diff --git a/math.scad b/math.scad
index 00b7ee1..c4c69ee 100644
--- a/math.scad
+++ b/math.scad
@@ -3,3 +3,5 @@ function normalize(vec) = vec / norm(vec);
 function lerp(a,b,t) = a + (b - a) * t;
 
 function scale_xy(shape, xy, allow_zero = false) = let(s = allow_zero ? xy : sign(xy == 0 ? 1 : xy) * max(abs(xy), 0.0001)) [ for (i = shape) [i.x * s, i.y * s]];
+
+function add_z(z, m) = [ for (i = m) concat(i, z) ];
diff --git a/poly_gates.scad b/poly_gates.scad
index 7c63794..7a06889 100644
--- a/poly_gates.scad
+++ b/poly_gates.scad
@@ -1,75 +1,17 @@
 $fn = 32;
 gate_height = 50;
 
+include<math.scad>;
+include<shapes.scad>;
+include<round_poly.scad>;
 
-sq_poly = let(corner = 1 / sqrt(2)) [
-  [-corner, -corner],
-  [corner, -corner],
-  [corner, corner],
-  [-corner, corner],
-];
+function throw_travel(throw) = gate_height * tan(throw);
 
-oct_poly = let(corner = 1 / sqrt(2))[
-  [-corner, -corner],
-  [0,-1],
-  [corner, -corner],
-  [1,0],
-  [corner, corner],
-  [0,1],
-  [-corner, corner],
-  [-1,0],
-];
-
-octn_poly = let(corner = 1 / sqrt(2 / 1.2))[
-  [-corner, -corner],
-  [0,-1],
-  [corner, -corner],
-  [1,0],
-  [corner, corner],
-  [0,1],
-  [-corner, corner],
-  [-1,0],
-];
-
-function scale_xy(xy, m) = [ for (i = m) [i.x * xy, i.y * xy]];
-
-function add_z(z, m) = [ for (i = m) concat(i, z) ];
-
-function throw_end(throw, base_offset) = base_offset + gate_height * tan(throw);
-
-function throw_polygons(shape, throw, base_offset = 0) = let(b_scale = base_offset < 0 ? 1 : base_offset)[ 
-  add_z(0, scale_xy(b_scale, shape)), 
-  add_z(gate_height, scale_xy(throw_end(throw, base_offset), shape))
-];
-
-function throw_points(shape, throw, base_offset = 0) = let(polys = throw_polygons(shape, throw, base_offset)) [
-  for(i = [0,len(polys) - 1]) each polys[i]
-];
-
-function throw_faces(points) = let(length = len(points), half = len(points) / 2) [
-  [for(i = [0:half - 1]) i],
-  [half, half + 1, 1, 0],
-  [for(i = [length - 1:-1:half]) i],
-  for(i = [1:half - 2]) [half + i, half + i + 1, i + 1, i],
-  [length - 1, half, 0, half - 1]
-];
-
-function lerp(a,b,t) = a + (b - a) * t;
-
-module shape_gate (shape, throw, shaft_r, sharpness = 1) {
-  corner_r = shaft_r * sharpness;
-  corner_offset = shaft_r - corner_r;
-
-  points = throw_points(shape, throw, corner_offset);
-  
-  minkowski(){
-    polyhedron(points, throw_faces(points));
-    cylinder(1, corner_r);
+module shape_gate (shape, throw, shaft_r, sharpness = 0) {
+  hull(){
+    round_poly(shape, shaft_r, sharpness);
   }
 }
 
-sharpness = $t;
-echo(sharpness);
-
-shape_gate(sq_poly, 10, 9 / 2, 1);
+shape_gate(sqr_poly, 10, 9 / 2, 1);
   
diff --git a/round_polygon.scad b/round_poly.scad
similarity index 95%
rename from round_polygon.scad
rename to round_poly.scad
index ca30564..221f3e2 100644
--- a/round_polygon.scad
+++ b/round_poly.scad
@@ -1,4 +1,4 @@
-use<math.scad>;
+include<math.scad>;
 
 module round_poly(shape, radius, size = 0, sharpness = 0){
   function grow(s, m) = [ for (i = s) i + normalize(i) * m];
diff --git a/shapes.scad b/shapes.scad
new file mode 100644
index 0000000..4bbf4ac
--- /dev/null
+++ b/shapes.scad
@@ -0,0 +1,29 @@
+sqr_poly = let(corner = 1 / sqrt(2)) [
+  [-corner, -corner],
+  [corner, -corner],
+  [corner, corner],
+  [-corner, corner],
+];
+
+oct_poly = let(corner = 1 / sqrt(2))[
+  [-corner, -corner],
+  [0,-1],
+  [corner, -corner],
+  [1,0],
+  [corner, corner],
+  [0,1],
+  [-corner, corner],
+  [-1,0],
+];
+
+octn_poly = let(corner = 1 / sqrt(2 / 1.2))[
+  [-corner, -corner],
+  [0,-1],
+  [corner, -corner],
+  [1,0],
+  [corner, corner],
+  [0,1],
+  [-corner, corner],
+  [-1,0],
+];
+