digispark-with-cable: wip progress

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/digispark-with-cable.scad b/digispark-with-cable.scad
index 069c04bf1ae8ca2820a40a53e8f52eddece2e2cc..e055eacc5f0cd9ea872604fb5a1104444d3989d8 100644 (file)
--- a/digispark-with-cable.scad
+++ b/digispark-with-cable.scad
@@ -39,6 +39,8 @@ strain_w = 2.0 + 0.5;
 strain_t = 1.0 + 0.5;
 strain_pitch_across = 5;
 strain_pitch_along = 10;
+strain_groove_d = 2;
+strain_groove_w = 3;
 
 // calculated
 
@@ -93,12 +95,28 @@ module TopMainWallsPlan() {
 }
 
 module Top(){ ////toplevel
-  linextr(0, usb_wall_h)
-    TopSmallWallsPlan();
-  linextr(usb_wall_h - usb_ceil_th, usb_wall_h)
-    TopCeilPlan();
-  linextr(-board_th, usb_wall_h)
-    TopMainWallsPlan();
+  difference(){
+    union(){
+      linextr(0, usb_wall_h)
+       TopSmallWallsPlan();
+      linextr(usb_wall_h - usb_ceil_th, usb_wall_h)
+       TopCeilPlan();
+      linextr(-board_th, usb_wall_h)
+       TopMainWallsPlan();
+    }
+
+    for (y_c = [strain_0_y_c, strain_1_y_c]) {
+      for (x_c = [-1,+1] * strain_pitch_across/2) {
+       translate([x_c, y_c, 0])
+         linextr(-20, 20)
+         square([ strain_t, strain_w ], center=true);
+      }
+    }
+    linextr_y_xz(total_y_min-1, main_y_min)
+      translate([0, -board_th])
+      scale([1, strain_groove_d/strain_groove_w])
+      circle(strain_groove_w/2, $fn = 8);
+  }
 }
 
 module Bottom(){ ////toplevel