diff --git a/src/main.rs b/src/main.rs
index 10b123e..fa42271 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -195,13 +195,14 @@ fn main() {
 				};
 
 				for (k, r) in inv_shape.iter_mut().enumerate() {
-					loop {
-						let xy = kr_to_xy(k, *r);
+					let mut test_r = *r;
+					while test_r > r_pitch - gear_profile_adj.dedendum {
+						let xy = kr_to_xy(k, test_r);
 						let cut_y = inv_cutter_y_at_x(xy.x);
-						if cut_y < xy.y {
-							break;
+						if cut_y > xy.y {
+							*r = test_r;
 						}
-						*r -= 0.01;
+						test_r -= 0.01;
 					}
 				}