diff --git a/src/kiri/main.js b/src/kiri/main.js
index 17d14547..0f2d6598 100644
--- a/src/kiri/main.js
+++ b/src/kiri/main.js
@@ -1060,7 +1060,7 @@ console.log/** Copyright Stewart Allen <sa@grid.space> -- All Rights Reserved */
                 factor = (widget.getVertices().count / defvert);
 
             // compensate for zcut (widget moved through floor)
-            widget.stack.obj.view.position.z = widget.track.zcut;
+            widget.stack.obj.view.position.z = widget.track.zcut || 0;
 
             widget.slice(settings, function(sliced, error) {
                 widget.rotinfo = null;
diff --git a/src/kiri/print.js b/src/kiri/print.js
index 41bc39fe..9ea38da4 100644
--- a/src/kiri/print.js
+++ b/src/kiri/print.js
@@ -903,7 +903,7 @@
                 if (!near && !found) {
                     if (start === 0 && lastIndex === -1) {
                         console.log('infinite loop', lines, {
-                            marked, options, i, group, start, lastIndex,
+                            marked, i, group, start, lastIndex,
                             points: lines.map(p => p.index).join(', ')
                         });
                         break;
diff --git a/src/mode/fdm/slice.js b/src/mode/fdm/slice.js
index a7a33904..7402790c 100644
--- a/src/mode/fdm/slice.js
+++ b/src/mode/fdm/slice.js
@@ -545,22 +545,29 @@
                     // and zig/zag lines connectd by shell segments
                     if (!outline) {
                         let newlines = [];
-                        let op1, op2;
+                        let op2;
                         let eo = 0;
+                        let idx = 1;
                         for (let i=0; i<lines.length; i += 2) {
                             let p1 = lines[i];
                             let p2 = lines[i+1];
+                            p1.index = idx;
+                            p2.index = idx++;
                             if (eo++ % 2 === 1) {
                                 let t = p1;
                                 p1 = p2;
                                 p2 = t;
                             }
                             if (op2) {
+                                let op1 = p1.clone();
+                                op1.index = op2.index;
                                 newlines.push(op2);
-                                newlines.push(p1);
+                                newlines.push(op1);
                             }
-                            newlines.push(op1 = p1);
-                            newlines.push(op2 = p2);
+                            newlines.push(p1);
+                            newlines.push(p2);
+                            op2 = p2.clone();
+                            op2.index = idx++;
                         }
                         rec.top.fill_lines = newlines;
                         rec.top.shells = [];