diff --git a/src/main.rs b/src/main.rs
index fd0df79..963a2a0 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,6 +1,7 @@
 use std::{f32::consts::PI, time::Duration};
 
 use flo_draw::{
+	DrawEvent, Key,
 	canvas::{Color::Rgba, GraphicsContext},
 	create_drawing_window_with_events, with_2d_graphics,
 };
@@ -93,16 +94,23 @@ fn main() {
 		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 + ADDENDUM; n_points];
-		let show_crown_gear = false;
-		let show_crown_cutter = true;
-		let show_rack_gear = false;
-		let show_rack_cutter = true;
+		let mut bevel_shape = vec![r_pitch + 3.0 * ADDENDUM; n_points];
+		let mut show_crown_gear = false;
+		let mut show_crown_cutter = true;
+		let mut show_rack_gear = false;
+		let mut show_rack_cutter = true;
 		'main: loop {
 			while let Poll::Ready(event) =
 				events.poll_next_unpin(&mut Context::from_waker(Waker::noop()))
 			{
-				let Some(_event) = event else { break 'main };
+				let Some(event) = event else { break 'main };
+				match event {
+					DrawEvent::KeyDown(_, Some(Key::KeyTab)) => {
+						(show_crown_gear, show_crown_cutter) = (show_crown_cutter, show_crown_gear);
+						(show_rack_gear, show_rack_cutter) = (show_rack_cutter, show_rack_gear);
+					}
+					_ => {}
+				}
 			}
 			canvas.draw(|gc| {
 				gc.clear_canvas(Rgba(0.1, 0.1, 0.1, 1.0));
@@ -228,7 +236,7 @@ fn main() {
 
 				if show_crown_cutter {
 					line(gc, crown_cutter);
-					gc.stroke_color(Rgba(1.0, 1.0, 0.1, 0.4));
+					gc.stroke_color(Rgba(1.0, 0.8, 0.1, 0.4));
 					gc.stroke();
 				}
 				if show_crown_gear {
@@ -243,7 +251,7 @@ fn main() {
 				}
 				if show_rack_gear {
 					line(gc, pts_rack);
-					gc.stroke_color(Rgba(0.1, 1.0, 0.1, 0.4));
+					gc.stroke_color(Rgba(0.8, 1.0, 0.1, 0.4));
 					gc.stroke();
 				}
 			});