// -*- C -*-
-arch_height = 24;
+arch_height = 18;
arch_width = 75;
end_width = 25;
-arch_thick = 5;
+arch_thick = 4;
arch_breadth = 25;
-hole_dia = 3 + 0.5;
+hole_dia = 4 + 0.5;
+
+pbase_tab = 12;
+pbase_thick = 4;
// computed
arch_in_rad = arch_width/2 / sin(arch_beta);
arch_to_chord = arch_in_rad * cos(arch_beta);
+inner_pbase_thick = 8;
+echo(inner_pbase_thick);
+
+inner_pbase_rad = arch_in_rad * 2;
+
end_thick = arch_thick;
holes = [[[ 5 , 5 ], [16 , 21]], // left
- [[ 18.5, 4.5], [ 4.5, 22]]]; // right
+ [[ 18.5, 4.5], [ 4.5, 21]]]; // right
+
+module ArchCircle(rad){
+ translate([0,-arch_to_chord])
+ circle(rad, $fa=0.1);
+}
-module ArchProfile(){
+module ArchProfile(pbase){
intersection(){
translate([-200,0])
square([400,200]);
- union(){
- translate([0,-arch_to_chord]){
- difference(){
- circle(arch_in_rad + arch_thick, $fa=0.1);
- circle(arch_in_rad, $fa=0.1);
- }
+ difference(){
+ union(){
+ ArchCircle(arch_in_rad + arch_thick);
+ for (m=[0,1])
+ mirror([m,0])
+ translate([arch_width/2,0])
+ multmatrix([[1,pbase ? -0.75 : 0,0,0],
+ [0,1,0,0],
+ [0,0,1,0],
+ [0,0,0,1]])
+ square([end_width, pbase ? pbase_tab : end_thick]);
}
- for (m=[0,1])
- mirror([m,0])
- translate([arch_width/2,0])
- square([end_width, end_thick]);
}
}
}
}
}
+module MainCutout(){
+ ArchCircle(arch_in_rad);
+}
+
module Arch(){
difference(){
- rotate([0,0,180])
- linear_extrude(height=arch_breadth) ArchProfile();
+ rotate([0,0,180]){
+ linear_extrude(height=arch_breadth) {
+ difference(){
+ ArchProfile(false);
+ MainCutout();
+ }
+ }
+ difference(){
+ translate([0,0, arch_breadth - pbase_thick])
+ linear_extrude(height=pbase_thick){
+ difference(){
+ hull(){
+ ArchProfile(true);
+ ArchProfile(false);
+ }
+ intersection(){
+ MainCutout();
+ translate([0, -inner_pbase_thick
+ - (inner_pbase_rad - arch_in_rad)])
+ ArchCircle(inner_pbase_rad);
+ }
+ }
+ }
+ }
+ }
Holes();
}
}
-Arch();
+rotate([0,0,45]) translate([0,0,arch_breadth]) rotate([0,180,0]) Arch();