diff --git a/src/main/java/org/micromanager/lightsheetmanager/gui/tabs/navigation/NavigationPanel.java b/src/main/java/org/micromanager/lightsheetmanager/gui/tabs/navigation/NavigationPanel.java
index 70c755a..491dcc4 100644
--- a/src/main/java/org/micromanager/lightsheetmanager/gui/tabs/navigation/NavigationPanel.java
+++ b/src/main/java/org/micromanager/lightsheetmanager/gui/tabs/navigation/NavigationPanel.java
@@ -8,7 +8,7 @@
 import org.micromanager.Studio;
 import org.micromanager.lightsheetmanager.model.LightSheetManagerModel;
 
-import javax.swing.*;
+import javax.swing.JLabel;
 import javax.swing.border.TitledBorder;
 import java.util.ArrayList;
 import java.util.Comparator;
@@ -229,7 +229,7 @@ public void createUserInterface() {
     private void createEventHandlers() {
 
         btnRefreshPanel_.registerListener(e -> {
-            System.out.println("refresh pressed");
+            //System.out.println("refresh pressed");
             removeAll();
             createUserInterface();
             createEventHandlers();
@@ -248,7 +248,7 @@ private void createEventHandlers() {
             } else {
                 positionUpdater_.stopPolling();
             }
-            System.out.println("poll positions isSelected: " + cbxPollPositions_.isSelected());
+            //System.out.println("poll positions isSelected: " + cbxPollPositions_.isSelected());
         });
 
     }
@@ -274,7 +274,6 @@ private boolean containsDigit(final String str) {
      */
     public void updatePositions() {
         //System.out.println("isEDT: " + SwingUtilities.isEventDispatchThread());
-        //System.out.println("updating!");
         for (ControlPanel panel : controlPanels_) {
             panel.updatePosition();
         }
@@ -296,10 +295,11 @@ public PositionUpdater getPositionUpdater() {
         return positionUpdater_;
     }
 
-    public void haltAllDevices() {
-        //System.out.println("Halt pressed!");
+    /**
+     * Halt all 2D and 1D stage devices.
+     */
+    private void haltAllDevices() {
         for (ControlPanel controlPanel : controlPanels_) {
-            // only try to stop XY and 1D stages
             DeviceType deviceType = controlPanel.getDeviceType();
             if (deviceType == DeviceType.XYStageDevice || deviceType == DeviceType.StageDevice) {
                 controlPanel.stop();
diff --git a/src/main/java/org/micromanager/lightsheetmanager/model/DeviceManager.java b/src/main/java/org/micromanager/lightsheetmanager/model/DeviceManager.java
index 2139efb..add3c3f 100644
--- a/src/main/java/org/micromanager/lightsheetmanager/model/DeviceManager.java
+++ b/src/main/java/org/micromanager/lightsheetmanager/model/DeviceManager.java
@@ -45,7 +45,7 @@ public class DeviceManager {
     private Map<String, DeviceBase> deviceMap_;
     private Map<String, DeviceBase> devicesAdded_;
 
-    private LightSheetManagerModel model_;
+    private final LightSheetManagerModel model_;
 
     private static String deviceAdapterName_;
     public static final String LSM_DEVICE_LIBRARY = "LightSheetManager";
diff --git a/src/main/java/org/micromanager/lightsheetmanager/model/acquisitions/AcquisitionEngineSCAPE.java b/src/main/java/org/micromanager/lightsheetmanager/model/acquisitions/AcquisitionEngineSCAPE.java
index c342e69..855dd03 100644
--- a/src/main/java/org/micromanager/lightsheetmanager/model/acquisitions/AcquisitionEngineSCAPE.java
+++ b/src/main/java/org/micromanager/lightsheetmanager/model/acquisitions/AcquisitionEngineSCAPE.java
@@ -56,10 +56,19 @@ public AcquisitionEngineSCAPE(final LightSheetManagerModel model) {
     @Override
     boolean setup() {
 
+//        // check pixel size
+//        if (core_.getPixelSizeUm() < 1e-6) {
+//            studio_.logs().showError(
+//                    "Pixel size not set, navigate to \"Devices > Pixel Size Calibration...\" to set the value.");
+//            return false;
+//        }
+
         // this is needed for LSMAcquisitionEvents to work with multiple positions
         if (core_.getFocusDevice().isEmpty()
                 && acqSettings_.isUsingMultiplePositions()) {
-            studio_.logs().showError("The default focus device \"Core-Focus\" needs to be set to use multiple positions.");
+            studio_.logs().showError(
+                    "The default focus device \"Core-Focus\" needs to be set to use multiple positions.");
+            return false;
         }
 
         // make sure that there are positions in the PositionList