poster-tube-lid: introduce middle_bot_z (nfc)

[reprap-play.git] / poster-tube-lid.scad

diff --git a/poster-tube-lid.scad b/poster-tube-lid.scad
index 93577660b677b8ffe7bceb31cd5b94aeb4664cab..2e3d6d3d9c2f08b69a9ddf1cae02019c518c58d2 100644 (file)
--- a/poster-tube-lid.scad
+++ b/poster-tube-lid.scad
@@ -1,7 +1,8 @@
 // -*- C -*-
 
 main_dia = 71.2 + 0.50 - 2.26;
-top_thick = 4;
+top_minthick_middle = 4;
+top_minthick_by_oring = 2.5;
 
 main_cnr = 4.0;
 
@@ -13,13 +14,16 @@ rivet_tall = 5.51 + 0.49;
 over_rivet_wall = 0.5;
 side_rivet_gap = 1.5;
 
-bayo_interf = 0.75;
+bayo_interf = 1.25;
 bayo_behind = 3.5;
 bayo_interf_width = 2.0;
 bayo_interf_slope = 0.75;
 
-seal_thick = 0.1;
-seal_recess = [ 2.0, 2.0 ]; // recess depth, recess height
+oring_thick = 5.0;
+oring_bore = 62.0;
+
+oring_upper_embed_angle = 80;
+oring_compress = 0.1; // proportion
 
 side_taper = 1.0;
 
@@ -31,6 +35,7 @@ bayo_slice_size = 1;
 
 brace_hole_width = 1.0;
 brace_above_below = 1.2;
+brace_end_shorter = 0.3;
 
 jig_thick = 1.4;
 jig_hole_dia = 3.0;
@@ -44,11 +49,26 @@ bayo_entry_z = bayo_entry;
 bayo_inramp_x = bayo_entry;
 bayo_inramp_z = bayo_entry;
 
+oring_mid_dia = oring_bore + oring_thick;
+oring_outer_dia = oring_mid_dia + oring_thick;
+
+oring_oblate = (1 - oring_compress);
+
+oring_y_rad = oring_thick/2 * oring_oblate;
+oring_x_rad = oring_thick/2 / oring_oblate;
+
+seal_thick = oring_y_rad * (1 + cos(oring_upper_embed_angle));
+
 side_height = rivet_posn + bayo_behind + rivet_thick/2;
 side_thick = rivet_tall + over_rivet_wall;
 
+top_thick = max(top_minthick_middle,
+               top_minthick_by_oring + oring_y_rad);
+
 top_z = top_thick + seal_thick;
 
+middle_bot_z = top_z - top_minthick_middle;
+
 bayo_entry = bayo_behind / 3.0;
 bayo_top_z = bayo_behind + rivet_thick + bayo_above_gap;
 bayo_entry_ramp = bayo_entry + bayo_interf;
@@ -70,7 +90,8 @@ bayo_l = bayo_m + bayo_interf * [ 1/bayo_interf_slope,  1 ];
 bayo_k = bayo_l + [ bayo_interf_width, 0 ];
 bayo_j = bayo_k + bayo_interf * [ 1/bayo_interf_slope, -1 ];
 bayo_i = bayo_j + [ rivet_width, 0 ];
-bayo_h = [ bayo_i[0], bayo_behind + rivet_thick + bayo_above_gap ];
+bayo_h = [ bayo_i[0], bayo_behind + rivet_thick
+                     + bayo_above_gap + bayo_interf ];
 bayo_g = [ bayo_m[0] - rivet_width, bayo_h[1] ];
 
 bayo_e = [-bayo_p[0], bayo_p[1]] - [rivet_entry_width,0];
@@ -100,27 +121,38 @@ echo(bayo_polygon);
 
 module MainProfile(){
   main_cnr_pos = [ side_thick, top_z ] - [1,1]*main_cnr;
-  translate(main_cnr_pos){
-    intersection(){
-      difference(){
-       circle(r = main_cnr);
-       circle(r = main_cnr * 0.5);
+  difference(){
+    union(){
+      translate(main_cnr_pos){
+       intersection(){
+         difference(){
+           circle(r = main_cnr);
+           circle(r = main_cnr * 0.5);
+         }
+         square([10,10]);
+       }
       }
-      square([10,10]);
+      polygon([[ -11,                   middle_bot_z      ],
+              [ -11,                   top_z             ],
+              [ main_cnr_pos[0],       top_z             ],
+              [ side_thick,            main_cnr_pos[1]   ],
+              [ side_thick,            -side_height      ],
+              [ side_taper,            -side_height      ],
+              [ 0,                     -rivet_posn       ],
+              [ 0,                     seal_thick        ],
+              [ -oring_x_rad,          seal_thick        ],
+              ],
+             convexity=10);
+    }
+    translate([ oring_mid_dia/2 - main_dia/2, 0 ])
+      hull(){
+      translate([ 0, oring_y_rad ])
+       scale([ 1/oring_oblate, oring_oblate ])
+       circle(oring_thick/2);
+      translate([ 0, oring_y_rad*2 - oring_thick/2 ])
+       circle(oring_thick/2);
     }
   }
-  polygon([[ -1,                    seal_thick        ],
-          [ -1,                    top_z             ],
-          [ main_cnr_pos[0],       top_z             ],
-          [ side_thick,            main_cnr_pos[1]   ],
-          [ side_thick,            -side_height      ],
-          [ side_taper,            -side_height      ],
-          [ 0,                     -rivet_posn       ],
-          [ 0,                     -(seal_recess[0] + seal_recess[1]) ],
-          [ seal_recess[0],        -(seal_recess[0]) ],
-          [ seal_recess[0],        seal_thick        ],
-          ],
-         convexity=10);
 }
 
 module RotateProjectSlice(offset, slice_size, nom_rad, real_rad){
@@ -160,8 +192,8 @@ module BayonetCutout(){
 }
 
 module ProfilesDemo(){ ////toplevel
-  translate([-20,0]) MainProfile();
-  polygon(bayo_polygon, convexity=10);
+  translate([-10,0]) MainProfile();
+  translate([+10,0]) polygon(bayo_polygon, convexity=10);
 }
 
 module Cover(){ ////toplevel
@@ -170,8 +202,8 @@ module Cover(){ ////toplevel
       rotate_extrude(convexity=10)
        translate([main_dia/2, 0])
        MainProfile();
-      translate([0,0, seal_thick])
-       cylinder(h= top_thick, r = main_dia/2);
+      translate([0,0, middle_bot_z])
+       cylinder(h= top_minthick_middle, r = main_dia/2 - 10);
     }
     for (r=[0,180])
       rotate([0,0, r])
@@ -181,7 +213,8 @@ module Cover(){ ////toplevel
       rotate([0,0, r]) {
        height = top_thick - brace_above_below*2;
        translate([0,0, seal_thick + brace_above_below + height/2 ])
-       cube(center=true, [ main_dia, brace_hole_width, height ]);
+       cube(center=true, [ oring_bore - brace_end_shorter,
+                           brace_hole_width, height ]);
       }
     }
   }