Improve mounting hole pattern for x-end nut trap

* Remove the hole for that interferes with the linear bearings
* Add a trap for an m3 nylon lock nut for the hole that goes into the
  x-end body

The nut trap may cause a tiny hole (~0.6mm tall) to appear in the smooth
rod channel when printing with a 0.5mm nozzle, but the nut will not
contact the smooth rod.

diff --git a/scad/x-end.scad b/scad/x-end.scad
index b32c115..b475840 100644 (file)
--- a/scad/x-end.scad
+++ b/scad/x-end.scad
@@ -22,10 +22,18 @@ module nut_trap () {
                    cylinder(h=12,r=5.45,$fn=50,center=true);
                    // holes for m3 screws in brass nut
                    #translate(v=[8,0,0]) cylinder(h=12,r=1.8,$fn=20,center=true);
-                   #rotate([0,0,90]) translate(v=[8,0,0]) cylinder(h=12,r=1.8,$fn=20,center=true);
-                   #rotate([0,0,180]) translate(v=[8,0,0]) cylinder(h=12,r=1.8,$fn=20,center=true);
-                   #rotate([0,0,270]) translate(v=[8,0,0]) cylinder(h=12,r=1.8,$fn=20,center=true);
-           }
+                  // screw hole would interfere with the linear bearings
+//                   #rotate([0,0,90]) translate(v=[8,0,0]) cylinder(h=12,r=1.8,$fn=20,center=true);
+                  rotate([0,0,180]) {
+                       translate(v=[8,0,0]) cylinder(h=12,r=1.8,$fn=20,center=true);
+                       // add a trap for an m3 nylock nut since this part
+                       // goes inside of the x-end body
+                       translate(v=[8,0,7.25]) rotate ([0,0,180/12])
+                            // $fn = 12 makes it easier to insert the nut
+                            cylinder(h=4.5, r=5.5 / 2 / cos(180 / 6) + 0.1, center=true, $fn=12);
+                  }
+                  #rotate([0,0,270]) translate(v=[8,0,0]) cylinder(h=12,r=1.8,$fn=20,center=true);
+     }
 }
 
 module x_end_base(){