diff --git a/src/constants.rs b/src/constants.rs
index 6a132fc..66283d1 100644
--- a/src/constants.rs
+++ b/src/constants.rs
@@ -44,6 +44,7 @@ pub const ELEVATOR: WingConfig = WingConfig {
     taper: ELEVATOR_TAPER,
     struts: ELEVATOR_STRUTS,
 };
+pub const TOPSPAR_RANGE: Range<f32> = 0.1..0.6;
 pub const MIDSPAR_RANGE: Range<f32> = 0.1..0.4;
 pub const STOCK_HEIGHT: f32 = 25.0 * IN2MM;
 pub const STOCK_WIDTH: f32 = 37.0 * IN2MM;
diff --git a/src/main.rs b/src/main.rs
index 0f53897..9d2e3c1 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -214,7 +214,7 @@ fn strut(airfoil: &SeligFile, chord: f32, width: f32, spar: &SparType) -> Constr
 
     let strut_hole = {
         match spar {
-            SparType::Top => topspar_negative(airfoil, chord, 0.1..0.6),
+            SparType::Top => topspar_negative(airfoil, chord, TOPSPAR_RANGE),
             SparType::Center => {
                 scad!(Translate2d(vec2(MIDSPAR_RANGE.start, 0.0)); 
                 centered_square(vec2(MIDSPAR_RANGE.end -  MIDSPAR_RANGE.start, CARDBOARD_WIDTH/ chord), (false,true))