diff --git a/cura/BuildVolume.py b/cura/BuildVolume.py
index e9b90e3a61..143b2fefbb 100644
--- a/cura/BuildVolume.py
+++ b/cura/BuildVolume.py
@@ -1,11 +1,9 @@
 # Copyright (c) 2015 Ultimaker B.V.
 # Cura is released under the terms of the AGPLv3 or higher.
 
-from UM.View.Renderer import Renderer
 from UM.Scene.SceneNode import SceneNode
 from UM.Application import Application
 from UM.Resources import Resources
-from UM.Mesh.MeshData import MeshData
 from UM.Mesh.MeshBuilder import MeshBuilder
 from UM.Math.Vector import Vector
 from UM.Math.Color import Color
diff --git a/cura/ConvexHullNode.py b/cura/ConvexHullNode.py
index 7f0f87ade5..b99e80fcff 100644
--- a/cura/ConvexHullNode.py
+++ b/cura/ConvexHullNode.py
@@ -9,8 +9,6 @@ from UM.Mesh.MeshBuilder import MeshBuilder #To create a mesh to display the con
 
 from UM.View.GL.OpenGL import OpenGL
 
-import numpy
-
 class ConvexHullNode(SceneNode):
     def __init__(self, node, hull, parent = None):
         super().__init__(parent)
diff --git a/cura/CuraActions.py b/cura/CuraActions.py
index e585b261d0..36bf32fdd7 100644
--- a/cura/CuraActions.py
+++ b/cura/CuraActions.py
@@ -1,11 +1,9 @@
-from PyQt5.QtCore import QObject, pyqtSignal, pyqtSlot, pyqtProperty, QUrl
+from PyQt5.QtCore import QObject, pyqtSlot, pyqtProperty, QUrl
 from PyQt5.QtGui import QDesktopServices
 
 from UM.Event import CallFunctionEvent
 from UM.Application import Application
 
-import webbrowser
-
 class CuraActions(QObject):
     def __init__(self, parent = None):
         super().__init__(parent)
diff --git a/cura/CuraApplication.py b/cura/CuraApplication.py
index 1b41cdda2f..0f35a3dd98 100644
--- a/cura/CuraApplication.py
+++ b/cura/CuraApplication.py
@@ -1,8 +1,6 @@
 # Copyright (c) 2015 Ultimaker B.V.
 # Cura is released under the terms of the AGPLv3 or higher.
 
-import platform
-
 from UM.Qt.QtApplication import QtApplication
 from UM.Scene.SceneNode import SceneNode
 from UM.Scene.Camera import Camera
@@ -49,7 +47,6 @@ from PyQt5.QtQml import qmlRegisterUncreatableType
 
 import platform
 import sys
-import os
 import os.path
 import numpy
 import copy
diff --git a/cura/PlatformPhysics.py b/cura/PlatformPhysics.py
index df841bd71d..f660d68f34 100644
--- a/cura/PlatformPhysics.py
+++ b/cura/PlatformPhysics.py
@@ -19,8 +19,6 @@ from . import PlatformPhysicsOperation
 from . import ConvexHullJob
 from . import ZOffsetDecorator
 
-import time
-import threading
 import copy
 
 class PlatformPhysics:
@@ -132,7 +130,7 @@ class PlatformPhysics:
                         else:
                             overlap = node.callDecoration("getConvexHull").intersectsPolygon(other_node.callDecoration("getConvexHull"))
                     except:
-                        overlap = None #It can sometimes occur that the caclulated convex hull has no size, in which case there is no overlap.
+                        overlap = None #It can sometimes occur that the calculated convex hull has no size, in which case there is no overlap.
 
                     if overlap is None:
                         continue
diff --git a/cura/PrintInformation.py b/cura/PrintInformation.py
index a3a2bb2948..73dde53437 100644
--- a/cura/PrintInformation.py
+++ b/cura/PrintInformation.py
@@ -10,18 +10,18 @@ from UM.Qt.Duration import Duration
 
 import math
 
-##  A class for processing and calculating minimum, currrent and maximum print time.
+##  A class for processing and calculating minimum, current and maximum print time.
 #
 #   This class contains all the logic relating to calculation and slicing for the
 #   time/quality slider concept. It is a rather tricky combination of event handling
 #   and state management. The logic behind this is as follows:
 #
-#   - A scene change or settting change event happens.
+#   - A scene change or setting change event happens.
 #        We track what the source was of the change, either a scene change, a setting change, an active machine change or something else.
 #   - This triggers a new slice with the current settings - this is the "current settings pass".
 #   - When the slice is done, we update the current print time and material amount.
 #   - If the source of the slice was not a Setting change, we start the second slice pass, the "low quality settings pass". Otherwise we stop here.
-#   - When that is done, we update the minimum print time and start the final slcice pass, the "high quality settings pass".
+#   - When that is done, we update the minimum print time and start the final slice pass, the "high quality settings pass".
 #   - When the high quality pass is done, we update the maximum print time.
 #
 class PrintInformation(QObject):
diff --git a/cura_app.py b/cura_app.py
index e19147c5e5..853edabd5e 100755
--- a/cura_app.py
+++ b/cura_app.py
@@ -4,11 +4,10 @@
 # Cura is released under the terms of the AGPLv3 or higher.
 
 import sys
-import os
 
-def exceptHook(type, value, traceback):
+def exceptHook(hook_type, value, traceback):
     import cura.CrashHandler
-    cura.CrashHandler.show(type, value, traceback)
+    cura.CrashHandler.show(hook_type, value, traceback)
 
 sys.excepthook = exceptHook
 
@@ -16,7 +15,7 @@ sys.excepthook = exceptHook
 # is a race condition between Arcus and PyQt. Importing Arcus
 # first seems to prevent Sip from going into a state where it
 # tries to create PyQt objects on a non-main thread.
-import Arcus
+import Arcus #@UnusedImport
 import cura.CuraApplication
 
 if sys.platform == "win32" and hasattr(sys, "frozen"):
diff --git a/plugins/3MFReader/ThreeMFReader.py b/plugins/3MFReader/ThreeMFReader.py
index ee86f720d8..fc748f61db 100644
--- a/plugins/3MFReader/ThreeMFReader.py
+++ b/plugins/3MFReader/ThreeMFReader.py
@@ -12,10 +12,7 @@ from UM.Math.Quaternion import Quaternion
 
 from UM.Job import Job
 
-import os
-import struct
 import math
-from os import listdir
 import zipfile
 
 import xml.etree.ElementTree as ET
@@ -32,8 +29,6 @@ class ThreeMFReader(MeshReader):
         }
 
     def read(self, file_name):
-        result = None
-
         result = SceneNode()
         # The base object of 3mf is a zipped archive.
         archive = zipfile.ZipFile(file_name, "r")
@@ -46,16 +41,16 @@ class ThreeMFReader(MeshReader):
                 Logger.log("w", "No objects found in 3MF file %s, either the file is corrupt or you are using an outdated format", file_name)
                 return None
 
-            for object in objects:
+            for entry in objects:
                 mesh = MeshData()
                 node = SceneNode()
                 vertex_list = []
-                #for vertex in object.mesh.vertices.vertex:
-                for vertex in object.findall(".//3mf:vertex", self._namespaces):
+                #for vertex in entry.mesh.vertices.vertex:
+                for vertex in entry.findall(".//3mf:vertex", self._namespaces):
                     vertex_list.append([vertex.get("x"), vertex.get("y"), vertex.get("z")])
                     Job.yieldThread()
 
-                triangles = object.findall(".//3mf:triangle", self._namespaces)
+                triangles = entry.findall(".//3mf:triangle", self._namespaces)
 
                 mesh.reserveFaceCount(len(triangles))
 
@@ -72,7 +67,7 @@ class ThreeMFReader(MeshReader):
                 node.setMeshData(mesh)
                 node.setSelectable(True)
 
-                transformation = root.findall("./3mf:build/3mf:item[@objectid='{0}']".format(object.get("id")), self._namespaces)
+                transformation = root.findall("./3mf:build/3mf:item[@objectid='{0}']".format(entry.get("id")), self._namespaces)
                 if transformation:
                     transformation = transformation[0]
 
diff --git a/plugins/LayerView/LayerView.py b/plugins/LayerView/LayerView.py
index 9f65a8e783..eb9c3bc91e 100644
--- a/plugins/LayerView/LayerView.py
+++ b/plugins/LayerView/LayerView.py
@@ -2,7 +2,6 @@
 # Cura is released under the terms of the AGPLv3 or higher.
 
 from UM.View.View import View
-from UM.View.Renderer import Renderer
 from UM.Scene.Iterator.DepthFirstIterator import DepthFirstIterator
 from UM.Resources import Resources
 from UM.Event import Event, KeyEvent
@@ -11,7 +10,6 @@ from UM.Scene.Selection import Selection
 from UM.Math.Color import Color
 from UM.Mesh.MeshData import MeshData
 from UM.Job import Job
-from UM.Message import Message
 
 from UM.View.RenderBatch import RenderBatch
 from UM.View.GL.OpenGL import OpenGL
@@ -23,7 +21,6 @@ from PyQt5.QtWidgets import QApplication
 
 from . import LayerViewProxy
 
-import time
 from UM.i18n import i18nCatalog
 catalog = i18nCatalog("cura")
 
@@ -139,7 +136,7 @@ class LayerView(View):
 
     def calculateMaxLayers(self):
         scene = self.getController().getScene()
-        renderer = self.getRenderer()
+        renderer = self.getRenderer() # TODO: Unused variable
         self._activity = True
 
         self._old_max_layers = self._max_layers
diff --git a/plugins/LegacyProfileReader/LegacyProfileReader.py b/plugins/LegacyProfileReader/LegacyProfileReader.py
index 661646bf64..3daf360ee6 100644
--- a/plugins/LegacyProfileReader/LegacyProfileReader.py
+++ b/plugins/LegacyProfileReader/LegacyProfileReader.py
@@ -51,10 +51,10 @@ class LegacyProfileReader(ProfileReader):
     #   \return A set of local variables, one for each setting in the legacy
     #   profile.
     def prepareLocals(self, config_parser, config_section, defaults):
-        locals = defaults.copy() #Don't edit the original!
+        copied_locals = defaults.copy() #Don't edit the original!
         for option in config_parser.options(config_section):
-            locals[option] = config_parser.get(config_section, option)
-        return locals
+            copied_locals[option] = config_parser.get(config_section, option)
+        return copied_locals
 
     ##  Reads a legacy Cura profile from a file and returns it.
     #
diff --git a/plugins/PerObjectSettingsTool/PerObjectSettingsTool.py b/plugins/PerObjectSettingsTool/PerObjectSettingsTool.py
index 70b3d8bbe8..dc65725839 100644
--- a/plugins/PerObjectSettingsTool/PerObjectSettingsTool.py
+++ b/plugins/PerObjectSettingsTool/PerObjectSettingsTool.py
@@ -4,7 +4,6 @@
 from UM.Tool import Tool
 from UM.Scene.Selection import Selection
 from UM.Application import Application
-from UM.Qt.ListModel import ListModel
 from UM.Preferences import Preferences
 
 from . import PerObjectSettingsModel
diff --git a/plugins/RemovableDriveOutputDevice/LinuxRemovableDrivePlugin.py b/plugins/RemovableDriveOutputDevice/LinuxRemovableDrivePlugin.py
index ce948c472b..46e3dafb71 100644
--- a/plugins/RemovableDriveOutputDevice/LinuxRemovableDrivePlugin.py
+++ b/plugins/RemovableDriveOutputDevice/LinuxRemovableDrivePlugin.py
@@ -4,6 +4,8 @@
 
 from . import RemovableDrivePlugin
 
+from UM.Logger import Logger
+
 import glob
 import os
 import subprocess
@@ -33,6 +35,7 @@ class LinuxRemovableDrivePlugin(RemovableDrivePlugin.RemovableDrivePlugin):
     def performEjectDevice(self, device):
         p = subprocess.Popen(["umount", device.getId()], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
         output = p.communicate()
+        Logger.log("d", "umount returned: %s.", repr(output))
 
         return_code = p.wait()
         if return_code != 0:
diff --git a/plugins/RemovableDriveOutputDevice/OSXRemovableDrivePlugin.py b/plugins/RemovableDriveOutputDevice/OSXRemovableDrivePlugin.py
index e02e0d65b6..4b65ce024d 100644
--- a/plugins/RemovableDriveOutputDevice/OSXRemovableDrivePlugin.py
+++ b/plugins/RemovableDriveOutputDevice/OSXRemovableDrivePlugin.py
@@ -4,10 +4,9 @@
 
 from . import RemovableDrivePlugin
 
-import threading
+from UM.Logger import Logger
 
 import subprocess
-import time
 import os
 
 import plistlib
@@ -44,8 +43,9 @@ class OSXRemovableDrivePlugin(RemovableDrivePlugin.RemovableDrivePlugin):
         return drives
 
     def performEjectDevice(self, device):
-        p = subprocess.Popen(["diskutil", "eject", path], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        p = subprocess.Popen(["diskutil", "eject", device.getId()], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
         output = p.communicate()
+        Logger.log("d", "umount returned: %s.", repr(output))
 
         return_code = p.wait()
         if return_code != 0:
diff --git a/plugins/SliceInfoPlugin/SliceInfo.py b/plugins/SliceInfoPlugin/SliceInfo.py
index 78d0c7cec0..ed018f7d89 100644
--- a/plugins/SliceInfoPlugin/SliceInfo.py
+++ b/plugins/SliceInfoPlugin/SliceInfo.py
@@ -66,7 +66,7 @@ class SliceInfo(Extension):
                 break
 
 
-        profile_values = settings.getChangedSettings()
+        profile_values = settings.getChangedSettings() # TODO: Unused variable
 
         # Get total material used (in mm^3)
         print_information = Application.getInstance().getPrintInformation()
diff --git a/plugins/USBPrinting/PrinterConnection.py b/plugins/USBPrinting/PrinterConnection.py
index c19603c945..d28324b71c 100644
--- a/plugins/USBPrinting/PrinterConnection.py
+++ b/plugins/USBPrinting/PrinterConnection.py
@@ -8,7 +8,6 @@ import time
 import queue
 import re
 import functools
-import os
 import os.path
 
 from UM.Application import Application
diff --git a/plugins/USBPrinting/USBPrinterManager.py b/plugins/USBPrinting/USBPrinterManager.py
index fcb61c3365..fbcd6201d7 100644
--- a/plugins/USBPrinting/USBPrinterManager.py
+++ b/plugins/USBPrinting/USBPrinterManager.py
@@ -19,7 +19,6 @@ import threading
 import platform
 import glob
 import time
-import os
 import os.path
 import sys
 from UM.Extension import Extension
@@ -60,7 +59,7 @@ class USBPrinterManager(QObject, SignalEmitter, OutputDevicePlugin, Extension):
     @pyqtProperty(float, notify = progressChanged)
     def progress(self):
         progress = 0
-        for name, connection in self._printer_connections.items():
+        for printer_name, connection in self._printer_connections.items():
             progress += connection.progress
 
         return progress / len(self._printer_connections)