diff --git a/MatterControlLib/PartPreviewWindow/View3D/Actions/CombineObject3D_2.cs b/MatterControlLib/PartPreviewWindow/View3D/Actions/CombineObject3D_2.cs
index c1d57c535..b8b264048 100644
--- a/MatterControlLib/PartPreviewWindow/View3D/Actions/CombineObject3D_2.cs
+++ b/MatterControlLib/PartPreviewWindow/View3D/Actions/CombineObject3D_2.cs
@@ -147,15 +147,6 @@ namespace MatterHackers.MatterControl.PartPreviewWindow.View3D
 
             var totalOperations = touchingSets.Sum(t => t.Count);
 
-#if false
-			var resultsMesh = BooleanProcessing.DoArray(items,
-				CsgModes.Union,
-				Processing,
-				InputResolution,
-				OutputResolution,
-				reporter,
-				cancellationToken);
-#else
             double amountPerOperation = 1.0 / totalOperations;
             double ratioCompleted = 0;
 
@@ -169,6 +160,16 @@ namespace MatterHackers.MatterControl.PartPreviewWindow.View3D
 
                 if (set.Count > 1)
                 {
+#if false
+                    setMesh = BooleanProcessing.DoArray(set.Select(i => (i.mesh, i.matrix)),
+                        CsgModes.Union,
+                        Processing,
+                        InputResolution,
+                        OutputResolution,
+                        reporter,
+                        cancellationToken);
+#else
+
                     bool first = true;
                     foreach (var next in set)
                     {
@@ -203,6 +204,7 @@ namespace MatterHackers.MatterControl.PartPreviewWindow.View3D
                         progressStatus.Progress0To1 = ratioCompleted;
                         reporter?.Report(progressStatus);
                     }
+#endif
 
                     setMeshes.Add(setMesh);
                 }
@@ -229,7 +231,6 @@ namespace MatterHackers.MatterControl.PartPreviewWindow.View3D
                     resultsMesh.CopyAllFaces(setMesh, Matrix4X4.Identity);
                 }
             }
-#endif
 
             if (resultsMesh != null)
             {
diff --git a/MatterControlLib/PartPreviewWindow/View3D/Actions/SubtractObject3D_2.cs b/MatterControlLib/PartPreviewWindow/View3D/Actions/SubtractObject3D_2.cs
index 9d7dcbaf9..22135eb91 100644
--- a/MatterControlLib/PartPreviewWindow/View3D/Actions/SubtractObject3D_2.cs
+++ b/MatterControlLib/PartPreviewWindow/View3D/Actions/SubtractObject3D_2.cs
@@ -257,7 +257,7 @@ namespace MatterHackers.MatterControl.PartPreviewWindow.View3D
 				foreach (var keep in keepItems)
 				{
 #if false
-					var items = removeVisibleItems.Select(i => (i.Mesh, i.WorldMatrix(SourceContainer))).ToList();
+					var items = removeItems.Select(i => (i.Mesh, i.WorldMatrix(SourceContainer))).ToList();
 					items.Insert(0, (keep.Mesh, keep.Matrix));
 					var resultsMesh = BooleanProcessing.DoArray(items,
 						CsgModes.Subtract,
diff --git a/MatterControlLib/PartPreviewWindow/View3D/View3DWidget.cs b/MatterControlLib/PartPreviewWindow/View3D/View3DWidget.cs
index 9cd362eef..bdf58848b 100644
--- a/MatterControlLib/PartPreviewWindow/View3D/View3DWidget.cs
+++ b/MatterControlLib/PartPreviewWindow/View3D/View3DWidget.cs
@@ -748,7 +748,10 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 			Tuple<double, double> nearFar = null;
 			foreach (var aabb in Object3DControlLayer.MakeListOfObjectControlBoundingBoxes())
 			{
-				nearFar = ExpandNearAndFarToClippedBounds(nearFar, world.IsOrthographic, worldspacePlanes, world.ModelviewMatrix, aabb);
+				if (!double.IsNaN(aabb.MinXYZ.X) && !double.IsInfinity(aabb.MinXYZ.X))
+				{
+					nearFar = ExpandNearAndFarToClippedBounds(nearFar, world.IsOrthographic, worldspacePlanes, world.ModelviewMatrix, aabb);
+				}
 			}
 			nearFar = ExpandNearAndFarToClippedBounds(nearFar, world.IsOrthographic, worldspacePlanes, world.ModelviewMatrix, Object3DControlLayer.GetPrinterNozzleAABB());
 			nearFar = ExpandNearAndFarToClippedBounds(nearFar, world.IsOrthographic, worldspacePlanes, world.ModelviewMatrix, Scene.GetAxisAlignedBoundingBox());