From 249a66deaa9fecbe7d45199df1625b0826e747c9 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sat, 5 Nov 2022 00:28:17 +0000
Subject: [PATCH] topeak-mtx-tortec-expeditionrack-adapter: wip

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 topeak-mtx-tortec-expeditionrack-adapter.scad | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/topeak-mtx-tortec-expeditionrack-adapter.scad b/topeak-mtx-tortec-expeditionrack-adapter.scad
index 82c3a8a..8a3d219 100644
--- a/topeak-mtx-tortec-expeditionrack-adapter.scad
+++ b/topeak-mtx-tortec-expeditionrack-adapter.scad
@@ -16,7 +16,7 @@ rear_to_front_distance = 230;
 
 general_gap_y = 1.0;
 
-strap_w = 8.0;
+strap_w = 8.0 + 1.0;
 strap_th = 2.5;
 strap_barrel_dia = 12;
 strap_guide_sz = 2;
@@ -44,6 +44,8 @@ block_y_min = adapt_main_top_y - main_sz_y;
 
 strap_barrel_x = rack_width_inner/2 + strap_barrel_dia/2;
 
+rack_shear_ratio = rear_elevation_nominal / rear_to_front_distance;
+
 module GraspElevation(){
   hull(){
     translate([ grasp_large_x, adapt_main_top_y - grasp_large_r ])
@@ -67,10 +69,11 @@ module MainExtrude(){
     children();
 }
 module RackShear(){
-  multmatrix([ [ 1, 0,   0, 0 ],
-	       [ 0, 1, 0.1, 0 ],
-	       [ 0, 0,   1, 0 ],
-	       [ 0, 0,   0, 1 ] ])
+  s = rack_shear_ratio;
+  multmatrix([ [ 1, 0,  0, 0 ],
+	       [ 0, 1, s , 0 ],
+	       [ 0, 0,  1, 0 ],
+	       [ 0, 0,  0, 1 ] ])
     children();
 }
 
-- 
2.30.2