diff --git a/xs/src/libslic3r/Model.cpp b/xs/src/libslic3r/Model.cpp
index 73f524f63..ba232ad3f 100644
--- a/xs/src/libslic3r/Model.cpp
+++ b/xs/src/libslic3r/Model.cpp
@@ -609,7 +609,7 @@ TriangleMesh
 ModelObject::mesh() const
 {
     TriangleMesh mesh;
-    
+
     for (ModelInstancePtrs::const_iterator i = this->instances.begin(); i != this->instances.end(); ++i) {
         TransformationMatrix instance_trafo = (*i)->get_trafo_matrix();
         for (ModelVolumePtrs::const_iterator v = this->volumes.begin(); v != this->volumes.end(); ++v) {
@@ -731,6 +731,20 @@ ModelObject::translate(coordf_t x, coordf_t y, coordf_t z)
 {
     for (ModelVolumePtrs::const_iterator v = this->volumes.begin(); v != this->volumes.end(); ++v) {
         (*v)->trafo.translate(x, y, z);
+        printf("Translate obj trafo: %.1f, %.1f, %.1f, %.1f; %.1f, %.1f, %.1f, %.1f; %.1f, %.1f, %.1f, %.1f\n", 
+            ((*v)->trafo.m11),
+            ((*v)->trafo.m12),
+            ((*v)->trafo.m13),
+            ((*v)->trafo.m14),
+            ((*v)->trafo.m21),
+            ((*v)->trafo.m22),
+            ((*v)->trafo.m23),
+            ((*v)->trafo.m24),
+            ((*v)->trafo.m31),
+            ((*v)->trafo.m32),
+            ((*v)->trafo.m33),
+            ((*v)->trafo.m34)
+            );
     }
     if (this->_bounding_box_valid) this->_bounding_box.translate(x, y, z);
 }
@@ -747,6 +761,20 @@ ModelObject::scale(const Pointf3 &versor)
     if (versor.x == 1 && versor.y == 1 && versor.z == 1) return;
     for (ModelVolumePtrs::const_iterator v = this->volumes.begin(); v != this->volumes.end(); ++v) {
         (*v)->trafo.scale(versor.x, versor.y, versor.z);
+        printf("Scale obj trafo: %.1f, %.1f, %.1f, %.1f; %.1f, %.1f, %.1f, %.1f; %.1f, %.1f, %.1f, %.1f\n", 
+            ((*v)->trafo.m11),
+            ((*v)->trafo.m12),
+            ((*v)->trafo.m13),
+            ((*v)->trafo.m14),
+            ((*v)->trafo.m21),
+            ((*v)->trafo.m22),
+            ((*v)->trafo.m23),
+            ((*v)->trafo.m24),
+            ((*v)->trafo.m31),
+            ((*v)->trafo.m32),
+            ((*v)->trafo.m33),
+            ((*v)->trafo.m34)
+            );
     }
     
     // reset origin translation since it doesn't make sense anymore
@@ -774,6 +802,20 @@ ModelObject::rotate(float angle, const Axis &axis)
     if (angle == 0) return;
     for (ModelVolumePtrs::const_iterator v = this->volumes.begin(); v != this->volumes.end(); ++v) {
         (*v)->trafo.rotate(angle, axis);
+        printf("Rotation obj trafo: %.1f, %.1f, %.1f, %.1f; %.1f, %.1f, %.1f, %.1f; %.1f, %.1f, %.1f, %.1f\n", 
+            ((*v)->trafo.m11),
+            ((*v)->trafo.m12),
+            ((*v)->trafo.m13),
+            ((*v)->trafo.m14),
+            ((*v)->trafo.m21),
+            ((*v)->trafo.m22),
+            ((*v)->trafo.m23),
+            ((*v)->trafo.m24),
+            ((*v)->trafo.m31),
+            ((*v)->trafo.m32),
+            ((*v)->trafo.m33),
+            ((*v)->trafo.m34)
+            );
     }
     this->origin_translation = Pointf3(0,0,0);
     this->invalidate_bounding_box();
@@ -784,6 +826,20 @@ ModelObject::mirror(const Axis &axis)
 {
     for (ModelVolumePtrs::const_iterator v = this->volumes.begin(); v != this->volumes.end(); ++v) {
         (*v)->trafo.mirror(axis);
+        printf("Mirror obj trafo: %.1f, %.1f, %.1f, %.1f; %.1f, %.1f, %.1f, %.1f; %.1f, %.1f, %.1f, %.1f\n", 
+            ((*v)->trafo.m11),
+            ((*v)->trafo.m12),
+            ((*v)->trafo.m13),
+            ((*v)->trafo.m14),
+            ((*v)->trafo.m21),
+            ((*v)->trafo.m22),
+            ((*v)->trafo.m23),
+            ((*v)->trafo.m24),
+            ((*v)->trafo.m31),
+            ((*v)->trafo.m32),
+            ((*v)->trafo.m33),
+            ((*v)->trafo.m34)
+            );
     }
     this->origin_translation = Pointf3(0,0,0);
     this->invalidate_bounding_box();