diff --git a/notes.md b/notes.md
index 400845bd..fc5a2046 100644
--- a/notes.md
+++ b/notes.md
@@ -11,7 +11,7 @@
 * onshape mouse mapping option
 
 ## 2.4
-* cnc: tracing, visualization, manual tabs
+* cnc: tracing, visualization, manual tabs, auto feature detection (slicing)
 * fdm: manual supports, continuous printing
 * all: 2d image to 3d part
 
diff --git a/src/kiri/main.js b/src/kiri/main.js
index 60a92217..9d02379b 100644
--- a/src/kiri/main.js
+++ b/src/kiri/main.js
@@ -1045,7 +1045,6 @@
             wb.max.y += wp.y;
             bounds.union(wb);
         });
-// console.log(JSON.stringify(bounds))
         return settings.bounds = bounds;
     }
 
@@ -1145,13 +1144,17 @@
         }
     }
 
-    function platformLoadSTL(url, onload) {
+    function platformLoadSTL(url, onload, formdata) {
         new MOTO.STL().load(url, function(vertices, filename) {
-            let widget = newWidget().loadVertices(vertices);
-            widget.filename = filename;
-            platform.add(widget);
-            if (onload) onload(vertices, widget);
-        })
+            if (vertices) {
+                let widget = newWidget().loadVertices(vertices);
+                widget.filename = filename;
+                platform.add(widget);
+                if (onload) {
+                    onload(vertices, widget);
+                }
+            }
+        }, formdata);
     }
 
     function platformComputeMaxZ() {
diff --git a/src/kiri/render.js b/src/kiri/render.js
index 1ecc2703..3fbc6104 100644
--- a/src/kiri/render.js
+++ b/src/kiri/render.js
@@ -18,6 +18,10 @@
             };
         }
 
+        getLayer(layer) {
+            return this.layers[layer];
+        }
+
         setLayer(layer, colors, off) {
             let layers = this.layers;
             if (typeof(colors) === 'number') {
diff --git a/src/kiri/stacks.js b/src/kiri/stacks.js
index 8fef07b7..a12b0a95 100644
--- a/src/kiri/stacks.js
+++ b/src/kiri/stacks.js
@@ -43,6 +43,10 @@
 
     }
 
+    function getStack(name) {
+        return stacks[name];
+    }
+
     function create(name, view) {
         if (stacks[name]) {
             return stacks[name];
@@ -254,6 +258,7 @@
     KIRI.stacks = {
         clear,
         create,
+        getStack,
         getRange,
         setRange
     };
diff --git a/src/mode/cam/client.js b/src/mode/cam/client.js
index bded475e..e1ed3794 100644
--- a/src/mode/cam/client.js
+++ b/src/mode/cam/client.js
@@ -162,7 +162,7 @@
         }
 
         const {x, y, z} = stock;
-        if (x && y && z) {
+        if (x && y && z && !STACKS.getStack('bounds')) {
             const render = new KIRI.Render().setLayer('bounds', { face: 0xaaaaaa, line: 0xaaaaaa });
             const stack = STACKS.create('bounds', SPACE.platform.world);
             stack.add(render.addPolys([
diff --git a/src/moto/load-stl.js b/src/moto/load-stl.js
index b247202f..d1cf502b 100644
--- a/src/moto/load-stl.js
+++ b/src/moto/load-stl.js
@@ -26,7 +26,7 @@
     }
 
 
-    SP.load = function(url, callback) {
+    SP.load = function(url, callback, formdata) {
         let stl = this,
             xhr = new XMLHttpRequest();
 
@@ -56,9 +56,9 @@
             xhr.overrideMimeType('text/plain; charset=x-user-defined');
         }
 
-        xhr.open('GET', url, true);
+        xhr.open(formdata ? 'POST' : 'GET', url, true);
         xhr.responseType = 'arraybuffer';
-        xhr.send(null);
+        xhr.send(formdata);
     };
 
     SP.encode = function(vertices, normals) {