diff --git a/src/kiri-mode/cam/ops.js b/src/kiri-mode/cam/ops.js
index 408ded97..555e469f 100644
--- a/src/kiri-mode/cam/ops.js
+++ b/src/kiri-mode/cam/ops.js
@@ -200,9 +200,6 @@ class OpRough extends CamOp {
                 POLY.offset([ newPolygon().centerRectangle(stock.center, stock.x, stock.y) ], step) :
                 POLY.offset(shadow, roughIn ? step : step + roughLeave + toolDiam / 2);
             let facing = POLY.offset(inset, -step, { count: 999, flat: true });
-            if (isIndexed) {
-                ztOff = (stock.z / 2) - zMax;
-            }
             let zdiv = ztOff / roughDown;
             let zstep = (zdiv % 1 > 0) ? ztOff / (Math.floor(zdiv) + 1) : roughDown;
             if (ztOff === 0) {
diff --git a/src/kiri-mode/cam/slice.js b/src/kiri-mode/cam/slice.js
index 9f0db31a..b2bb1f56 100644
--- a/src/kiri-mode/cam/slice.js
+++ b/src/kiri-mode/cam/slice.js
@@ -52,8 +52,8 @@ CAM.slice = async function(settings, widget, onupdate, ondone) {
         track = widget.track;
         ({ camZTop, camZBottom, camZThru } = proc);
         wztop = track.top;
-        ztOff = isIndexed ? 0 : (stock.z - wztop);
-        zbOff = isIndexed ? 0 : (wztop - track.box.d);
+        ztOff = isIndexed ? (stock.z - bounds.dim.z) / 2 : (stock.z - wztop);
+        zbOff = isIndexed ? (stock.z - bounds.dim.z) / 2 : (wztop - track.box.d);
         zBottom = isIndexed ? camZBottom : camZBottom - zbOff;
         zMin = isIndexed ? bounds.min.z : Math.max(bounds.min.z, zBottom);
         zMax = bounds.max.z;
@@ -125,7 +125,7 @@ CAM.slice = async function(settings, widget, onupdate, ondone) {
         return error('no processes specified');
     }
 
-    if (stock.x && stock.y && stock.z) {
+    if (stock.x && stock.y && stock.z && !isIndexed) {
         if (stock.x + 0.00001 < bounds.max.x - bounds.min.x) {
             return error('stock X too small for part. resize stock or use offset stock');
         }
@@ -291,7 +291,7 @@ CAM.slice = async function(settings, widget, onupdate, ondone) {
         if (op.op.type === "index") {
             widget.topo = undefined;
             // let points = base.verticesToPoints();
-            state.slicer = new kiri.cam_slicer(widget);
+            slicer = state.slicer = new kiri.cam_slicer(widget);
             shadows = {};
             await new CAM.OPS.shadow(state, { type: "shadow", silent: true }).slice(progress => {
                 // console.log('reshadow', progress.round(3));
@@ -471,7 +471,7 @@ CAM.holes = async function(settings, widget, individual, rec,onProgress) {
     let slicerOpts = {flatoff: 0.001}
     let slicer = new kiri.cam_slicer(widget,slicerOpts);
     let zFlats = Object.keys(slicer.zFlat).map(Number).map(z=>[z,z-0.002]).flat()
-    
+
     precision = Math.max( 0, precision )
     let intervals = (precision == 0) ? [] : slicer.interval(
         precision,