X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=poster-tube-lid.scad;h=08127cde3bd7f137113fe1c0e384a143b9e21f1a;hb=6a319b7ceeca0d02fbeac92c0737e976919d87a1;hp=b08eae29301f39a1098224adcc4cd3f837d8e942;hpb=849c692eff3162749514a327d14964d9c49be43b;p=reprap-play.git

diff --git a/poster-tube-lid.scad b/poster-tube-lid.scad
index b08eae2..08127cd 100644
--- a/poster-tube-lid.scad
+++ b/poster-tube-lid.scad
@@ -79,6 +79,7 @@ sm_closure_cnr = 3.0;
 
 catch_stalk_h = 4.5;
 catch_stalk_len = 50;
+catch_tip_th = 4;
 catch_head_th = 3;
 
 catch_pin_slop = 0.25; // each side, and above
@@ -91,7 +92,7 @@ catch_stalk_base_width = 15;
 
 catch_knob_dia = 6;
 catch_knob_above_gap = 5;
-catch_knob_height = 5;
+catch_knob_height = 3.0;
 
 catch_stalk_below_gap = 1.0;
 catch_stalk_beside_gap = 2.0;
@@ -199,8 +200,6 @@ echo(bayo_polygon);
 
 // CATCH
 
-//cppy6 = -catch_strap_width * 2/3;
-
 cppxC = 0.41 * sm_inner_rad * TAU;
 
 // catch pin
@@ -214,6 +213,7 @@ cppb = bayo_g + [1,-1] * catch_pin_slop + [1,0] * cpp_adj;
 cppd = [ bayo_n[0]
 	 - catch_pin_slop - catch_pin_slop_x_extra,
 	 -catch_stalk_above_gap ];
+cppi = [ cppa[0], cppd[1] ];
 cppc = [ cppd[0], cppb[1] ];
 cpph = cppd + [0,-1] * catch_stalk_h;
 cppe = cppd + [0,-1] * (catch_knob_above_gap + catch_knob_dia/2);
@@ -239,13 +239,15 @@ cppD = cppC + [0,-1] * catch_strap_width;
 
 // catch assembly stalk and so on
 
+catch_cr3 = catch_cr + catch_stalk_h;
+
 cppF = [ cppg[0] - catch_stalk_eff_bend_rad, cppd[1] ];
 cpp4 = [ cppg[0] - catch_stalk_len, cpph[1] ] + [1,-1] * catch_cr;
 cpp5 = [ cpp4[0], cppC[1] + catch_cr ];
 cpp2 = cpp5 + [-1,0] * (catch_cr * 2 + catch_stalk_base_width);
 cpp2r = cpp2 + [1,0] * catch_cr;
 cpp2d = cpp2 + [0,-1] * catch_cr;
-cpp3 = [ cpp2[0] + catch_cr * 2, cppd[1] - catch_cr ];
+cpp3 = [ cpp2[0] + catch_cr + catch_cr3, cppd[1] - catch_cr3 ];
 cppA = [ -cppxC, cpp9[1] ];
 cppE = [ cppA[0], cppD[1] ];
 
@@ -564,7 +566,7 @@ module CatchAssemblyCoreProfile(){
   difference(){
     union(){
       hull(){
-	translate(cpp3) circle(r= catch_cr);
+	translate(cpp3) circle(r= catch_cr3);
 	polygon([ cpp3,
 		  cpp2r,
 		  cpp5,
@@ -598,9 +600,19 @@ module CatchAssemblyCoreProfile(){
     }
     translate(cpp2) circle(r= catch_cr);
   }
+  // if cpp11 is above cpp10, the subtracted hull above
+  // can go down too far.  Ensure we do not cut off below cppy6.
+  polygon([ cppE,
+	    cppD,
+	    cpp9,
+	    [ cpp9[0],            cppy6 ],
+	    [ cpp7[0] - catch_cr, cppy6 ],
+	    cpp2d
+	    ]);
 }
 
-module CatchHeadProfile(){
+module CatchTipProfile(dy){
+  ddy = [0,dy];
   intersection(){
     translate(cppF){
       difference(){
@@ -609,14 +621,17 @@ module CatchHeadProfile(){
       }
     }
     polygon([ cppa,
-	      cppg,
-	      cpph,
-	      cppd,
+	      cppi + ddy,
+	      cppd + ddy,
 	      cppc,
 	      cppb ]);
   }
+}
+
+module CatchHeadProfile(){
   polygon([ cppd,
-	    cppg,
+	    cppd,
+	    cppi,
 	    cppf,
 	    cppe,
 	    cpph ]);
@@ -627,6 +642,13 @@ module CatchCore(){ /////toplevel
   linear_extrude(height=catch_strap_thick, convexity=10)
     CatchAssemblyCoreProfile();
 
+  hull(){
+    linear_extrude(height=catch_head_th, convexity=10)
+      CatchTipProfile(0);
+    linear_extrude(height=catch_tip_th, convexity=10)
+      CatchTipProfile(catch_tip_th - catch_head_th);
+  }
+
   linear_extrude(height=catch_head_th, convexity=10)
     CatchHeadProfile();