diff --git a/octoprint_slicer/static/js/octoprint_slicer.min.js b/octoprint_slicer/static/js/octoprint_slicer.min.js
index 18ba7a7..7eff874 100644
--- a/octoprint_slicer/static/js/octoprint_slicer.min.js
+++ b/octoprint_slicer/static/js/octoprint_slicer.min.js
@@ -32754,7 +32754,7 @@ function SlicerViewModel(parameters) {
         }
     };
 
-    self.sliceRequestData = function (slicingVM, group) {
+    self.sliceRequestData = function (slicingVM, groupCenter) {
         var destinationFilename = slicingVM._sanitize(slicingVM.destinationFilename());
 
         var destinationExtensions = slicingVM.data[slicingVM.slicer()] && slicingVM.data[slicingVM.slicer()].extensions && slicingVM.data[slicingVM.slicer()].extensions.destination ? slicingVM.data[slicingVM.slicer()].extensions.destination : ["???"];
@@ -32763,9 +32763,8 @@ function SlicerViewModel(parameters) {
         })) {
             destinationFilename = destinationFilename + "." + destinationExtensions[0];
         }
-        var groupCenter = new Vector3(0, 0, 0);
-        if (group) {
-            groupCenter = new Box3().setFromObject(group).getCenter();
+        if (!groupCenter) {
+            groupCenter = new Vector3(0, 0, 0);
         }
         var data = {
             command: "slice",
@@ -32813,11 +32812,14 @@ function SlicerViewModel(parameters) {
 
             var form = new FormData();
             var group = new Group();
+            var groupBox3 = new Box3();
             forEach$1(self.stlViewPort.models(), function (model) {
                 group.add(model.clone(true));
+                groupBox3.expandByPoint(model.userData.box3FromObject().min);
+                groupBox3.expandByPoint(model.userData.box3FromObject().max);
             });
 
-            sliceRequestData = self.sliceRequestData(self.slicingViewModel, group);
+            sliceRequestData = self.sliceRequestData(self.slicingViewModel, groupBox3.getCenter());
 
             var tempFilename = self.tempSTLFilename();
             form.append("file", self.blobFromModel(group), tempFilename);
diff --git a/src/slicer.js b/src/slicer.js
index ebde77c..4e04694 100644
--- a/src/slicer.js
+++ b/src/slicer.js
@@ -329,7 +329,7 @@ function SlicerViewModel(parameters) {
         }
     }
 
-    self.sliceRequestData = function(slicingVM, group) {
+    self.sliceRequestData = function(slicingVM, groupCenter) {
         var destinationFilename = slicingVM._sanitize(slicingVM.destinationFilename());
 
         var destinationExtensions = slicingVM.data[slicingVM.slicer()] && slicingVM.data[slicingVM.slicer()].extensions && slicingVM.data[slicingVM.slicer()].extensions.destination
@@ -340,9 +340,8 @@ function SlicerViewModel(parameters) {
         })) {
             destinationFilename = destinationFilename + "." + destinationExtensions[0];
         }
-        var groupCenter = new THREE.Vector3(0,0,0);
-        if (group) {
-            groupCenter = new THREE.Box3().setFromObject(group).getCenter();
+        if (!groupCenter) {
+            groupCenter = new THREE.Vector3(0,0,0);
         }
         var data = {
             command: "slice",
@@ -391,11 +390,14 @@ function SlicerViewModel(parameters) {
 
             var form = new FormData();
             var group = new THREE.Group();
+            let groupBox3 = new THREE.Box3();
             forEach(self.stlViewPort.models(), function (model) {
                 group.add(model.clone(true));
+                groupBox3.expandByPoint(model.userData.box3FromObject().min);
+                groupBox3.expandByPoint(model.userData.box3FromObject().max);
             });
 
-            sliceRequestData = self.sliceRequestData(self.slicingViewModel, group);
+            sliceRequestData = self.sliceRequestData(self.slicingViewModel, groupBox3.getCenter());
 
             var tempFilename = self.tempSTLFilename();
             form.append("file", self.blobFromModel(group), tempFilename);