diff --git a/src/main.rs b/src/main.rs
index 9d2e3c1..2efda1f 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -10,8 +10,6 @@ use std::ops::Range;
 mod constants;
 mod selig;
 
-static PARTS: Mutex<Vec<ScadObject>> = Mutex::new(Vec::new());
-
 fn main() {
     let mut scad_file = ScadFile::new();
     //let mut parts: Vec<ScadObject> = Vec::new();
@@ -70,7 +68,7 @@ fn main() {
 
     scad_file.write_to_file(String::from("build/assembly.scad"));
 
-    for (idx, part) in PARTS.lock().unwrap().clone().into_iter().enumerate() {
+    for (idx, part) in parts.clone().into_iter().enumerate() {
         let mut file = ScadFile::new();
         file.set_detail(50);
         file.add_object(part);
@@ -79,7 +77,7 @@ fn main() {
 
     let mut allparts = ScadFile::new();
     allparts.set_detail(50);
-    for (idx, part) in PARTS.lock().unwrap().iter().cloned().enumerate() {
+    for (idx, part) in parts.into_iter().enumerate() {
         allparts.add_object(scad!(Translate2d(vec2(0.0, INF * idx as f32)); part));
     }
     allparts.write_to_file("build/allparts.scad".to_string());
@@ -256,7 +254,6 @@ fn extrude_strut(
     strut_hole: ScadObject,
     width: f32,
     chord: f32,
-    register: bool,
 ) -> ScadObject {
     let mut strut_shape = scad!(Difference);
     strut_shape.add_child(shape);
@@ -272,9 +269,6 @@ fn extrude_strut(
 
     let unit: Vector3<f32> = Vector3::new(1.0, 1.0, 1.0);
     let scaled = scad!(Scale(unit * chord); shape);
-    if register {
-        register_part(scaled.clone());
-    }
     let strut = scad!(LinearExtrude(extrude); scaled);
     let rotated = scad!(Rotate(90.0, vec3(1.0, 0.0, 0.0)); strut);
     rotated
@@ -303,14 +297,14 @@ fn topspar_negative(airfoil: &SeligFile, chord: f32, range: Range<f32>) -> ScadO
         }
         last = Some(current);
     }
-    register_part(mask.clone());
     mask
 }
 
+// TODO: shift to trangle design
 fn spar(length: f32, center: bool) -> ScadObject {
     let mut spar = scad!(Union);
 
-    register_part(scad!(Square(vec2(length, SPAR_SIDE_WIDTH * 3.0))));
+    //register_part(scad!(Square(vec2(length, SPAR_SIDE_WIDTH * 3.0))));
 
     for i in 0..3 {
         let mut panel = scad!(Cube(vec3(SPAR_SIDE_WIDTH, length, CARDBOARD_WIDTH)));
@@ -326,10 +320,6 @@ fn spar(length: f32, center: bool) -> ScadObject {
     spar
 }
 
-fn register_part(part: ScadObject) {
-    PARTS.lock().unwrap().push(part);
-}
-
 fn lerp(a: f32, b: f32, x: f32) -> f32 {
     a * (1.0 - x) + b * x
 }
@@ -379,7 +369,7 @@ fn topwing_spar(
         let spacing = strut_idx as f32 * gap;
 
         let shape = topspar_negative(aerofoil, chord, 0.1..0.6);
-        let extruded = extrude_strut(shape.clone(), scad!(Union), CARDBOARD_WIDTH, chord, false);
+        let extruded = extrude_strut(shape.clone(), scad!(Union), CARDBOARD_WIDTH, chord);
 
         let mut transform = scad!(Translate(vec3(0.0, spacing, 0.0)));
         transform.add_child(extruded);