topeak-mtx-tortec-expeditionrack-adapter: conditional prong

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 f2bdf45f9f379954da73d79e6219fee5981fe581..f5dce9da7201e552428562da7cc2ddf3b64b81c6 100644 (file)
--- a/topeak-mtx-tortec-expeditionrack-adapter.scad
+++ b/topeak-mtx-tortec-expeditionrack-adapter.scad
@@ -332,8 +332,10 @@ module Principal(){
       }
 
       FamLinextr(){
-       rectfromto([ -foreaftmaint_top_block_zs[0] + bolt_z, 0 ],
-                  [ -foreaftmaint_top_block_zs[1] + bolt_z, block_y_min] );
+       if ($foreaftmaint_rail_z > foreaftmaint_top_block_zs[0] - bolt_z) {
+         rectfromto([ -foreaftmaint_top_block_zs[0] + bolt_z, 0 ],
+                    [ -foreaftmaint_top_block_zs[1] + bolt_z, block_y_min] );
+       }
        FamGraspElevation();
       }
       intersection(){