topeak-mtx-tortec-expeditionrack-adapter: wip

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/topeak-mtx-tortec-expeditionrack-adapter.scad b/topeak-mtx-tortec-expeditionrack-adapter.scad
index e6e897deb63de145ece01ad734b1935e047f426a..0c31b168c3f7c103f1923ee99f96cc7d4b245ab4 100644 (file)
--- a/topeak-mtx-tortec-expeditionrack-adapter.scad
+++ b/topeak-mtx-tortec-expeditionrack-adapter.scad
@@ -18,7 +18,8 @@ general_gap_y = 1.0;
 
 strap_w = 8.0;
 strap_th = 2.5;
-strap_barrel_dia = 8;
+strap_barrel_dia = 12;
+strap_guide_sz = 2;
 
 main_sz_y = 20;
 grasp_sz = 12;
@@ -41,6 +42,8 @@ grasp_large_x = rack_rail_outer_x + grasp_large_r;
 block_x = grasp_large_x + grasp_large_r/2;
 block_y_min = adapt_main_top_y - main_sz_y;
 
+strap_barrel_x = rack_width_inner/2 + strap_barrel_dia/2;
+
 module GraspElevation(){
   hull(){
     translate([ grasp_large_x, adapt_main_top_y - grasp_large_r ])
@@ -61,7 +64,11 @@ module BlockElevation(){
 
 module GraspFixingElevation(){
   intersection(){
-    mirror([1,0]) GraspElevation();
+    union(){
+      mirror([1,0]) GraspElevation();
+      translate([ strap_barrel_x, $strap_barrel_y ])
+       circle(strap_barrel_dia/2 + strap_guide_sz);
+    }
     union(){
       rectfromto([0, $rack_rail_y],
                 [rack_width_inner, 50]);
@@ -79,8 +86,7 @@ module GraspFixingElevation(){
 }
 
 module StrapBarrelElevation(){
-  translate([ rack_width_inner/2 + strap_barrel_dia/2,
-             $rack_rail_y + rack_rail_dia/2 + strap_barrel_dia/2 ])
+  translate([ strap_barrel_x, $strap_barrel_y ])
     circle(strap_barrel_dia/2);
 }
 
@@ -89,6 +95,8 @@ module Principal(){
   $rack_rail_y = brk_bottom_y - $elevation_nominal
     - general_gap_y  - rack_rail_dia/2;
 
+  $strap_barrel_y = $rack_rail_y + rack_rail_dia/2 + strap_barrel_dia/2;
+
   difference(){
     union(){
       linextr(0, main_sz_z){