diff --git a/cura/Machines/MachineTools.py b/cura/Machines/MachineTools.py
new file mode 100644
index 0000000000..91daa2490b
--- /dev/null
+++ b/cura/Machines/MachineTools.py
@@ -0,0 +1,25 @@
+from UM.Util import parseBool
+
+
+#
+# Gets the machine definition ID that can be used to search for Quality containers that are suitable for the given
+# machine. The rule is as follows:
+#   1. By default, the machine definition ID for quality container search will be "fdmprinter", which is the generic
+#      machine.
+#   2. If a machine has its own machine quality (with "has_machine_quality = True"), we should use the given machine's
+#      own machine definition ID for quality search.
+#      Example: for an Ultimaker 3, the definition ID should be "ultimaker3".
+#   3. When condition (2) is met, AND the machine has "quality_definition" defined in its definition file, then the
+#      definition ID specified in "quality_definition" should be used.
+#      Example: for an Ultimaker 3 Extended, it has "quality_definition = ultimaker3". This means Ultimaker 3 Extended
+#               shares the same set of qualities profiles as Ultimaker 3.
+#
+def getMachineDefinitionIDForQualitySearch(machine: "GlobalStack", default_definition_id: str = "fdmprinter") -> str:
+    machine_definition_id = default_definition_id
+    if parseBool(machine.getMetaDataEntry("has_machine_quality", False)):
+        # Only use the machine's own quality definition ID if this machine has machine quality.
+        machine_definition_id = machine.getMetaDataEntry("quality_definition")
+        if machine_definition_id is None:
+            machine_definition_id = machine.definition.getId()
+
+    return machine_definition_id
diff --git a/cura/Machines/QualityManager.py b/cura/Machines/QualityManager.py
index ad4fa6fc8f..cb723f41d0 100644
--- a/cura/Machines/QualityManager.py
+++ b/cura/Machines/QualityManager.py
@@ -1,14 +1,14 @@
 from typing import Optional
 
-from PyQt5.Qt import pyqtSignal, QObject
+from PyQt5.Qt import QObject
 
 from UM.Application import Application
 from UM.Logger import Logger
-from UM.Settings.InstanceContainer import InstanceContainer
 from UM.Util import parseBool
 
 from cura.Machines.ContainerGroup import ContainerGroup
 from cura.Machines.ContainerNode import ContainerNode
+from cura.Machines.MachineTools import getMachineDefinitionIDForQualitySearch
 
 
 #
@@ -114,12 +114,12 @@ class QualityManager(QObject):
 
     def __init__(self, container_registry, parent = None):
         super().__init__(parent)
-
-        self._material_manager = Application.getInstance()._material_manager
-
+        self._application = Application.getInstance()
+        self._material_manager = self._application._material_manager
         self._container_registry = container_registry
-        self._empty_quality_container = self._container_registry.findInstanceContainers(id = "empty_quality")[0]
-        #self._empty_quality_changes_container = self._container_registry.findInstanceContainers(id = "empty_quality_changes")[0]
+
+        self._empty_quality_container = self._application.empty_quality_container
+        self._empty_quality_changes_container = self._application.empty_quality_changes_container
 
         self._machine_variant_material_quality_type_to_quality_dict = {}  # for quality lookup
         self._machine_quality_type_to_quality_changes_dict = {}  # for quality_changes lookup
@@ -229,12 +229,8 @@ class QualityManager(QObject):
     # Returns a dict of "custom profile name" -> QualityChangesGroup
     def getQualityChangesGroups(self, machine: "GlobalStack") -> dict:
         # TODO: How to make this simpler?
-        # Get machine definition ID
-        machine_definition_id = self._default_machine_definition_id
-        if parseBool(machine.getMetaDataEntry("has_machine_quality", False)):
-            machine_definition_id = machine.getMetaDataEntry("quality_definition")
-            if machine_definition_id is None:
-                machine_definition_id = machine.definition.getId()
+        # Get machine definition ID for quality search
+        machine_definition_id = getMachineDefinitionIDForQualitySearch(machine)
 
         machine_node = self._machine_quality_type_to_quality_changes_dict.get(machine_definition_id)
         if not machine_node:
@@ -257,12 +253,8 @@ class QualityManager(QObject):
 
     def getQualityGroups(self, machine: "GlobalStack") -> dict:
         # TODO: How to make this simpler, including the fall backs.
-        # Get machine definition ID
-        machine_definition_id = self._default_machine_definition_id
-        if parseBool(machine.getMetaDataEntry("has_machine_quality", False)):
-            machine_definition_id = machine.getMetaDataEntry("quality_definition")
-            if machine_definition_id is None:
-                machine_definition_id = machine.definition.getId()
+        # Get machine definition ID for quality search
+        machine_definition_id = getMachineDefinitionIDForQualitySearch(machine)
 
         # To find the quality container for the GlobalStack, check in the following fall-back manner:
         #   (1) the machine-specific node
diff --git a/cura/Settings/CuraStackBuilder.py b/cura/Settings/CuraStackBuilder.py
index 365658ee48..19a5caacb8 100644
--- a/cura/Settings/CuraStackBuilder.py
+++ b/cura/Settings/CuraStackBuilder.py
@@ -1,4 +1,4 @@
-# Copyright (c) 2017 Ultimaker B.V.
+# Copyright (c) 2018 Ultimaker B.V.
 # Cura is released under the terms of the LGPLv3 or higher.
 
 from UM.Logger import Logger
@@ -206,9 +206,8 @@ class CuraStackBuilder:
 
         return container
 
-
     @classmethod
-    def createDefinitionChangesContainer(cls, container_stack, container_name, container_index = None):
+    def createDefinitionChangesContainer(cls, container_stack, container_name):
         from cura.CuraApplication import CuraApplication
 
         unique_container_name = ContainerRegistry.getInstance().uniqueName(container_name)