diff --git a/resources/data/printer_gantries/geometries.json b/resources/data/printer_gantries/geometries.json
index 1d8a7b24bb..ed55f5642d 100644
--- a/resources/data/printer_gantries/geometries.json
+++ b/resources/data/printer_gantries/geometries.json
@@ -66,6 +66,14 @@
                 {
                     "height": "7",
                     "type": "convex",
+                    "polygons": [	    
+			"-48,-15; 24,-15; 24,66; -48,66",
+			"-37,-47; 40,-47; 40,21; -37,21"
+                    ]
+                },						
+                {
+                    "height": "32",
+                    "type": "convex",
                     "polygons": [	    
                         "-49,7; 27,7; 27,83; -49,83",			
 			"-42,-46; 40,-46; 40,14; -42,14"			
@@ -192,14 +200,14 @@
                     "type": "convex",
                     "polygons": [
                         "-10,-47;34,-47;34,16;-10,16",
-                        "-34,13;32,13;32,67;-34,67"
+			"-43,11;28,11;28,66;-43,66"			
                     ]
                 },
                 {
                     "height": "23",
                     "type": "convex",
                     "polygons": [
-                        "-42,11;32,11;32,66;-42,66",
+			"-43,11;28,11;28,66;-43,66",
                         "-33,-37;43,-37;43,18;-33,18",
                         "-13,-68;47,-68;47,-30;-13,-30"
                     ]
@@ -208,7 +216,7 @@
                     "height": "19",
                     "type": "box",
                     "polygons": [
-                        "-400,24;400,24;400,50;-400,50"
+                        "-400,24;400,24;400,59;-400,59"
                     ]
                 },
                 {
@@ -263,7 +271,7 @@
                     "height": "33",
                     "type": "box",
                     "polygons": [
-                        "-300,-49; 300,-49; 300,-24; -300,-24"
+                        "-300,-49; 300,-49; 300,-19; -300,-19"
                     ]
                 },
                 {
diff --git a/resources/data/printer_gantries/prusa3d_coreone_gantry.stl b/resources/data/printer_gantries/prusa3d_coreone_gantry.stl
index e8e0294078..cde5efc1bd 100644
Binary files a/resources/data/printer_gantries/prusa3d_coreone_gantry.stl and b/resources/data/printer_gantries/prusa3d_coreone_gantry.stl differ
diff --git a/resources/data/printer_gantries/prusa3d_xl_gantry.stl b/resources/data/printer_gantries/prusa3d_xl_gantry.stl
index 0fb888d4e5..f08c16e139 100644
Binary files a/resources/data/printer_gantries/prusa3d_xl_gantry.stl and b/resources/data/printer_gantries/prusa3d_xl_gantry.stl differ
diff --git a/src/libseqarrange/src/seq_preprocess.cpp b/src/libseqarrange/src/seq_preprocess.cpp
index a1e117d224..ab1318dc77 100644
--- a/src/libseqarrange/src/seq_preprocess.cpp
+++ b/src/libseqarrange/src/seq_preprocess.cpp
@@ -470,6 +470,15 @@ Slic3r::Polygon scaleUp_PolygonForSlicer(coord_t scale_factor, const Polygon &po
 }
 
 
+Slic3r::Polygon truncate_PolygonAsSeenBySequentialSolver(coord_t scale_factor, const Slic3r::Polygon &polygon)
+{
+    Slic3r::Polygon scale_down_polygon = scaleDown_PolygonForSequentialSolver(scale_factor, polygon);
+    Slic3r::Polygon scale_up_polygon = scaleUp_PolygonForSlicer(scale_factor, scale_down_polygon);
+
+    return scale_up_polygon;
+}
+
+
 void ground_PolygonByBoundingBox(Slic3r::Polygon &polygon)
 {    
     BoundingBox polygon_box = get_extents(polygon);
@@ -610,9 +619,30 @@ void decimate_PolygonForSequentialSolver(double                 DP_tolerance,
 	    {
 		if (extra_safety)
 		{
-		    grow_PolygonForContainedness(center_x, center_y, decimated_polygon);
+		    Slic3r::Polygon prefinal_polygon = decimated_polygon;
+
+		    while (true)
+		    {
+			grow_PolygonForContainedness(center_x, center_y, decimated_polygon);
+			Slic3r::Polygon truncated_polygon = truncate_PolygonAsSeenBySequentialSolver(SEQ_SLICER_SCALE_FACTOR, decimated_polygon);
+
+			bool trunc_contains = true;		    
+			for (unsigned int i = 0; i < prefinal_polygon.points.size(); ++i)
+			{
+			    if (!Slic3r::contains(truncated_polygon, prefinal_polygon.points[i], false))
+			    {
+				trunc_contains = false;
+				break;
+			    }
+			}
+
+			if (trunc_contains)
+			{
+			    return;
+			}
+		    }
 		}
-		break;
+		return;
 	    }
 	}
     }
diff --git a/src/libseqarrange/src/seq_preprocess.hpp b/src/libseqarrange/src/seq_preprocess.hpp
index 6cd68641bd..ccf14242fb 100644
--- a/src/libseqarrange/src/seq_preprocess.hpp
+++ b/src/libseqarrange/src/seq_preprocess.hpp
@@ -106,7 +106,9 @@ Slic3r::Polygon scaleUp_PolygonForSlicer(const Slic3r::Polygon &polygon);
 Slic3r::Polygon scaleUp_PolygonForSlicer(coord_t scale_factor, const Slic3r::Polygon &polygon);
     
 Slic3r::Polygon scaleUp_PolygonForSlicer(const Slic3r::Polygon &polygon, double x_pos, double y_pos);
-Slic3r::Polygon scaleUp_PolygonForSlicer(coord_t scale_factor, const Slic3r::Polygon &polygon, double x_pos, double y_pos);    
+Slic3r::Polygon scaleUp_PolygonForSlicer(coord_t scale_factor, const Slic3r::Polygon &polygon, double x_pos, double y_pos);
+
+Slic3r::Polygon truncate_PolygonAsSeenBySequentialSolver(coord_t scale_factor, const Slic3r::Polygon &polygon);
     
 void ground_PolygonByBoundingBox(Slic3r::Polygon &polygon);
 void ground_PolygonByFirstPoint(Slic3r::Polygon &polygon);