Improve linked strap parametrization

strap_link.scad

@@ -1,4 +1,5 @@
-links_count=14;
+links_count=6;
+include_terminal=true;
 
 //validation=1;
 VALIDATE_INTERSECTION=1;
@@ -12,6 +13,10 @@ include <BOSL/constants.scad>
 function get_link_segment_size() = [15, 30, 5];
 function get_link_pin_diameter() = 2;
 function get_link_socket_slack() = [1, 4, 1];
+function get_link_joiner_arm_size() = [get_link_segment_size().x - 2, 3, segment_size.z];
+function get_link_socket_size() = [get_link_segment_size().z,
+        get_link_segment_size().y - get_link_joiner_arm_size().y*2,
+        get_link_segment_size().z];
 
 echo("===============================");
 echo(str("Strap length: ", (links_count * get_link_segment_size().x), " mm"));
@@ -20,7 +25,7 @@ echo("===============================");
 assert(get_link_segment_size().x >= 10, "Link segment is too short.");
 assert(get_link_segment_size().z >= (get_link_pin_diameter() + get_link_socket_slack().z + 1), "Link segment is too thin.");
 
-module link() {
+module link(terminal=false) {
     segment_size=get_link_segment_size();
     module pin() {
         h=segment_size.y;
@@ -45,7 +50,7 @@ module link() {
     }
     module joiner() {
         gap=2;
-        arm_size=[8, 3, segment_size.z];
+        arm_size=get_link_joiner_arm_size();
         module arm() {
             fwd(segment_size.y/2 + arm_size.y/2 - 1) right(arm_size.x/2 - 1) cuboid(arm_size, fillet=1, edges=EDGES_FRONT + EDGES_Y_ALL);
         }
@@ -56,11 +61,11 @@ module link() {
             scale([1, -1, 1]) arm();
         }
         module armJoiner() {
-            joiner_size=[arm_size.x*0.48, segment_size.y, segment_size.z];
-            right(joiner_size.x + 1) cuboid(joiner_size, fillet=1, edges=EDGES_Z_ALL + EDGES_BOTTOM);
+            joiner_size=[arm_size.x-get_link_socket_size().x, segment_size.y, segment_size.z];
+            right(joiner_size.x/2 + get_link_socket_size().x/2 + gap) cuboid(joiner_size, fillet=1, edges=EDGES_Z_ALL + EDGES_BOTTOM);
         }
         module socketJoiner() {
-            joiner_size=[segment_size.x-4,
+            joiner_size=[segment_size.x-get_link_socket_size().x+get_link_socket_size().x*0.2,
                 segment_size.y-4,
                 segment_size.z];
             difference() {
@@ -68,15 +73,32 @@ module link() {
                 right(segment_size.x) scale([1, 2, 1]) pin_socket_area();
             }
         }
-        socketJoiner();
+        module terminalArm() {
+            left(5) {
+                shift=arm_size.x - get_link_pin_diameter();
+                right(segment_size.x + shift + gap/2) pin();
+                right(segment_size.x + gap/2) {
+                   armFront();
+                   armBack();
+                }
+                right(arm_size.x - get_link_socket_size().x + gap) armJoiner();
+            }
+        }
         armFront();
         armBack();
         armJoiner();
+        if (terminal) {
+            terminalArm();
+        } else {
+            socketJoiner();
+        }
     }
     
     pin();
-    right(segment_size.x) pin_socket();
     joiner();
+    if (!terminal) {
+        right(segment_size.x) pin_socket();
+    }
 }
 
 segment_size=get_link_segment_size();
@@ -100,7 +122,8 @@ if (!is_undef(validation)) {
     }
 } else {
     for (i = [0:links_count-1]) {
-        right(i*segment_size.x) link();
+        terminal=(i==links_count-1) && include_terminal;
+        right(i*segment_size.x) link(terminal=terminal);
     }
 }