Ratcheting strap clip

strap_link.scad

@@ -1,5 +1,13 @@
-links_count=6;
-include_terminal=true;
+links_count=6; // [1..20]
+include_terminal=true; // [true,false]
+export=4; // [0:5]
+
+MODEL_DEMO=0;
+MODEL_LINKS=1;
+MODEL_CLIP=2;
+MODEL_CLIP_RATCHETING=3;
+MODEL_CLIP_RATCHETING_A=4;
+MODEL_CLIP_RATCHETING_B=5;
 
 //validation=1;
 VALIDATE_INTERSECTION=1;
@@ -10,6 +18,11 @@ use <BOSL/transforms.scad>
 use <BOSL/shapes.scad>
 include <BOSL/constants.scad>
 
+function is_not_export() = is_undef(export) || export == 0;
+function is_export() = !is_not_export();
+function is_model_strict(m) = is_export() && export == m;
+function is_model(m) = is_not_export() || export == m;
+
 function get_link_segment_size() = [15, 30, 5];
 function get_link_pin_diameter() = 2;
 function get_link_socket_slack() = [1, 4, 1];
@@ -18,6 +31,8 @@ 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];
 
+function get_link_clip_size() = [get_link_pin_diameter()*5, get_link_segment_size().y - 5, get_link_segment_size().z];
+
 echo("===============================");
 echo(str("Strap length: ", (links_count * get_link_segment_size().x), " mm"));
 echo("===============================");
@@ -101,6 +116,127 @@ module link(terminal=false) {
     }
 }
 
+module clip() {
+    socket_size=get_link_socket_size();
+    clip_size=get_link_clip_size();
+    pin_diam=get_link_pin_diameter();
+    slot_slack=get_link_socket_slack();
+    size=[clip_size.x+socket_size.x, clip_size.y, clip_size.z];
+    slot_size=[clip_size.x+slot_slack.x, size.y+1, pin_diam+slot_slack.z];
+    entry_size=[slot_size.x-5, clip_size.y+1, clip_size.z];
+    right(clip_size.x/2)
+    difference() {
+        cuboid(size, fillet=1);
+        cuboid(slot_size, fillet=1);
+        up(entry_size.z/2) cube(entry_size, center=true);
+    }
+}
+
+module clip_ratcheting(ratchet_length=20) {
+    socket_size=get_link_socket_size();
+    clip_size=get_link_clip_size();
+    pin_diam=get_link_pin_diameter();
+    slot_slack=get_link_socket_slack();
+    size=[clip_size.x+socket_size.x, clip_size.y, clip_size.z];
+    slot_size=[clip_size.x+slot_slack.x, size.y+1, pin_diam+slot_slack.z];
+    entry_size=[slot_size.x-5, clip_size.y+1, clip_size.z];
+    //right(clip_size.x/2)
+    module hook() {
+        intersection() {
+            difference() {
+                cuboid(size, fillet=1);
+                cuboid(slot_size, fillet=1);
+                up(entry_size.z/2) cube(entry_size, center=true);
+            }
+            translate([0, -50, -50]) cube([100, 100, 100]);
+        }
+    }
+    module hookRight() {
+        hook();
+    }
+    module hookLeft() {
+        scale([-1, 1, 1]) hook();
+    }
+    wall=2;
+    tooth_size=[2, 2, 3];
+    module tooth() {
+        s=[tooth_size.x, tooth_size.z, tooth_size.y];
+        up(tooth_size.z/2) xrot(-90) right_triangle(s);
+    }
+    module teethFwd() {
+        tooth_count = ratchet_length/tooth_size.x;
+        fwd((clip_size.y-wall*2)/2)
+        right(ratchet_length/2) {
+            for (i=[1:tooth_count]) {
+                left(i*tooth_size.x) tooth();
+            }
+            cap_size=[ratchet_length, tooth_size.y, 1];
+            up(tooth_size.z/2 + cap_size.z/2) left(cap_size.x/2) back(tooth_size.y/2) {
+                difference() {
+                    cube(cap_size, center=true);
+                    translate([0.1, 0.1, 0]) back(tooth_size.y/2) right(ratchet_length/2) zrot(180) tooth();
+                }
+            }
+        }
+    }
+    module teethBack() {
+        scale([1, -1, 1]) teethFwd();
+    }
+    module ratchetLeft() {
+        right(ratchet_length/2) {
+            difference() {
+                cube([ratchet_length, clip_size.y, clip_size.z], center=true);
+                up(wall/2) cube([ratchet_length, clip_size.y-wall*2, clip_size.z], center=true);
+            }
+            teethFwd();
+            teethBack();
+        }
+    }
+    ratchet_tooth_count=3;
+    ratchet_wall=1;
+    module ratchetTeethFront() {
+        module ratchetButton() {
+            size=[3,wall*4,2];
+            up(4) fwd(wall*2 - ratchet_wall) cuboid(size, fillet=1, edges=EDGES_FRONT);
+            up(2) back(wall/2) cube([size.x, wall, tooth_size.z + size.z], center=true);
+        }
+        fwd((clip_size.y-wall*2)/2 - tooth_size.y - 0.5)
+        left(ratchet_length) {
+            for (i=[0:ratchet_tooth_count-1]) {
+               right(i*tooth_size.x) scale([-1,-1,1]) tooth();
+            }
+            ratchetButton();
+        }
+        
+        module ratchetWall() {
+            up(tooth_size.z/2) left(ratchet_length/2 + wall - wall/2) fwd(clip_size.y/2-wall-tooth_size.y-ratchet_wall)
+            down(wall/2+0.5) cube([ratchet_length + wall, ratchet_wall, tooth_size.z], center=true);
+        }
+        ratchetWall();
+    }
+    module ratchetTeethBack() {
+        scale([1,-1,1]) ratchetTeethFront();
+    }
+    module ratchetRight() {
+        left(wall/2) cube([wall, clip_size.y, clip_size.z], center=true);
+        
+        ratchetTeethFront();
+        ratchetTeethBack();
+    }
+    
+    if (is_model(MODEL_CLIP_RATCHETING_A) || is_model(MODEL_CLIP_RATCHETING)) {
+        left(ratchet_length + wall + 1) {
+            hookLeft();
+            left(0.5) ratchetLeft();
+        }
+    }
+    if (is_model(MODEL_CLIP_RATCHETING_B) || is_model(MODEL_CLIP_RATCHETING)) {
+        ratchetRight();
+        hookRight();
+    }
+}
+
+// Export / Demo / Validation:
 segment_size=get_link_segment_size();
 if (!is_undef(validation)) {
     if (validation==VALIDATE_INTERSECTION) {
@@ -121,7 +257,13 @@ if (!is_undef(validation)) {
         }
     }
 } else {
-    for (i = [0:links_count-1]) {
+    if (is_model(MODEL_CLIP)) {
+        left(get_link_clip_size().x) clip();
+    }
+    if (is_model(MODEL_CLIP_RATCHETING) || is_model(MODEL_CLIP_RATCHETING_A) || is_model(MODEL_CLIP_RATCHETING_B)) {
+        left(get_link_clip_size().x) clip_ratcheting();
+    }
+    if (is_model(MODEL_LINKS)) for (i = [0:links_count-1]) {
         terminal=(i==links_count-1) && include_terminal;
         right(i*segment_size.x) link(terminal=terminal);
     }