// -*- C -*-
-tube_dia = 27.5 + 0.5;
+// use shell thickness 1.50
+// use fill density 40%
+
+include <funcs.scad>
+
+tube_dia = 27.5 + 1.625;
lock_w = 42.5 + 0.5;
lock_d = 28.0 + 0.5;
main_h = 45.0;
backflange_d = 12;
+lockshaft_dia = 14.35;
-lockshaft_r = [5, 5];
cliprecess_h = 16;
total_h = 45;
-back_gap = 7;
-main_th = 2.5;
+back_gap = 12.5;
+main_th = 2.75;
+tube_th = 2.125;
+
midweb_d = 3;
-clip_th = 2.5;
+clip_th = 3.5;
clip_gap = 2.5;
clip_d = 22.0;
mountscrew_dia = 4 + 0.5;
-clipbolt_dia = 5 + 0.5;
+clipbolt_dia = 5 + 0.1;
+
+backflange_th = 4.5;
+
+$fn=50;
+
+join_cr = 9;
+
+tube_rear_extra_th = 1;
// calculated
+lockshaft_r = [1, 1] * lockshaft_dia / 2;
front_th = main_th;
-tube_or = tube_dia/2 + main_th;
-back_ohw = back_gap/2 + main_th;
+tube_or = tube_dia/2 + tube_th;
+back_ohw = back_gap/2 + backflange_th;
backflange_ymin = tube_or+backflange_d;
lock_0y = tube_dia/2 + lock_d/2 + midweb_d;
+lock_0x = lock_w/2 - lock_d/2;
+lock_0 = [lock_0x,lock_0y];
lock_or = [lock_w, lock_d]/2 + [front_th,front_th];
}
}
+module JoinCircs(jr){
+ // http://mathworld.wolfram.com/Circle-CircleIntersection.html
+ R = tube_or + join_cr;
+ r = lock_or[1] + join_cr;
+ d = dist2d( [0,0], lock_0 );
+ x = (d*d - r*r + R*R) / (2*d);
+ y = sqrt( R*R - x*x );
+
+ echo(lock_0x, lock_0y, R,r, d, x,y);
+
+ for (m=[0,1]) {
+ mirror([m,0]) {
+ rotate(atan2(lock_0y, lock_0x)) {
+ translate([x,-y])
+ circle(r= jr);
+ }
+ }
+ }
+}
+
module MainPlan(){
difference(){
union(){
- circle(r = tube_or);
+ hull(){
+ for (t=[0, tube_rear_extra_th])
+ translate([0, -t])
+ circle(r = tube_or);
+ }
translate([-back_ohw,0]) mirror([0,1])
square([back_ohw*2, backflange_ymin]);
+
+ translate([0, lock_0y]){
+ oval(lock_or);
+ }
+
+ hull(){
+ JoinCircs(0.01);
+ polygon([[0,0], lock_0, [-lock_0[0], lock_0[1]]]);
+ }
}
+
circle(r = tube_dia/2);
translate([-back_gap/2,1]) mirror([0,1])
square([back_gap, backflange_ymin+2]);
- }
- translate([0, lock_0y]){
- difference(){
- union(){
- oval(lock_or);
- }
+
+ translate([0, lock_0y]){
oval([lock_w/2, lock_d/2]);
}
+
+ JoinCircs(join_cr);
}
}
clip_ogap = clip_gap + clip_th*2;
module ClipElevationPositive(){
- oval(lockshaft_or);
+ hull(){
+ oval(lockshaft_or);
+ translate([0, -lockshaft_or[1] * sqrt(2)])
+ square(center=true, 0.5);
+ }
translate([-lockshaft_or[0], 0])
square([lockshaft_or[0]*2, cliprecess_ymax]);
translate([-clip_ogap/2, 0]) mirror([0,1]) square([clip_ogap, -clip_ymin]);
}
ThroughHole( clipbolt_dia/2,
- lock_0y + lock_d/2 + clip_d/2,
+ lock_0y + lock_d/2 + clip_d/2 + front_th/2,
total_h - cliprecess_h - clip_th - clip_d/2 );
}
}
}
+module Bracket(){ //// toplevel
+ difference(){
+ MainPositive();
+ ThroughHoles();
+ }
+}
+
+module TestTopEdge(){ //// toplevel
+ intersection(){
+ translate([0,0, -total_h])
+ translate([0,0, 4])
+ Bracket();
+ translate([-200,-200,0])
+ cube([400,400,100]);
+ }
+}
+
+module TestClipBoltHole(){ //// toplevel
+ intersection(){
+ union(){
+ translate([0, 0, -5])
+ Bracket();
+ translate([-4, lock_0y + lock_d/2 + 1, 0])
+ cube([8, 4, 1.5]);
+ }
+ translate([-200, lock_0y + lock_d/2 + 0.1])
+ cube([400, 400, total_h-20]);
+ }
+}
+
//MainPlan();
+//ClipElevationPositive();
//ClipElevation();
-MainPositive();
-%ThroughHoles();
+//MainPositive();
+//%ThroughHoles();
+//TestTopEdge();
+//TestClipBoltHole();
+
+Bracket();