diff --git a/ConfigurationPage/PrintLeveling/LevelWizard7PointRadial.cs b/ConfigurationPage/PrintLeveling/LevelWizard7PointRadial.cs
index 15d1d09a4..5e5d01ac7 100644
--- a/ConfigurationPage/PrintLeveling/LevelWizard7PointRadial.cs
+++ b/ConfigurationPage/PrintLeveling/LevelWizard7PointRadial.cs
@@ -115,9 +115,8 @@ namespace MatterHackers.MatterControl.ConfigurationPage.PrintLeveling
 			}
 		}
 
-		internal static string ApplyLeveling(string lineBeingSent, Vector3 currentDestination, PrinterMachineInstruction.MovementTypes movementMode)
+		public static string ApplyLeveling(string lineBeingSent, Vector3 currentDestination, PrinterMachineInstruction.MovementTypes movementMode)
 		{
-			// old ref code
 			if (PrinterConnectionAndCommunication.Instance.ActivePrinter != null
 				&& PrinterConnectionAndCommunication.Instance.ActivePrinter.DoPrintLeveling
 				&& (lineBeingSent.StartsWith("G0 ") || lineBeingSent.StartsWith("G1 "))
@@ -139,6 +138,7 @@ namespace MatterHackers.MatterControl.ConfigurationPage.PrintLeveling
 		
 					if (movementMode == PrinterMachineInstruction.MovementTypes.Relative)
 					{
+						// TODO: this is not correct for 7 point leveling
 						Vector3 relativeMove = Vector3.Zero;
 						GCodeFile.GetFirstNumberAfter("X", lineBeingSent, ref relativeMove.x);
 						GCodeFile.GetFirstNumberAfter("Y", lineBeingSent, ref relativeMove.y);
@@ -167,7 +167,7 @@ namespace MatterHackers.MatterControl.ConfigurationPage.PrintLeveling
 			return lineBeingSent;
 		}
 
-		private static Vector3 GetPositionWithZOffset(Vector3 currentDestination, PrintLevelingData levelingData)
+		public static Vector3 GetPositionWithZOffset(Vector3 currentDestination, PrintLevelingData levelingData)
 		{
 			double angleToPoint = Math.Atan2(currentDestination.y, currentDestination.x);
 
diff --git a/Tests/MatterControl.Tests/MatterControl.Tests.csproj b/Tests/MatterControl.Tests/MatterControl.Tests.csproj
index f898c96ae..c9a149a35 100644
--- a/Tests/MatterControl.Tests/MatterControl.Tests.csproj
+++ b/Tests/MatterControl.Tests/MatterControl.Tests.csproj
@@ -62,6 +62,7 @@
     <Compile Include="MatterControl\SetupIniTests.cs" />
     <Compile Include="MatterControl\Slicing\SliceMappingCLassesTets.cs" />
     <Compile Include="MatterControl\Slicing\SliceLayersTests.cs" />
+    <Compile Include="MatterControl\LevelingTests.cs" />
     <Compile Include="MatterControl\TranslationsTests.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>
diff --git a/Tests/MatterControl.Tests/MatterControl/LevelingTests.cs b/Tests/MatterControl.Tests/MatterControl/LevelingTests.cs
new file mode 100644
index 000000000..ff7fd8b01
--- /dev/null
+++ b/Tests/MatterControl.Tests/MatterControl/LevelingTests.cs
@@ -0,0 +1,62 @@
+using MatterHackers.MatterControl;
+using NUnit.Framework;
+using System;
+using System.IO;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using System.Reflection;
+using System.Text;
+using System.Linq;
+using MatterHackers.MatterControl.ConfigurationPage.PrintLeveling;
+using MatterHackers.VectorMath;
+
+namespace MatterControl.Tests.MatterControl
+{
+
+    [TestFixture]
+    public class LevelingTests
+    {
+        [Test, Category("Leveling")]
+        public void Leveling7PointsCorectInterpolation()
+        {
+			PrintLevelingData levelingData = new PrintLevelingData();
+
+			double radius = 100;
+			levelingData.SampledPositions = new List<Vector3>();
+			Vector2 currentEdgePoint = new Vector2(radius, 0);
+			for (int i = 0; i < 6; i++)
+			{
+				levelingData.SampledPositions.Add(new Vector3(currentEdgePoint, i));
+				currentEdgePoint.Rotate(MathHelper.Tau / 6);
+			}
+
+			levelingData.SampledPositions.Add(new Vector3(0, 0, 6));
+
+			for (int i = 0; i < 6; i++)
+			{
+				// test actual sample position
+				Vector2 currentTestPoint = new Vector2(radius, 0);
+				currentTestPoint.Rotate(MathHelper.Tau / 6 * i);
+				Vector3 outPosition = LevelWizard7PointRadial.GetPositionWithZOffset(new Vector3(currentTestPoint, 0), levelingData);
+				Assert.AreEqual(outPosition.z, levelingData.SampledPositions[i].z, .001);
+
+				// test 1/2 angles (mid way between samples
+				int nextPoint = i < 5 ? i + 1 : 0;
+				currentTestPoint = new Vector2(radius, 0);
+				currentTestPoint.Rotate(MathHelper.Tau / 6 * (i + .5));
+				outPosition = LevelWizard7PointRadial.GetPositionWithZOffset(new Vector3(currentTestPoint, 0), levelingData);
+				Assert.AreEqual(outPosition.z, (levelingData.SampledPositions[i].z + levelingData.SampledPositions[nextPoint].z)/2, .001);
+
+				// test 1/2 to center
+				currentTestPoint = new Vector2(radius / 2, 0);
+				currentTestPoint.Rotate(MathHelper.Tau / 6 * i));
+				outPosition = LevelWizard7PointRadial.GetPositionWithZOffset(new Vector3(currentTestPoint, 0), levelingData);
+				Assert.AreEqual(outPosition.z, (levelingData.SampledPositions[i].z + levelingData.SampledPositions[6].z) / 2, .001);
+			}
+			
+			Vector3 outPosition2 = LevelWizard7PointRadial.GetPositionWithZOffset(Vector3.Zero, levelingData);
+			Assert.AreEqual(outPosition2.z, levelingData.SampledPositions[6].z, .001);
+		}
+    }
+}