diff --git a/octoprint_gcode_ripper/G_Code_Rip.py b/octoprint_gcode_ripper/G_Code_Rip.py
index 8adcaf0..5563518 100644
--- a/octoprint_gcode_ripper/G_Code_Rip.py
+++ b/octoprint_gcode_ripper/G_Code_Rip.py
@@ -1613,8 +1613,8 @@ def generategcode(self,side,z_safe=.5,
                 D2 = line[2][2]-line[1][2]
                 D012 = sqrt((D0+0j).real**2+(D1+0j).real**2+(D2+0j).real**2)
                 
-                coordA=[ line[1][0], line[1][1], line[1][2] ]
-                coordB=[ line[2][0], line[2][1], line[2][2] ]
+                coordA=[ line[1][0], line[1][1], line[1][2] ] #this is previous
+                coordB=[ line[2][0], line[2][1], line[2][2] ] #this is current
                 if Wrap == "Y2A" or Wrap == "Y2B":
                     #if line[1][1].imag == 0:
                     if (not isinstance(line[1][1], complex)):
@@ -1630,6 +1630,7 @@ def generategcode(self,side,z_safe=.5,
                             coordB[1]=sign*degrees(2*asin(line[2][1]/(2*Rstock)))
                         else:
                             coordB[1]=sign*degrees(line[2][1]/Rstock)
+                    
                 elif Wrap == "X2B" or Wrap == "X2A":
                     #if line[1][0].imag == 0:
                     if (not isinstance(line[1][0], complex)):
diff --git a/octoprint_gcode_ripper/__init__.py b/octoprint_gcode_ripper/__init__.py
index 7281d8d..b40bc97 100644
--- a/octoprint_gcode_ripper/__init__.py
+++ b/octoprint_gcode_ripper/__init__.py
@@ -34,6 +34,7 @@ def __init__(self):
         self.min_seg = 1.0
         self.datafolder = None
         self.template_name = None
+        self.zrelative = False
         #self.watched_path = self._settings.global_get_basefolder("watched")
     ##~~ SettingsPlugin mixin
     def initialize(self):
@@ -77,7 +78,7 @@ def _get_templates(self):
     def generate_name(self):
         #abbreviate origin
         ori = self.origin[0].upper()
-        wrapdiam = self.start_diameter + 2*(self.currentZ)
+        wrapdiam = self.calc_diameter()
         output_name = f"D{int(wrapdiam)}_R{int(self.rotation)}_Ori{ori}_"
         return output_name
     
@@ -87,7 +88,7 @@ def generate_gcode(self):
         gcr.Read_G_Code("{}/{}".format(self._settings.getBaseFolder("uploads"), gcode_file), XYarc2line=True, units="mm")
         self.mapping = "Y2A"
         polar = False
-        wrapdiam = self.start_diameter + 2*(self.currentZ)
+        wrapdiam = self.calc_diameter()
         output_name = self.generate_name()
         output_path = output_name+self.template_name
         path_on_disk = "{}/{}".format(self._settings.getBaseFolder("watched"), output_path)
@@ -145,6 +146,12 @@ def generate_gcode(self):
                                           FSCALE="None"):
                 newfile.write(f"\n{line}")
     
+    def calc_diameter(self):
+        if self.zrelative:
+            return self.start_diameter + 2*(self.currentZ)
+        else:
+            return self.start_diameter
+        
     def update_image(self):
         self._file_manager.set_additional_metadata("local",self.selected_file,"bgs_imgurl",self.selected_image,overwrite=True)
 
@@ -169,6 +176,7 @@ def on_api_command(self, command, data):
             self.mapping = "Y2A"
             self.split_moves = bool(data["split_moves"])
             self.min_seg = float(data["min_seg"])
+            self.zrelative = bool(data["zrelative"])
             self.generate_gcode()
 
         if command == "editmeta":
diff --git a/octoprint_gcode_ripper/static/js/gcode_ripper.js b/octoprint_gcode_ripper/static/js/gcode_ripper.js
index d3cdf40..b43d14a 100644
--- a/octoprint_gcode_ripper/static/js/gcode_ripper.js
+++ b/octoprint_gcode_ripper/static/js/gcode_ripper.js
@@ -23,6 +23,7 @@ $(function() {
         self.newimage = ko.observable("");
         self.thumbnail_url = ko.observable('/static/img/tentacle-20x20.png');
         self.zPos = ko.observable("");
+        self.zrelative = ko.observable(0);
         
 
         tab = document.getElementById("tab_plugin_gcode_ripper_link");
@@ -129,6 +130,7 @@ $(function() {
                 split_moves: self.split_moves(),
                 min_seg: self.min_seg_length(),
                 origin: self.origin(),
+                zrelative: self.zrelative()
             };
 
             OctoPrint.simpleApiCommand("gcode_ripper", "write_gcode", data)
@@ -197,7 +199,12 @@ $(function() {
         self.onDataUpdaterPluginMessage = function(plugin, data) {
             if (plugin == 'gcode_ripper' && data.type == 'grbl_state') {
                 self.zPos(Number.parseFloat(data.z).toFixed(2));
-                self.calc_diameter = (Number.parseFloat(self.diameter()) + (self.zPos()*2));
+
+                if (self.zrelative) {
+                    self.calc_diameter = (Number.parseFloat(self.diameter()) + (self.zPos()*2));
+                } else {
+                    self.calc_diameter = self.diameter;
+                }
                 //console.log(newDiam);
             }
         }        
diff --git a/octoprint_gcode_ripper/templates/gcode_ripper_tab.jinja2 b/octoprint_gcode_ripper/templates/gcode_ripper_tab.jinja2
index 0a247b0..84cdddf 100644
--- a/octoprint_gcode_ripper/templates/gcode_ripper_tab.jinja2
+++ b/octoprint_gcode_ripper/templates/gcode_ripper_tab.jinja2
@@ -18,6 +18,13 @@
                     <input id="scale_factor_input" type="number" value="1" step="any" class="span4" data-bind="value: scaleFactor">
             </div>
 
+            <div class="row">
+                <label for="zrelative">Reference Diam.
+                <i class="icon icon-info-sign" title="When checked, the input diameter is a reference diameter at Z=0. The current work position Z value is added to this value to calculate the diameter." data-toggle="tooltip"></i>
+                <input id="zrelative" type="checkbox" unchecked data-bind="checked: zrelative">
+                </label>
+            </div>
+
             <div class="row" style="padding-left: 20px; padding-bottom: 10px;">
                 <div class="span12">
                     <label for="gcode_file_select">Select GCode File:</label>