diff --git a/src/shapes/ISO_enter.scad b/src/shapes/ISO_enter.scad
index 8c5730f..480051f 100644
--- a/src/shapes/ISO_enter.scad
+++ b/src/shapes/ISO_enter.scad
@@ -2,6 +2,10 @@
 // NOT 3D
 function unit_length(length) = unit * (length - 1) + 18.16;
 
+width_ratio = unit_length(1.25) / unit_length(1.5);
+height_ratio = unit_length(1) / unit_length(2);
+
+
 module ISO_enter_shape(size, delta, progress){
   width = size[0];
   height = size[1];
@@ -13,43 +17,42 @@ module ISO_enter_shape(size, delta, progress){
   // and wants to pass just width and height, we make these ratios to know where
   // to put the elbow joint
 
-  width_ratio = unit_length(1.25) / unit_length(1.5);
-  height_ratio = unit_length(1) / unit_length(2);
+  delta = delta / 2;
 
   pointArray = [
-      [                   0,                     0], // top right
-      [                   0,               -height], // bottom right
-      [-width * width_ratio,               -height], // bottom left
-      [-width * width_ratio,-height * height_ratio], // inner middle point
-      [              -width,-height * height_ratio], // outer middle point
-      [              -width,                     0]  // top left
+      [                   0-delta.x,                     0-delta.y], // top right
+      [                   0-delta.x,               -height+delta.y], // bottom right
+      [-width * width_ratio+delta.x,               -height+delta.y], // bottom left
+      [-width * width_ratio + delta.x,-height * height_ratio+delta.y], // inner middle point
+      [              -width + delta.x,-height * height_ratio + delta.y], // outer middle point
+      [              -width + delta.x,                     0-delta.y]  // top left
   ];
 
   minkowski(){
-    circle(r=corner_size);
+    circle(r=$corner_radius);
     // gives us rounded inner corner
-    offset(r=-corner_size*2) {
+    offset(r=-$corner_radius*2) {
       translate([(width * width_ratio)/2, height/2]) polygon(points=pointArray);
     }
   }
 }
 
-function iso_enter_vertices(width, height, width_ratio, height_ratio, wd, hd) = [
-  [                   0-wd,                     0-hd], // top right
-  [                   0-wd,               -height+hd], // bottom right
-  [-width * width_ratio+wd,               -height+hd], // bottom left
-  [-width * width_ratio+wd,-height * height_ratio+hd], // inner middle point
-  [              -width+wd,-height * height_ratio+hd], // outer middle point
-  [              -width+wd,                     0-hd]  // top left
+function iso_enter_vertices(size, delta, progress, thickness_difference) = [
+  [                       0-delta.x/2 * progress - thickness_difference/2,                      0 - delta.y / 2 * progress - thickness_difference/2], // top right
+  [                       0-delta.x/2 * progress - thickness_difference/2,               -size[1] + delta.y / 2 * progress + thickness_difference/2], // bottom right
+  [-size[0] * width_ratio + delta.x/2 * progress + thickness_difference/2,               -size[1] + delta.y / 2 * progress + thickness_difference/2], // bottom left
+  [-size[0] * width_ratio + delta.x/2 * progress + thickness_difference/2,-size[1] * height_ratio + delta.y / 2 * progress + thickness_difference/2], // inner middle point
+  [              -size[0] + delta.x/2 * progress + thickness_difference/2,-size[1] * height_ratio + delta.y / 2 * progress + thickness_difference/2], // outer middle point
+  [              -size[0] + delta.x/2 * progress + thickness_difference/2,                      0 - delta.y / 2 * progress - thickness_difference/2]  // top left
 ] + [
-  [(width * width_ratio)/2, height/2 ],
-  [(width * width_ratio)/2, height/2 ],
-  [(width * width_ratio)/2, height/2 ],
-  [(width * width_ratio)/2, height/2 ],
-  [(width * width_ratio)/2, height/2 ],
-  [(width * width_ratio)/2, height/2 ]
+  [(size[0] * width_ratio)/2, size[1]/2 ],
+  [(size[0] * width_ratio)/2, size[1]/2 ],
+  [(size[0] * width_ratio)/2, size[1]/2 ],
+  [(size[0] * width_ratio)/2, size[1]/2 ],
+  [(size[0] * width_ratio)/2, size[1]/2 ],
+  [(size[0] * width_ratio)/2, size[1]/2 ]
 ];
 
 // no rounding on the corners at all
 function skin_iso_enter_shape(size, delta, progress, thickness_difference) =
-  iso_enter_vertices(size.x, size.y, unit_length(1.25) / unit_length(1.5), unit_length(1) / unit_length(2), thickness_difference/2 + delta.x * progress/2, thickness_difference/2 + delta.y * progress/2);
+  iso_enter_vertices(size, delta, progress, thickness_difference);