diff --git a/js/kiri-driver-fdm.js b/js/kiri-driver-fdm.js
index de40955d..fc7cb13c 100644
--- a/js/kiri-driver-fdm.js
+++ b/js/kiri-driver-fdm.js
@@ -41,16 +41,15 @@ var gs_kiri_fdm = exports;
      */
     FDM.slice = function(settings, widget, onupdate, ondone) {
         var spro = settings.process,
-            spri = settings.device,
-            sout = settings.process,
+            sdev = settings.device,
             update_start = time(),
             minSolid = spro.sliceSolidMinArea,
             solidLayers = spro.sliceSolidLayers,
             doSolidLayers = solidLayers && !spro.sliceVase,
-            firstOffset = spri.nozzleSize / 2,
-            shellOffset = spri.nozzleSize * spro.sliceShellSpacing,
+            firstOffset = sdev.nozzleSize / 2,
+            shellOffset = sdev.nozzleSize * spro.sliceShellSpacing,
             fillOffset = shellOffset * settings.synth.fillOffsetMult,
-            fillSpacing = spri.nozzleSize * spro.sliceFillSpacing,
+            fillSpacing = sdev.nozzleSize * spro.sliceFillSpacing,
             sliceFillAngle = spro.sliceFillAngle,
             view = widget.mesh && widget.mesh.newGroup ? widget.mesh.newGroup() : null;
 
@@ -66,8 +65,9 @@ var gs_kiri_fdm = exports;
 
         SLICER.sliceWidget(widget, {
             height: spro.sliceHeight,
-            view:view,
-            firstHeight: sout.firstSliceHeight
+            minHeight: spro.sliceMinHeight,
+            firstHeight: spro.firstSliceHeight,
+            view: view
         }, onSliceDone, onSliceUpdate);
 
         function onSliceUpdate(update) {
@@ -142,7 +142,7 @@ var gs_kiri_fdm = exports;
                     slice.doSupport(spro.sliceSupportOffset, spro.sliceSupportSpan, spro.sliceSupportExtra, supportMinArea, spro.sliceSupportSize, spro.sliceSupportOffset, spro.sliceSupportGap);
                 }, "support");
                 forSlices(0.7, 0.8, function(slice) {
-                    slice.doSupportFill(spri.nozzleSize, spro.sliceSupportDensity, supportMinArea);
+                    slice.doSupportFill(sdev.nozzleSize, spro.sliceSupportDensity, supportMinArea);
                 }, "support");
             }
 
diff --git a/js/kiri-slicer.js b/js/kiri-slicer.js
index 30100c1a..a9a7d9a8 100644
--- a/js/kiri-slicer.js
+++ b/js/kiri-slicer.js
@@ -102,12 +102,15 @@ var gs_kiri_slicer = exports;
         var zMin = options.zmin || Math.floor(bounds.min.z),
             zMax = options.zmax || Math.ceil(bounds.max.z),
             zInc = options.height,
+            zIncMin = options.minHeight,
+            zIncFirst = options.firstHeight || zInc,
             zOff = true ? zInc / 2 : 0,
+            zHeights = [],      // heights for zIndexes in adaptive mode
             zIndexes = [],      // auto-detected z slicing offsets (laser/cam)
+            zOrdered = [],      // ordered list of Z vertices
             zList = {},         // list of z indices for auto slicing (laser)
             zFlat = {},         // area of z offset flat areas (cam)
             zScale,             // bucket span in z units
-            zPos,
             timeStart = time(),
             slices = [],
             zSum = 0.0,
@@ -129,7 +132,7 @@ var gs_kiri_slicer = exports;
             p3 = points[i++];
             zSum += (Math.abs(p1.z - p2.z) + Math.abs(p2.z - p3.z) + Math.abs(p3.z - p1.z));
             // laser auto-detect z slice points
-            if (zInc === 0) {
+            if (zInc === 0 || zIncMin) {
                 countZ(p1.z);
                 countZ(p2.z);
                 countZ(p3.z);
@@ -172,19 +175,22 @@ var gs_kiri_slicer = exports;
             }
         }
 
-        // create zIndexes array (0 = auto-detect)
+        // we need Z ordered list for laser auto or adaptive fdm slicing
+        if (zInc === 0 || zIncMin) {
+            for (var key in zList) {
+                if (!zList.hasOwnProperty(key)) continue;
+                zOrdered.push(parseFloat(key));
+            }
+            zOrdered.sort(function(a,b) { return a - b});
+        }
+
+        // use Z indices in auto slice mode for laser
         if (zInc === 0) {
             // find unique z-index offsets for slicing
-            var key, zl = [];
-            for (key in zList) {
-                if (!zList.hasOwnProperty(key)) continue;
-                zl.push(parseFloat(key));
-            }
-            zl.sort(function(a,b) { return a - b});
-            for (i = 0; i < zl.length-1; i++) {
+            var zl = zOrdered
+            for (i = 0; i < zl.length - 1; i++) {
                 zIndexes.push((zl[i] + zl[i+1]) / 2);
             }
-            zIndexes.sort(function(a,b) { return a - b});
         } else if (options.cam) {
             // re-divide slice height so that top and
             // bottom slices fall exactly on those faces
@@ -202,6 +208,40 @@ var gs_kiri_slicer = exports;
             zIndexes.sort(function(a,b) {
                 return b-a;
             });
+        } else if (zIncMin) {
+            var zPos = zMin + zIncFirst,
+                zOI = 0,
+                zDelta,
+                zDivMin,
+                zDivMax,
+                zStep,
+                nextZ;
+
+            // first slice is fixed
+            zHeights.push(zPos);
+            zIndexes.push(zIncFirst / 2);
+
+            while (zPos < zMax && zOI < zOrdered.length) {
+                nextZ = zOrdered[zOI++];
+                if (zPos >= nextZ) continue;
+                zDelta = nextZ - zPos;
+                if (zDelta < zIncMin) continue;
+
+                zDivMin = Math.floor(zDelta / zIncMin);
+                zDivMax = Math.floor(zDelta / zInc);
+
+                if (zDivMax) {
+                    zStep = zDelta / (zDivMax + 1);
+                } else {
+                    zStep = zDelta;
+                }
+
+                while (zPos < nextZ) {
+                    zHeights.push(zPos + zStep);
+                    zIndexes.push(zPos + zStep / 2);
+                    zPos += zStep;
+                }
+            }
         } else {
             // FDM is the simplest case.  Just offset and slice at
             // predicable offsets.
@@ -216,8 +256,8 @@ var gs_kiri_slicer = exports;
 
         // create a Slice for each z offset in the zIndexes array
         for (var i = 0; i < zIndexes.length; i++) {
-            zPos = zIndexes[i];
-            sliceZ(zPos);
+            // mark the slice height
+            sliceZ(zIndexes[i], zHeights[i]);
             // kill slicing if onupdate() returns 42
             if (onupdate(i / zIndexes.length) === 42) {
                 return ondone(null);
@@ -319,8 +359,9 @@ var gs_kiri_slicer = exports;
          * add to slices array
          *
          * @param {number} z
+         * @param {number} [height] optional real height (fdm)
          */
-        function sliceZ(z) {
+        function sliceZ(z, height) {
             z = UTIL.round(z,5);
 
             // avoid slicing directly on flat faces as it greatly increases
@@ -378,6 +419,7 @@ var gs_kiri_slicer = exports;
             // allow empty slices in CAM swap mode (for topos w/ gaps)
             if (lines.length == 0 && !(options.swapX || options.swapY)) return;
 
+            slice.height = height || z;
             slice.index = slices.length;
             slice.lines = removeDuplicateLines(lines);
 
diff --git a/js/kiri.js b/js/kiri.js
index f332c493..1244e5a4 100644
--- a/js/kiri.js
+++ b/js/kiri.js
@@ -97,6 +97,7 @@ self.kiri.license = exports.LICENSE;
                     outputShortDistance: 1,
                     outputShortFactor: 1,
                     outputFinishFactor: 1,
+                    sliceMinHeight: 1,
                     outputCooling: 1,
                     // detectThinWalls: 1,
                     antiBacklash: 1,
@@ -308,6 +309,7 @@ self.kiri.license = exports.LICENSE;
                 outputShortDistance: 0.0,
                 outputShortFactor: 0.2,
                 outputFinishFactor: 0,
+                sliceMinHeight: 0,
                 detectThinWalls: false,
                 antiBacklash: 2,
                 zHopDistance: 0,
@@ -2511,8 +2513,9 @@ self.kiri.license = exports.LICENSE;
             outputShortDistance: UC.newInput("short segment", {title:"segment length cutoff\nfor short segments\nin millimeters", bound:UC.bound(0,200), convert:UC.toFloat, modes:FDM}),
             outputShortFactor: UC.newInput("short factor", {title:"max speed reduction factor\nfor short segments\nas % of print speed", bound:UC.bound(0.05,1), convert:UC.toFloat, modes:FDM}),
             outputFinishFactor: UC.newInput("finish factor", {title:"% of nozzle diameter to\nshorten finish path by\nvalues of 0-1", bound:UC.bound(0.0,1), convert:UC.toFloat, modes:FDM}),
-            antiBacklash: UC.newInput("anti-backlash", {title: "use micro-movements to cancel\nbacklash during fills\nin millimeters", bound:UC.bound(0,3), convert:UC.toInt, modes:FDM}),
+            sliceMinHeight: UC.newInput("min layer", {title: "enables adaptive slicing with\nthis as the min layer height\nin millimeters\n0 to disable", bound:UC.bound(0,3.0), convert:UC.toFloat, modes:FDM}),
             zHopDistance: UC.newInput("z hop dist", {title: "amount to raise z\non retraction moves\nin millimeters\n0 to disable", bound:UC.bound(0,3.0), convert:UC.toFloat, modes:FDM}),
+            antiBacklash: UC.newInput("anti-backlash", {title: "use micro-movements to cancel\nbacklash during fills\nin millimeters", bound:UC.bound(0,3), convert:UC.toInt, modes:FDM}),
             //detectThinWalls: UC.newBoolean("thin wall fill", onBooleanClick, {title: "detect and fill thin openings\nbetween shells walls", modes:FDM})
 
             gcodeVars: UC.newGroup("gcode", null, {modes:FDM}),
diff --git a/js/license.js b/js/license.js
index 8493363f..23867065 100644
--- a/js/license.js
+++ b/js/license.js
@@ -1,7 +1,7 @@
 var exports = {
     COPYRIGHT:"Copyright (C) 2014-2017 Stewart Allen <stewart@neuron.com> - All Rights Reserved",
     LICENSE:"Unauthorized copying, modification and re-distribution are strictly prohibited without prior written consent.",
-    VERSION:"1.1.7"
+    VERSION:"1.1.8"
 };
 if (!module) var module = {};
 module.exports = exports;
diff --git a/notes.md b/notes.md
index 37643382..6ae9c1aa 100644
--- a/notes.md
+++ b/notes.md
@@ -59,8 +59,6 @@
 
 # FDM todo
 
-* adaptive layer heights
-* preview doesn't show proper z offsets
 * trim support offset from layer below
 * feather sharp tips by reducing extrusion in area of overlap
 * add option to reduce poly speed to match shortest/slowest segment