad
index 1264903..c6e6bdc 100644
--- a/involute_gears.scad
+++ b/involute_gears.scad
@@ -1,7 +1,7 @@
 // Parametric Involute Bevel and Spur Gears by GregFrost
-// It is licensed under the Creative Commons - GNU GPL license.
-// © 2010 by GregFrost
-// http://www.thingiverse.com/thing:3575
+// It is licensed under the Creative Commons - GNU LGPL 2.1 license.
+// © 2010 by GregFrost, thingiverse.com/Amp
+// http://www.thingiverse.com/thing:3575 and http://www.thingiverse.com/thing:3752
 
 // Simple Test:
 //gear (circular_pitch=700,
@@ -30,6 +30,10 @@ module test_bevel_gear_pair(){
     bevel_gear_pair ();
 }
 
+module test_bevel_gear(){bevel_gear();}
+
+bevel_gear();
+
 pi=3.1415926535897932384626433832795;
 
 //==================================================
@@ -303,7 +307,8 @@ module gear (
 	circles=0,
 	backlash=0,
 	twist=0,
-	involute_facets=0)
+	involute_facets=0,
+	flat=false)
 {
 	if (circular_pitch==false && diametral_pitch==false) 
 		echo("MCAD ERROR: gear module needs either a diametral_pitch or circular_pitch");
@@ -349,13 +354,13 @@ module gear (
 			0.70*circle_orbit_curcumference/circles,
 			(rim_radius-hub_diameter/2)*0.9);
 
-	difference ()
+	difference()
 	{
 		union ()
 		{
 			difference ()
 			{
-				linear_extrude (height=rim_thickness, convexity=10, twist=twist)
+				linear_exturde_flat_option(flat=flat, height=rim_thickness, convexity=10, twist=twist)
 				gear_shape (
 					number_of_teeth,
 					pitch_radius = pitch_radius,
@@ -370,25 +375,40 @@ module gear (
 					cylinder (r=rim_radius,h=rim_thickness-gear_thickness+1);
 			}
 			if (gear_thickness > rim_thickness)
-				cylinder (r=rim_radius,h=gear_thickness);
-			if (hub_thickness > gear_thickness)
+				linear_exturde_flat_option(flat=flat, height=gear_thickness)
+				circle (r=rim_radius);
+			if (flat == false && hub_thickness > gear_thickness)
 				translate ([0,0,gear_thickness])
-				cylinder (r=hub_diameter/2,h=hub_thickness-gear_thickness);
+				linear_exturde_flat_option(flat=flat, height=hub_thickness-gear_thickness)
+				circle (r=hub_diameter/2);
 		}
 		translate ([0,0,-1])
-		cylinder (
-			r=bore_diameter/2,
-			h=2+max(rim_thickness,hub_thickness,gear_thickness));
+		linear_exturde_flat_option(flat =flat, height=2+max(rim_thickness,hub_thickness,gear_thickness))
+		circle (r=bore_diameter/2);
 		if (circles>0)
 		{
 			for(i=[0:circles-1])	
 				rotate([0,0,i*360/circles])
 				translate([circle_orbit_diameter/2,0,-1])
-				cylinder(r=circle_diameter/2,h=max(gear_thickness,rim_thickness)+3);
+				linear_exturde_flat_option(flat =flat, height=max(gear_thickness,rim_thickness)+3)
+				circle(r=circle_diameter/2);
 		}
 	}
 }
 
+module linear_exturde_flat_option(flat =false, height = 10, center = false, convexity = 2, twist = 0)
+{
+	if(flat==false)
+	{
+		linear_extrude(height = height, center = center, convexity = convexity, twist= twist) child(0);
+	}
+	else
+	{
+		child(0);
+	}
+
+}
+
 module gear_shape (
 	number_of_teeth,
 	pitch_radius,