From b2fe6b83fb1b605d79eb5b9978414fd1186f91f5 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Tue, 27 May 2014 22:00:26 +0100
Subject: [PATCH] brompton-computer-guard: wip, have arch

---
 brompton-computer-guard.scad | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/brompton-computer-guard.scad b/brompton-computer-guard.scad
index 114c5e3..1744ac7 100644
--- a/brompton-computer-guard.scad
+++ b/brompton-computer-guard.scad
@@ -1,2 +1,38 @@
 // -*- C -*-
 
+arch_height = 24;
+arch_width = 75;
+end_width = 25;
+
+arch_thick = 5;
+
+// computed
+
+arch_alpha = atan(arch_height / (arch_width/2));
+arch_beta = 2*arch_alpha;
+echo(arch_alpha,arch_beta);
+arch_in_rad = arch_width/2 / sin(arch_beta);
+arch_to_chord = arch_in_rad * cos(arch_beta);
+
+//arch_to_chord = (arch_width/2)*(arch_width/2)/arch_height;
+//arch_in_rad = arch_to_chord + arch_height;
+//arch_in_rad2 = sqrt(arch_to_chord*arch_to_chord +
+//		    (arch_width/2)*(arch_width/2));
+
+//echo(arch_in_rad, arch_in_rad2);
+
+module ArchProfile(){
+  intersection(){
+    translate([-200,0])
+      square([400,200]);
+    translate([0,-arch_to_chord]){
+      difference(){
+	circle(arch_in_rad + arch_thick, $fa=0.1);
+	circle(arch_in_rad, $fa=0.1);
+      }
+    }
+  }
+  %square([arch_width/2,arch_height]);
+}
+
+ArchProfile();
-- 
2.30.2