topeak-mtx-tortec-expeditionrack-adapter: fix from v3

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 9727fdfdb23822533c8be2e598e81d3c951f6452..806bc40d4acdf4d390186f944d668caff6f878a8 100644 (file)
--- a/topeak-mtx-tortec-expeditionrack-adapter.scad
+++ b/topeak-mtx-tortec-expeditionrack-adapter.scad
@@ -59,6 +59,10 @@ main_sz_core_z = $strf * 18;
 // "length" in for-aft direction of interaction with rack rail
 min_on_rail_sz_z = $strf * 25;
 
+// when printer produces support
+support_around = 1.7; // how far does the support extend around (in XY)
+support_remnant = 0.75; // how much frass remains attached (Z height)
+
 $fa=10;
 $fs=1;
 
@@ -190,10 +194,18 @@ module StrapBarrelElevation(){
 // Bracket support block, goes up inside bracket
 // Z origin is bolt hole
 module BrkBlock(){
-  linextr( -brk_block_z/2,
-          +brk_block_z/2 ) {
-    rectfromto([ -brk_block_xw/2, adapt_main_top_y - 0.1 ],
-              [ +brk_block_xw/2, 0 ]);
+  difference(){
+    linextr( -brk_block_z/2,
+            +brk_block_z/2 ) {
+      rectfromto([ -brk_block_xw/2, adapt_main_top_y - 0.1 ],
+                [ +brk_block_xw/2, 0 ]);
+    }
+    linextr_y_xz( -50, 10 ) {
+      translate([ 0, brk_block_z + bolt_z ])
+       square(center=true,
+              [ main_sz_x_fam + support_around*2,
+                support_remnant *2 ]);
+    }
   }
 }