diff --git a/common.scad b/common.scad
index 95e6b10..18c630f 100644
--- a/common.scad
+++ b/common.scad
@@ -12,7 +12,7 @@ Z=2;
 OFFSET=0.01; 
 
 
-/*
+/**
  * Handle for bézier point
  * 
  * @param point     - Point to manage
@@ -27,7 +27,9 @@ function handle(point,angle,strength) = [
 
 
 
-
+/**
+ * Show Debug point
+ */
 module debugPoint(point, id, color) {
     translate(point) {
         color(color) sphere(r = 1.5);
@@ -40,3 +42,84 @@ module debugPoint(point, id, color) {
         }
     }
 }
+
+/**
+ * Displays debug information for a path by visualizing its self-crossings.
+ * 
+ * @param path - The input path to analyze for self-crossings.
+ * 
+ * This module:
+ * - Splits the path at points where it intersects itself.
+ * - Renders each segment of the split path with different colors for easy identification.
+ */
+module showDebugPath(path) {
+    assert(is_path(path),"Path to show is not a path");
+    assert(is_path_simple(path),"Path is not simple");
+    rainbow(split_path_at_self_crossings(path)) 
+        stroke($item, closed=false, width=0.2);
+}
+
+
+/**
+ * Rounded Triangle
+ */
+module rounded_triangle(radius, height) {
+    triangle_points = [[0, 0], [75, 0], [0, -35]]; // Equilateral triangle with side length 100
+    rounded_shape = round_corners( triangle_points, r=radius );
+    mirror([0,0,1]) linear_extrude(height = height) polygon(rounded_shape);
+}
+
+
+/**
+ * Function to translate a path manually along X and Y
+ * 
+ * @param path  - Original path
+ * @param dx    - x translation 
+ * @param dy    - y translation 
+ */ 
+function translate_path(path, dx=0, dy=0) = [for (p = path) [p[0] + dx, p[1] + dy]];   
+
+
+/**
+ * Convert points to bezier curve
+ *
+ * @param points  - Points
+ */
+function asCurve( points ) = bezpath_curve(points,N=3,splinesteps=64);
+
+
+
+//function asCurve2( points ) = path_to_bezpath(bezier_curve(points,splinesteps=64));
+
+//path_to_bezpath
+
+/**
+ * Print path points
+ */
+module print_path_points(path) {
+    for (i = [0:len(path)-1]) {
+        echo(str("\t Point ", i, ": [", path[i][0], ", ", path[i][1], "]"));
+    }
+}
+
+/**
+ * Expand path 
+ *
+ * @param path - Original path
+ * param delta - distance to expand
+ */
+function expandPath(path,delta) = 
+        offset(
+            deduplicate(path),
+            delta=delta,
+            chamfer=false,
+            same_length=true
+       )
+    ;
+
+
+/**
+ * Inches to centimeter conversion
+ */ 
+function inches_to_cm(inches) = inches * 2.54;
+