more snap fit improvements, update example image

examples/snap_fit_test.scad

@@ -3,25 +3,29 @@ include <jl_scad/parts.scad>
 include <jl_scad/utils.scad>
 
 $slop = 0.1;
-$fn = $preview?16:24;
+$fn = $preview?16:48;
 
-sz = [20,20,15];
+sz = [30,30,10];
 
-//cut_inspect(BACK,color="green",ofs=0)
-box_make(explode=10.01,hide_box=false)
+cut_inspect(BACK,color="black",ofs=0,s=200)
+box_make(explode=10.1,hide_box=false)
 {
     // snap fits
-    box_shell_base_lid(sz,wall_sides=2,wall_top=1.2,rbot_inside=1,rtop_inside=1,rsides=8,rim_height=5,k=0.6)
+    xcopies(sz.x+10,2)
+    box_shell_base_lid(sz,wall_sides=2,wall_top=1.2,rbot_inside=1,rtop_inside=1,rsides=15,rim_height=3,k=0.5)
     {
-        up($box_rim_height) {
-            box_part([BACK,FRONT])
-                box_snap_fit([5,2],spring_len=5,spring_dir=FRONT,thru_hole=true);
+        if($idx == 0)
+            up($box_rim_height) {
+                box_part([LEFT,RIGHT])
+                    box_snap_fit([5,2],spring_len=4,spring_dir=FRONT,thru_hole=false,depth=0.6,spring_slot2=5);
 
-             box_part([LEFT,RIGHT])
-                box_snap_fit([3,2]);
-        }
+            }
+        else
+            up($box_rim_height/2)
+                box_part([LEFT,RIGHT])
+                    box_snap_fit([5,1],spring_len=0,depth=0.2,spring_dir=LEFT,anchor=BOT);
     }
 
     // rim snap
-    right(sz.x+10) box_shell_base_lid(sz,wall_sides=2,wall_top=1.2,rbot_inside=1,rtop_inside=1,rsides=8,rim_height=3,k=0.6,rim_snap=true,rim_snap_gap=0);
+    right(sz.x*1.5+15) box_shell_base_lid(sz,wall_sides=2,wall_top=1.2,rbot_inside=1,rtop_inside=1,rsides=15,rim_height=3,k=0.5,rim_snap=true);
 }

parts.scad

@@ -139,9 +139,12 @@ module box_wall(dir=BACK,height,length,gap=0,width=1,fillet=1.5,anchor=BOTTOM,sp
         cuboid([width,l,height],rounding=-fillet,edges=edges,anchor=anchor,spin=spin,orient=orient);
 }
 
-module box_snap_fit(size=[3,2],depth=0.5,thickness,thru_hole=false,spring_len=3,spring_dir=LEFT,spring_slot=0.5,anchor=BOT+BACK,spin=0,orient=DOWN) {
+module box_snap_fit(size=[3,2],depth=0.5,thickness,thru_hole=false,spring_len=3,spring_dir=FRONT,spring_slot=0.5,spring_slot2,gap=0.1,anchor=BOT+BACK,spin=0,orient=DOWN) {
+    checks = assert(depth<=size.y/2);
+
     thickness = is_def(thickness) ? thickness : is_def($box_wall) ? $box_wall/2 : 1;
     s = (spring_dir.y != 0 ? size : [size.y, size.x]) + [0,spring_len];
+    spring_slot2 = default(spring_slot2, spring_slot);
 
     module snap_shape(slop=0,thru=false) {
         sz = size + [slop,slop];
@@ -155,12 +158,12 @@ module box_snap_fit(size=[3,2],depth=0.5,thickness,thru_hole=false,spring_len=3,
         box_half(BOT) {
             tag(BOX_KEEP_TAG) snap_shape()
             if(spring_len) box_cut() {
-                position(FRONT) back(0.001) cuboid([s.x+spring_slot*2,s.y+spring_slot,thickness+1],rounding=spring_slot/2,edges="Z",anchor=FRONT);
+                position(FRONT) back(0.001) cuboid([s.x+spring_slot*2,s.y+spring_slot2,thickness+1],rounding=spring_slot/2,edges="Z",anchor=FRONT);
             }
         }
 
         box_half(TOP)
-            box_cut() down(0.001) snap_shape(spring_len /*&& !thru_hole*/ ? 0 : get_slop(), thru=thru_hole);
+            box_cut() down(0.001) fwd(gap) snap_shape(spring_len /*&& !thru_hole*/ ? 0 : get_slop(), thru=thru_hole);
 
         children();
     }
@@ -288,10 +291,10 @@ module box_shell_base_lid(
     rbot_inside,
     rtop_inside,
     rim_snap=false, // do a snap ridge around the rim
-    rim_snap_ofs=0.8, // offset along rim Z
-    rim_snap_depth=0.3, // how much the snap ridge should protrude
-    rim_snap_gap=0, // offset the snap rim in base and lid so they match before the lid is fully closed
-    rim_snap_height=0.2,
+    rim_snap_ofs=1, // offset along rim Z
+    rim_snap_depth=0.2, // how much the snap ridge should protrude
+    rim_snap_gap=0.1, // offset the snap rim in base and lid so they match before the lid is fully closed
+    rim_snap_height=0.2, // extra snap height
 ){
     size = scalar_vec3(size);
     wall_top = default(wall_top, wall_sides);