diff --git a/src/constants.rs b/src/constants.rs
index 553d9eb..e22509b 100644
--- a/src/constants.rs
+++ b/src/constants.rs
@@ -1,8 +1,13 @@
+/// Constants
+/// the native unit is mm
+
 const IN2MM: f32 = 25.4;
 pub const CHORD: f32 = 11.2 * IN2MM;
 pub const WINGSPAN: f32 = 45.0 * IN2MM;
 pub const LENGTH: f32 = 0.0;
-pub const STRUTS: usize = 10;
-pub const STRUT_WIDTH: f32 = 2.4;
-pub const SPAR_SIDE_WIDTH: f32 = 0.75;
+/// strut count in the main wing
+pub const STRUTS: usize = 6;
+pub const CARDBOARD_WIDTH: f32 = 2.4;
+/// length of each side of the triangular spar
+pub const SPAR_SIDE_WIDTH: f32 = 0.75 * IN2MM;
 pub const FUSELAGE_GAP: f32 = 10.0 * IN2MM;
diff --git a/src/main.rs b/src/main.rs
index 563e00f..745677a 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -7,6 +7,8 @@ mod selig;
 
 fn main() {
     let mut scad_file = ScadFile::new();
+    let mut parts: Vec<ScadObject> = Vec::new();
+
     scad_file.set_detail(50);
 
     // cambered airfoil, used in the wing
@@ -17,25 +19,42 @@ fn main() {
 
     let mut wing = scad!(Translate(vec3(0.0,0.0,0.0)));
 
+    // struts
     for strut_idx in 0..STRUTS + 2 {
         let port: bool = strut_idx % 2 == 1;
         let out: usize = strut_idx/2;
 
-        let mut spacing = WINGSPAN/2.0 * out as f32 + FUSELAGE_GAP / 2.0;
+        let mut spacing = WINGSPAN/STRUTS as f32 * out as f32 + FUSELAGE_GAP / 2.0;
 
         println!("{port} {out} {spacing}");
 
+        let falloff = 0.95f32.powf(spacing / 40.0);
+
         if port { spacing = -spacing };
 
         let mut transform = scad!(Translate(vec3(0.0, spacing ,0.0)));
 
-        transform.add_child(strut(&e393, CHORD, STRUT_WIDTH));
+        let strut = strut(&e393, CHORD * falloff, CARDBOARD_WIDTH);
+        parts.push(strut.clone());
+        transform.add_child(strut);
         wing.add_child(transform);
     }
 
-    scad_file.add_object(wing.clone());
+    // spars
+    scad_file.add_object(spar(WINGSPAN));
 
-    scad_file.write_to_file(String::from("out.scad"));
+    let cardboard = vec3(0.38, 0.26, 0.26);
+    scad_file.add_object(scad!(Color(cardboard); wing));
+
+    scad_file.write_to_file(String::from("build/assembly.scad"));
+
+    for (idx, part) in parts.into_iter().enumerate() {
+        let mut  file = ScadFile::new();
+        file.set_detail(50);
+        file.add_object(part);
+        file.write_to_file(format!("build/part{idx}.scad"));
+
+    }
 }
 
 /// returns a extruded airfoil with the given dimensions
@@ -55,3 +74,17 @@ fn strut(airfoil: &Airfoil, chord: f32, width: f32) -> ScadObject {
     let rotated = scad!(Rotate(90.0, vec3(1.0, 0.0, 0.0)); strut);
     rotated
 }
+
+fn spar(length: f32) -> ScadObject {
+    let mut spar = scad!(Union);
+
+    for i in 0..3 {
+        let panel = scad!(Cube(vec3(SPAR_SIDE_WIDTH, length, CARDBOARD_WIDTH)));
+        let rot = 120.0  * i as f32;
+        spar.add_child(scad!(
+            Rotate(rot, vec3(0.0, 1.0, 0.0)); panel
+        ));
+    }
+
+    spar
+}