diff --git a/MatterControl.Printing/MatterControl.Printing.csproj b/MatterControl.Printing/MatterControl.Printing.csproj
index b2bffebd3..f6a13891a 100644
--- a/MatterControl.Printing/MatterControl.Printing.csproj
+++ b/MatterControl.Printing/MatterControl.Printing.csproj
@@ -17,6 +17,7 @@
     </ProjectReference>
     <ProjectReference Include="..\Submodules\agg-sharp\agg\Agg.csproj">
     </ProjectReference>
+    <ProjectReference Include="..\Submodules\agg-sharp\DataConverters3D\DataConverters3D.csproj" />
     <ProjectReference Include="..\Submodules\agg-sharp\Localizations\Localizations.csproj" />
     <ProjectReference Include="..\Submodules\agg-sharp\VectorMath\VectorMath.csproj">
     </ProjectReference>
diff --git a/MatterControl.Printing/Settings/IObjectSlicer.cs b/MatterControl.Printing/Settings/IObjectSlicer.cs
new file mode 100644
index 000000000..b1f9a1b15
--- /dev/null
+++ b/MatterControl.Printing/Settings/IObjectSlicer.cs
@@ -0,0 +1,39 @@
+/*
+Copyright (c) 2019, 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.IO;
+using MatterHackers.DataConverters3D;
+
+namespace MatterHackers.MatterControl.SlicerConfiguration
+{
+	public interface IObjectSlicer
+	{
+		bool Slice(IObject3D object3D, PrinterSettings printerSettings, Stream outputStream);
+	}
+}
diff --git a/MatterControl.Printing/Settings/PrinterSettings.cs b/MatterControl.Printing/Settings/PrinterSettings.cs
index da38fd08c..75995495d 100644
--- a/MatterControl.Printing/Settings/PrinterSettings.cs
+++ b/MatterControl.Printing/Settings/PrinterSettings.cs
@@ -34,6 +34,7 @@ using System.Linq;
 using System.Text;
 using MatterHackers.Agg;
 using MatterHackers.MatterControl.SlicerConfiguration.MappingClasses;
+using MatterHackers.DataConverters3D;
 using MatterHackers.VectorMath;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Converters;
@@ -72,6 +73,9 @@ namespace MatterHackers.MatterControl.SlicerConfiguration
 
 	public class PrinterSettings
 	{
+		// TODO: Move to more appropriate location after more consideration
+		public static IObjectSlicer ExternalSlicer { get; set; }
+
 		// Latest version should be in the form of:
 		// Year|month|day|versionForDay (to support multiple revisions on a given day)
 		public static int LatestVersion { get; } = 201606271;
diff --git a/MatterControlLib/SlicerConfiguration/Slicer.cs b/MatterControlLib/SlicerConfiguration/Slicer.cs
index 6336db487..48a24f779 100644
--- a/MatterControlLib/SlicerConfiguration/Slicer.cs
+++ b/MatterControlLib/SlicerConfiguration/Slicer.cs
@@ -328,6 +328,26 @@ namespace MatterHackers.MatterControl.SlicerConfiguration
 						matrixAndMeshArgs.Append($" \"{fileName}\" ");
 					}
 
+					// Map from PrinterSettings to PrintSettings
+					if (PrinterSettings.ExternalSlicer != null)
+					{
+						var children = stlFileLocations.Select(s => new Object3D()
+						{
+							MeshPath = s.fileName,
+							Matrix = s.matrix
+						});
+
+						using (var outputStream = File.OpenWrite(gcodeFilePath))
+						{
+							PrinterSettings.ExternalSlicer.Slice(
+								new Object3D(children),
+								printer.Settings,
+								outputStream);
+						}
+
+						return Task.FromResult(true);
+					}
+
 					printer.EngineMappingsMatterSlice.WriteSliceSettingsFile(
 						configFilePath,
 						new[]
diff --git a/PrusaI3-MK3/Defaults.txt b/PrusaI3-MK3/Defaults.txt
new file mode 100644
index 000000000..3be61a390
--- /dev/null
+++ b/PrusaI3-MK3/Defaults.txt
@@ -0,0 +1,79 @@
+{
+  "BridgeExtrudeSpeedX": 0.5,
+  "BridgeFillNozzleDiamStepX": 0.85,
+  "BridgeVolumeScale": 1.0,
+  "CarefulExtrudeSpeed": 1200.0,
+  "ClassTypeName": "gs.info.PrusaSettings",
+  "ClipSelfOverlaps": false,
+  "EnableBridging": true,
+  "EnableRetraction": true,
+  "EnableSupportReleaseOpt": true,
+  "EnableSupportShell": true,
+  "ExtruderTempC": 200,
+  "FanSpeedX": 1.0,
+  "FloorLayers": 2,
+  "GenerateSupport": true,
+  "HeatedBedTempC": 60,
+  "Identifier": "Defaults",
+  "InteriorSolidRegionShells": 0,
+  "LayerHeightMM": 0.2,
+  "Machine": {
+    "ManufacturerName": "Prusa",
+    "ManufacturerUUID": "4530287d-cd23-416c-b74b-4876c385750a",
+    "ModelIdentifier": "i3 MK3",
+    "ModelUUID": "fc09f99c-aee0-45e9-bca3-3e088ccb0b55",
+    "Class": "PlasticFFFPrinter",
+    "BedSizeXMM": 250.0,
+    "BedSizeYMM": 210.0,
+    "MaxHeightMM": 200.0,
+    "FilamentDiamMM": 1.75,
+    "NozzleDiamMM": 0.4,
+    "MinExtruderTempC": 20,
+    "MaxExtruderTempC": 300,
+    "HasHeatedBed": true,
+    "MinBedTempC": 0,
+    "MaxBedTempC": 120,
+    "MinLayerHeightMM": 0.05,
+    "MaxLayerHeightMM": 0.35,
+    "EnableAutoBedLeveling": true,
+    "HasAutoBedLeveling": true,
+    "MaxExtrudeSpeedMMM": 4800,
+    "MaxRetractSpeedMMM": 2100,
+    "MaxTravelSpeedMMM": 7200,
+    "MaxZTravelSpeedMMM": 15000,
+    "MinPointSpacingMM": 0.1
+  },
+  "MaxBridgeWidthMM": 10.0,
+  "MinExtrudeSpeed": 1200.0,
+  "MinLayerTime": 5.0,
+  "MinRetractTravelLength": 2.5,
+  "ModelEnum": "i3_MK3",
+  "OuterPerimeterSpeedX": 0.5,
+  "OuterShellLast": false,
+  "RapidExtrudeSpeed": 4800.0,
+  "RapidTravelSpeed": 7200.0,
+  "RetractDistanceMM": 0.7,
+  "RetractSpeed": 2100.0,
+  "RoofLayers": 2,
+  "SelfOverlapToleranceX": 0.75,
+  "Shells": 2,
+  "ShellsFillNozzleDiamStepX": 1.0,
+  "SolidFillBorderOverlapX": 0.25,
+  "SolidFillNozzleDiamStepX": 1.0,
+  "SparseFillBorderOverlapX": 0.25,
+  "SparseLinearInfillStepX": 5.0,
+  "StartLayerHeightMM": 0.0,
+  "StartLayers": 0,
+  "SupportAreaOffsetX": -0.5,
+  "SupportMinDimension": 1.5,
+  "SupportMinZTips": true,
+  "SupportOverhangAngleDeg": 35.0,
+  "SupportPointDiam": 2.5,
+  "SupportPointSides": 4,
+  "SupportRegionJoinTolX": 2.0,
+  "SupportReleaseGap": 0.20000000298023224,
+  "SupportSolidSpace": 0.34999999403953552,
+  "SupportSpacingStepX": 5.0,
+  "SupportVolumeScale": 1.0,
+  "ZTravelSpeed": 15000.0
+}
\ No newline at end of file