diff --git a/assembly.scad b/assembly.scad
index 137ac02..d572e60 100644
--- a/assembly.scad
+++ b/assembly.scad
@@ -57,7 +57,7 @@ module moving_parts(xpos = cur_xpos, ypos = cur_ypos) {
   translate([ yrail_offset, cur_ypos, 0 ]) ysled_slider(spread = sled_ysize);
 
   translate([ xsize - yrail_offset, cur_ypos, 0 ]) rotate([ 180, 180, 0 ])
-      ysled_slider(spread = sled_ysize);
+      ysled_slider(spread = sled_ysize, is_left = false);
 
   translate([ yrail_offset, cur_ypos, 0 ]) if ($preview) ysled_rails();
 
@@ -75,3 +75,9 @@ union() {
   corners();
   moving_parts();
 }
+
+*intersection() {
+  ysled_slider(spread=sled_ysize);
+  translate([0, -1000, -1000])
+  cube([2000, 2000, 2000]);
+}
\ No newline at end of file
diff --git a/lib.scad b/lib.scad
index 72c4254..b74ed9b 100644
--- a/lib.scad
+++ b/lib.scad
@@ -2,4 +2,13 @@ module bom_item(printable = true, label = "") {
   print_label = printable ? " print " : " stock ";
   item_label = label == "" ? parent_module(1) : label;
   echo(str("BOM:", print_label, item_label));
+}
+
+module slotify(vector) {
+  for (child = [0:$children-1]) {
+    hull() {
+      children(child);
+      translate(vector) children(child);
+    }
+  }
 }
\ No newline at end of file
diff --git a/parts.scad b/parts.scad
index 55f46e3..0cff8e0 100644
--- a/parts.scad
+++ b/parts.scad
@@ -25,6 +25,8 @@ belt_height2 = belt_height1 + belt_width + 2;
 
 ysled_rail_spacing = (sled_ysize);
 motor_shaft_xoffset = (corner_size - wall_thickness) / 2;
+motor_mount_length_adjustment = 4;
+motor_mount_length = nema17_face + wall_thickness + motor_mount_length_adjustment;
 
 // Generates bar of length $l, centered on origin extending in +Z
 module tslot(l) {
@@ -39,8 +41,10 @@ module tslot(l) {
 module corner_base() {
   odim = frame_size / 2 + wall_thickness;
   ldim = frame_size / 2 + corner_size;
+
   cap_points = [
-    [ -odim, -odim ], [ -odim, ldim ], [ odim, ldim ], [ ldim, odim ],
+    [ -odim, -odim ], [ -odim, ldim ], [ odim, ldim ],
+    [odim, odim], [ ldim, odim ],
     [ ldim, -odim ]
   ];
   difference() {
@@ -65,17 +69,18 @@ module rail_holder(in_x) {
   tube_offset = (corner_size) / 2 + wall_thickness;
   tube_rotation = in_x ? 90 : 0;
 
-  translated_rail_offset = yrail_offset - frame_size / 2;
+  translated_rail_offset = yrail_offset - frame_size / 2 - wall_thickness;
 
-  translate([ frame_size / 2, frame_size / 2, -frame_size / 2 ]) {
+
+  translate([ frame_size / 2 + wall_thickness, frame_size / 2 + wall_thickness, -frame_size / 2 - wall_thickness ]) {
     difference() {
-      linear_extrude(frame_size)
-          polygon(points = [[wall_thickness, wall_thickness],
-                            [wall_thickness, corner_size],
-                            [corner_size, wall_thickness]]);
-
+      cube([
+        !in_x ? corner_size - wall_thickness : 10,
+        !in_x ? 10 : corner_size - wall_thickness,
+        wall_thickness * 2 + frame_size
+      ]);
       translate(
-          [ translated_rail_offset, translated_rail_offset, frame_size / 2 ])
+          [ translated_rail_offset, translated_rail_offset, frame_size / 2 + wall_thickness ])
           rotate([ tube_rotation - 90, tube_rotation, 0 ])
               translate([ 0, 0, -corner_size ])
                   cylinder(d = rail_diam, corner_size * 4);
@@ -84,7 +89,7 @@ module rail_holder(in_x) {
 }
 
 // centered on the rail.
-module ysled_slider(spread, associated_parts = $preview) {
+module ysled_slider(spread, associated_parts = $preview, is_left=true) {
   bom_item(label = str("ysled_slider(", spread, ")"));
   sled_len = spread + frame_size;
   sled_height = frame_size;
@@ -122,12 +127,12 @@ module ysled_slider(spread, associated_parts = $preview) {
   translate(
       [ pulley_sbend_offset - yrail_offset + motor_shaft_xoffset, 0, 0 ]) {
     translate([ 0, idler_spacing / 2, 0 ]) {
-      idler_post(belt_height = belt_height1);
+      idler_post(belt_height = belt_height1, toothed = is_left);
     }
     translate([ 0, -idler_spacing / 2, 0 ]) {
       *cylinder(d = 3, h = 30, $fs = 1);
       *idler(belt_height2);
-      rotate([ 0, 0, -90 ]) { idler_post(belt_height = belt_height2); }
+      rotate([ 0, 0, -90 ]) { idler_post(belt_height = belt_height2, toothed = !is_left); }
     }
   }
 
@@ -138,25 +143,38 @@ module ysled_slider(spread, associated_parts = $preview) {
   }
 }
 
+
+
 module nema17_housing() {
   hwidth = corner_size + frame_size + wall_thickness;
   hheight = nema17_face + wall_thickness * 2;
   hdepth = frame_size + wall_thickness * 2;
 
   screw_dxy = 31 / 2;
+
   translate([ 0, -nema17_face / 2 - frame_size / 2 - wall_thickness, 0 ])
-      render() difference() {
-    cube([ hwidth, hheight, hdepth ], center = true);
+      slotify([0, -motor_mount_length_adjustment, 0]) {
 
     translate([ 0, 0, -2 ])
         cube([ nema17_face + 1, nema17_face + 1, hdepth ], center = true);
     cylinder(d = 23, frame_size);
 
-    for (x = [ -screw_dxy, screw_dxy ], y = [ -screw_dxy, screw_dxy ])
-      translate([ x, y, frame_size / 2 + wall_thickness ])
-          rotate([ 180, 0, 0 ]) {
-        cylinder(d = 5, h = 3);
-      }
+    translate([ -screw_dxy, -screw_dxy, frame_size / 2 + wall_thickness ])
+        rotate([ 180, 0, 0 ]) {
+      cylinder(d = 5, h = 3);
+    }
+    translate([  screw_dxy, -screw_dxy, frame_size / 2 + wall_thickness ])
+        rotate([ 180, 0, 0 ]) {
+      cylinder(d = 5, h = 3);
+    }
+    translate([ -screw_dxy,  screw_dxy, frame_size / 2 + wall_thickness ])
+        rotate([ 180, 0, 0 ]) {
+      cylinder(d = 5, h = 3);
+    }
+    translate([  screw_dxy,  screw_dxy, frame_size / 2 + wall_thickness ])
+        rotate([ 180, 0, 0 ]) {
+      cylinder(d = 5, h = 3);
+    }
   }
 }
 
@@ -192,21 +210,36 @@ module idler_post(belt_height, toothed = true) {
     cylinder(d = 3, h = total_height + 1, $fn = 60);
     translate([ 0, 0, total_height - 2 ]) cylinder(r = 3, h = 3);
   }
-
-  idler(height = belt_height);
+  
+  idler(height = belt_height, toothed=toothed);
 }
 
 module flcorner() {
   bom_item();
-  rotate([ 0, 0, 0 ]) {
-    corner_base();
-    rail_holder(false);
-  }
-  translate([ (corner_size - wall_thickness) / 2, 0, 0 ]) nema17_housing();
+  render() {
+    rotate([ 0, 0, 0 ]) {
+      corner_base();
+      rail_holder(false);
+    }
+    difference() {
+      translate([
+        -frame_size/2 - wall_thickness,
+        -frame_size/2 - wall_thickness - motor_mount_length,
+        -frame_size/2 - wall_thickness
+        ])
+        cube([
+          frame_size + wall_thickness + corner_size,
+          motor_mount_length,
+          frame_size + wall_thickness * 2
+          ]);
+      translate([ motor_shaft_xoffset, 0, 0 ]) nema17_housing();
 
+    }
+//    translate([motor_shaft_xoffset, 0, 0 ]) nema17_housing();
+  }
   if ($preview)
     translate([
-      (corner_size - wall_thickness) / 2,
+      motor_shaft_xoffset,
       -nema17_face / 2 - frame_size / 2 - wall_thickness, frame_size / 2
     ]) {
       nema17();
@@ -216,15 +249,29 @@ module flcorner() {
 
 module frcorner() {
   bom_item();
-  rotate([ 0, 0, 90 ]) {
-    corner_base();
-    rail_holder(true);
-  }
-  translate([ -(corner_size - wall_thickness) / 2, 0, 0 ]) nema17_housing();
+  render() {
+    rotate([ 0, 0, 90 ]) {
+      corner_base();
+      rail_holder(true);
+    }
+    difference() {
+      translate([
+        -frame_size/2 - corner_size,
+        -frame_size/2 - wall_thickness - motor_mount_length,
+        -frame_size/2 - wall_thickness
+        ])
+        cube([
+          frame_size + wall_thickness + corner_size,
+          motor_mount_length,
+          frame_size + wall_thickness * 2
+          ]);
+      translate([ -motor_shaft_xoffset, 0, 0 ]) nema17_housing();
 
+    }
+  }
   if ($preview)
     translate([
-      -(corner_size - wall_thickness) / 2,
+      -motor_shaft_xoffset,
       -nema17_face / 2 - frame_size / 2 - wall_thickness, frame_size / 2
     ]) {
       nema17();
@@ -236,6 +283,7 @@ module frcorner() {
 
 module blcorner() {
   bom_item();
+  render()
   rotate([ 0, 0, 270 ]) {
     corner_base();
     rail_holder(true);
@@ -244,6 +292,7 @@ module blcorner() {
 
 module brcorner() {
   bom_item();
+  render()
   rotate([ 0, 0, 180 ]) {
     corner_base();
     rail_holder(false);
@@ -325,11 +374,11 @@ module xsled2() {
 
   inner_ysize = sled_ysize - tab_thickness;
 
-  lip_depth = tab_thickness - wall_thickness - glass_thickness;
-  lip_width = glass_thickness;
   film_height = belt_height2 + belt_width / 2;
   ledge_width = 15;
-  inside_ledge_width = ledge_width - 8;
+  inside_ledge_width = 8;
+  outside_ledge_width = ledge_width - inside_ledge_width;
+
 
   film_thickness = 0.25;
 
@@ -341,13 +390,13 @@ module xsled2() {
     [0, film_height + glass_thickness],
     [wall_thickness, film_height + glass_thickness],
     [wall_thickness, film_height],
-    [inside_ledge_width, film_height],
-    [inside_ledge_width, film_height - glass_thickness + 0.5, ],
-    [ledge_width, film_height - glass_thickness + 0.5],
-
+    [outside_ledge_width, film_height],
+    [outside_ledge_width, film_height - glass_thickness],
+    [ledge_width, film_height - glass_thickness],
+    [wall_thickness * 2, -tab_thickness / 2]
   ];
 
-  echo("Ledge width: ", ledge_width - inside_ledge_width);
+  echo("Ledge width: ", ledge_width - outside_ledge_width);
   for (xsign = [ 1, -1 ], ysign = [ 1, -1 ]) {
     translate([ sled_xsize / 2 * xsign, sled_ysize / 2 * ysign, 0 ])
         rotate([ 0, -90 * xsign, 0 ]) {
@@ -388,6 +437,16 @@ module xsled2() {
                 linear_extrude(inner_ysize) polygon(glass_holder_points);
       }
 
+      for (x = [ -1, 1],
+           y = [ -1, 1]) {
+        translate([x * (sled_xsize/2 - outside_ledge_width - inside_ledge_width / 2),
+                   y * (inner_ysize/2 - outside_ledge_width - inside_ledge_width / 2),
+                   film_height])
+        rotate([180,0,0]) {
+          cylinder(d=4, h = 50);
+          cylinder(d=5, h = 4 + glass_thickness );
+        }
+      }
       translate([
         -10, -inner_ysize / 2,
         
@@ -403,8 +462,8 @@ module xsled2() {
         [ 0, 0, film_height - glass_thickness / 2 + 0.5 ])
         cube(
             [
-              sled_xsize - inside_ledge_width * 2,
-               inner_ysize - inside_ledge_width * 2,
+              sled_xsize - outside_ledge_width * 2,
+               inner_ysize - outside_ledge_width * 2,
               glass_thickness
             ],
             center = true);
@@ -427,4 +486,4 @@ module xsled2() {
 }
 
 // render()
-// xsled2();
+// xsled2();
\ No newline at end of file
diff --git a/stock_parts.scad b/stock_parts.scad
index 44a2b43..90889b6 100644
--- a/stock_parts.scad
+++ b/stock_parts.scad
@@ -1,7 +1,7 @@
 include <MCAD/math.scad>
 include <lib.scad>
 
-stock_color = "#aaa4";
+stock_color = "#aaa";
 
 bushing_od = 15;
 bushing_id = 8;
@@ -59,7 +59,7 @@ belt_backing = 0.63 - belt_pld;
 tooth_height = 0.75;
 
 pulley_od = 13;
-pulley_clearance_rad = pulley_od / 2 + 2.5;
+pulley_clearance_rad = pulley_od / 2 + 1.5;
 
 module pulley(teeth, lrim, urim, belt_width, shaft = 5, toothed = true,
               od = 0) {