initial negative spar

openscad does not support 3d shape interpolation aside from hulls. oops.

src/constants.rs

@@ -2,12 +2,12 @@
 /// the native unit is mm
 
 const IN2MM: f32 = 25.4;
-pub const CHORD: f32 = 5.0 * IN2MM;
+pub const CHORD: f32 = 7.0 * IN2MM;
 pub const WING_TAPER: f32 = 0.6;
 pub const WINGSPAN: f32 = 45.0 * IN2MM;
 pub const LENGTH: f32 = 30.0*IN2MM;
 /// strut count in the main wing
-pub const STRUTS: usize = 20;
+pub const STRUTS: usize = 12;
 pub const CARDBOARD_WIDTH: f32 = 2.4;
 /// length of each side of the triangular spar
 pub const SPAR_SIDE_WIDTH: f32 = 0.75 * IN2MM;
@@ -19,6 +19,8 @@ pub const RUDDER_CHORD: f32 = 3.0 *IN2MM;
 pub const RUDDER_TAPER: f32 = 0.7;
 pub const RUDDER_STRUTS: usize = 3;
 pub const ELEVATOR_HEIGHT: f32 = 8.0 *IN2MM;
-pub const ELEVATOR_CHORD: f32 = 3.0 *IN2MM;
+pub const ELEVATOR_CHORD: f32 = 5.0 *IN2MM;
 pub const ELEVATOR_TAPER: f32 = 0.7;
-pub const ELEVATOR_STRUTS: usize = 3;
+pub const ELEVATOR_STRUTS: usize = 4;
+pub const STOCK_HEIGHT: f32 = 25.0 *IN2MM;
+pub const STOCK_WIDTH: f32 = 36.0 *IN2MM;

src/main.rs

@@ -37,13 +37,16 @@ fn main() {
     // struts
     for port in [true,false] {
         let mut wing = wing(&wing_airfoil, STRUTS/2, WINGSPAN/2.0, CHORD, CHORD * WING_TAPER, SparType::Top);
+        let top_spar = topwing_spar(&wing_airfoil, STRUTS/2, WINGSPAN/2.0, CHORD, CHORD * WING_TAPER);
         wing = scad!(Translate(vec3(0.0, FUSELAGE_GAP,0.0)); wing);
+        wing.add_child(top_spar);
         if port {
             wing = scad!(Mirror(vec3(0.0, 1.0, 0.0)); wing);
         }
         wing_transform.add_child(wing);
     }
 
+
     // spars
 
     // "fuselage"
@@ -116,6 +119,10 @@ fn strut(airfoil: &Airfoil, chord: f32, width: f32, spar: &SparType) -> ScadObje
         }
     };
 
+    extrude_strut(shape, strut_hole, width, chord)
+}
+
+fn extrude_strut(shape: ScadObject, strut_hole: ScadObject, width: f32, chord: f32) -> ScadObject {
     let mut strut_shape = scad!(Difference);
     strut_shape.add_child(shape);
     strut_shape.add_child(strut_hole);
@@ -210,6 +217,52 @@ fn wing(aerofoil: &Airfoil, struts: usize, length: f32, chord: f32, taper: f32,
     wing
 }
 
+fn topwing_spar(aerofoil: &Airfoil, struts: usize, length: f32, chord: f32, taper: f32) -> ScadObject {
+    let mut wing = scad!(Translate(vec3(0.0,0.0,0.0)));
+
+    let mut last_segment : Option<ScadObject> = None;
+    let mut pre_vis = scad!(Union);
+
+    // struts
+    for strut_idx in 0..struts + 1 {
+
+        let gap = length/struts as f32;
+
+        let chord = lerp(chord, taper, strut_idx as f32 / struts as f32);
+
+        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);
+
+        let mut transform = scad!(Translate(vec3(0.0, spacing ,0.0)));
+        transform.add_child(extruded);
+
+
+        // in betweens
+        if let Some(last) = last_segment {
+            let mut hull = scad!(Hull);
+            hull.add_child(last);
+            hull.add_child(shape.clone());
+
+            let unit: Vector3<f32> = Vector3::new(1.0, 1.0, 1.0);
+            hull = scad!(Scale(unit * chord); hull);
+
+            hull = scad!(Rotate(90.0, vec3(1.0, 0.0, 0.0)); hull);
+
+            transform.add_child(hull);
+        }
+
+        pre_vis.add_child(transform);
+
+        last_segment = Some(shape);
+    }
+
+    wing.add_child(pre_vis);
+
+    wing
+}
+
 pub fn points_in_range(input: &Vec<Point>, range: Range<f32>) -> Vec<Point> {
     let mut last_point: Option<Point> = None;
     let mut distance: f32 = 0.0;