diff --git a/MatterControlLib/DesignTools/Attributes/OrderChildrenByIndexAttribute.cs b/MatterControlLib/DesignTools/Attributes/OrderChildrenByIndexAttribute.cs
new file mode 100644
index 000000000..79c5f83b4
--- /dev/null
+++ b/MatterControlLib/DesignTools/Attributes/OrderChildrenByIndexAttribute.cs
@@ -0,0 +1,38 @@
+/*
+Copyright (c) 2018, Lars Brubaker, John Lewin
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+The views and conclusions contained in the software and documentation are those
+of the authors and should not be interpreted as representing official policies,
+either expressed or implied, of the FreeBSD Project.
+*/
+
+using System;
+
+namespace MatterHackers.MatterControl.DesignTools
+{
+	[AttributeUsage(AttributeTargets.Class)]
+	public class OrderChildrenByIndexAttribute : Attribute
+	{
+	}
+}
\ No newline at end of file
diff --git a/MatterControlLib/PartPreviewWindow/Object3DTreeBuilder.cs b/MatterControlLib/PartPreviewWindow/Object3DTreeBuilder.cs
index e0ca99ae8..8a184ade8 100644
--- a/MatterControlLib/PartPreviewWindow/Object3DTreeBuilder.cs
+++ b/MatterControlLib/PartPreviewWindow/Object3DTreeBuilder.cs
@@ -66,7 +66,14 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 					|| !hideChildren)
 					&& item.Children?.Any() == true)
 				{
-					foreach (var child in item.Children.OrderBy(i => i.Name))
+					var orderChildrenByIndex = item.Source.GetType().GetCustomAttributes(typeof(OrderChildrenByIndexAttribute), true).Any();
+					IEnumerable<IObject3D> children = item.Children;
+
+					if (!orderChildrenByIndex)
+					{
+						children = item.Children.OrderBy(i => i.Name);
+					}
+					foreach (var child in children)
 					{
 						if (child != null
 							&& !child.GetType().GetCustomAttributes(typeof(HideFromTreeViewAttribute), true).Any())