From d0fcf567a287b8f0298dbfc6e7e56468744b14d5 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Wed, 18 Oct 2017 23:48:25 +0100
Subject: [PATCH] poster-tube-lid: wip StrapMount

---
 poster-tube-lid.scad | 57 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/poster-tube-lid.scad b/poster-tube-lid.scad
index 25abc81..f687328 100644
--- a/poster-tube-lid.scad
+++ b/poster-tube-lid.scad
@@ -57,8 +57,26 @@ strap_hoop_inside = 10;
 strap_hoop_strlen = 10;
 strap_hoop_elevation = 45;
 
+sm_inner_circum = 239;
+sm_main_thick = 2.5;
+sm_main_width = 25;
+
+sm_bolt_dia = 3.5;
+sm_bolt_shaft = 21.9;
+sm_bolt_head_dia = 6.94 + 1.0;
+sm_bolt_head_thick = 2.14;
+sm_bolt_nut_width = 5.89 + 0.25;
+sm_bolt_nut_thick = 3.68;
+
+sm_bolt_y_clear = 0.5;
+sm_bolt_y_over = 0.5;
+
+sm_closure_cnr = 3.0;
+
 // calculated
 
+TAU = PI*2;
+
 bayo_entry_x = bayo_entry;
 bayo_entry_z = bayo_entry;
 bayo_inramp_x = bayo_entry;
@@ -91,6 +109,19 @@ jig_mark_rad = jig_mark + main_dia/2 + jig_thick;
 handling_dia = oring_bore + oring_thick*2 + min_wall*2;
 handling_angle = 45;
 
+sm_inner_rad = sm_inner_circum / TAU;
+sm_outer_rad = sm_inner_rad + sm_main_thick;
+
+smc_pos = [ 0, sm_inner_rad, 0 ];
+
+smc_bolt_nut_dia = sm_bolt_nut_width / cos(30);
+
+smc_bolt_y = sm_bolt_dia/2 + sm_bolt_y_clear;
+smc_max_y = smc_bolt_y + sm_bolt_y_over
+  + max(sm_bolt_head_dia/2, smc_bolt_nut_dia/2);
+smc_cnr_c_x = sm_bolt_shaft/2 - sm_closure_cnr
+  - max(sm_bolt_head_thick, sm_bolt_nut_thick);
+
 $fs= coarse ? 2.5 : 0.5;
 $fa= coarse ? 5 : 1;
 
@@ -362,6 +393,32 @@ module CoverTest1(){ ////toplevel
   }
 }
 
+module StrapMountBolt(){ ///toplevel
+  // positioned relative to smc_pos
+}
+
+module StrapMount(){ ////toplevel
+  difference(){
+    union(){
+      cylinder(r=sm_outer_rad, h=sm_main_width);
+      translate(smc_pos){
+	linear_extrude(height=sm_main_width, convexity=10){
+	  hull(){
+	    for (m = [0,1]) mirror([m,0,0]) {
+	      translate([-smc_cnr_c_x, smc_max_y - sm_closure_cnr])
+		circle(r=sm_closure_cnr);
+	      translate([-smc_cnr_c_x, -sm_inner_rad])
+		square([1,1]);
+	    }
+	  }
+	}
+      }
+    }
+    translate([0,0,-1])
+      cylinder(r=sm_inner_rad, h=sm_main_width+2);
+  }
+}
+
 //ProfilesDemo();
 //BayonetCutout();
 //MainProfile();
-- 
2.30.2