diff --git a/src/main.rs b/src/main.rs
index 6dd4fcf..10b123e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -2,7 +2,7 @@ use std::{f32::consts::PI, time::Duration};
 
 use flo_draw::{
 	DrawEvent, Key,
-	canvas::{Color::Rgba, GraphicsContext},
+	canvas::{Color::Rgba, GraphicsContext, GraphicsPrimitives},
 	create_drawing_window_with_events, with_2d_graphics,
 };
 use glam::{FloatExt, Vec2, mat3, vec2, vec3};
@@ -80,6 +80,15 @@ fn main() {
 			mat3(vec3(1.0, 0.0, 0.0), vec3(0.0, c, s), vec3(0.0, -s, c))
 		};
 
+		let adjust_offset = |off: f32| {
+			let (s, c) = crown_angle.sin_cos();
+			let pitch = vec2(r_crown * c, r_pitch);
+			let offset = off * vec2(s, -c);
+			let pt = pitch + offset;
+			let intersect = pt * (pitch.x / pt.x);
+			r_pitch - intersect.y
+		};
+		let adjust_angle = |angle: f32| (angle.tan() * crown_angle.cos()).atan();
 		let gear_profile = Profile {
 			addemdum: ADDENDUM,
 			dedendum: DEDENDUM,
@@ -90,11 +99,21 @@ fn main() {
 			dedendum: gear_profile.addemdum,
 			pressure_angle: gear_profile.pressure_angle,
 		};
+		let gear_profile_adj = Profile {
+			addemdum: adjust_offset(gear_profile.addemdum),
+			dedendum: -adjust_offset(-gear_profile.dedendum),
+			pressure_angle: adjust_angle(gear_profile.pressure_angle),
+		};
+		let cutter_profile_adj = Profile {
+			addemdum: adjust_offset(cutter_profile.addemdum),
+			dedendum: -adjust_offset(-cutter_profile.dedendum),
+			pressure_angle: adjust_angle(cutter_profile.pressure_angle),
+		};
 
 		let n_points_per_tooth = 100;
 		let n_points = n_points_per_tooth * n_teeth_sample;
-		let mut inv_shape = vec![r_pitch + ADDENDUM; n_points];
-		let mut bevel_shape = vec![r_pitch + 3.0 * ADDENDUM; n_points];
+		let mut inv_shape = vec![r_pitch + gear_profile_adj.addemdum; n_points];
+		let mut bevel_shape = vec![r_pitch + gear_profile_adj.addemdum; n_points];
 		let mut show_crown_gear = false;
 		let mut show_crown_cutter = true;
 		let mut show_rack_gear = false;
@@ -156,7 +175,7 @@ fn main() {
 				let crown_cutter = make_crown(&cutter_profile);
 
 				let rack_y_at_x = |x, profile| rack_shape(x - rack_offset * PI, profile);
-				let inv_cutter_y_at_x = |x| rack_y_at_x(x, &cutter_profile);
+				let inv_cutter_y_at_x = |x| rack_y_at_x(x, &cutter_profile_adj);
 
 				let bevel_cutter: Vec<_> = crown_cutter
 					.iter()
@@ -213,6 +232,11 @@ fn main() {
 				gc.close_path();
 				gc.stroke_color(Rgba(0.3, 0.3, 0.3, 0.4));
 				gc.stroke();
+				gc.stroke_color(Rgba(0.3, 0.3, 0.3, 0.1));
+				gc.circle(0.0, r_pitch, r_pitch - gear_profile_adj.dedendum);
+				gc.circle(0.0, r_pitch, r_pitch);
+				gc.circle(0.0, r_pitch, r_pitch + gear_profile_adj.addemdum);
+				gc.stroke();
 
 				line(
 					gc,
@@ -228,7 +252,7 @@ fn main() {
 					for k in 0..n_points_per_tooth {
 						let x = (tooth as f32 + k as f32 / n_points_per_tooth as f32 + rack_offset)
 							* PI;
-						pts_rack.push(vec2(x, rack_y_at_x(x, &gear_profile)));
+						pts_rack.push(vec2(x, rack_y_at_x(x, &gear_profile_adj)));
 						pts_cutter.push(vec2(x, inv_cutter_y_at_x(x)));
 					}
 				}