diff --git a/gviz.py b/gviz.py
index 131ab33..24148ac 100755
--- a/gviz.py
+++ b/gviz.py
@@ -1,9 +1,9 @@
 import wx,time
 
 class window(wx.Frame):
-    def __init__(self,f,size=(600,600),bedsize=(200,200),center=(100,100),grid=(10,50),extrusion_width=0.5):
+    def __init__(self,f,size=(600,600),build_dimensions=[200,200,100,0,0,0],grid=(10,50),extrusion_width=0.5):
         wx.Frame.__init__(self,None,title="Layer view (Use shift+mousewheel to switch layers)",size=(size[0],size[1]))
-        self.p=gviz(self,size=size,bedsize=bedsize,center=center,grid=grid,extrusion_width=extrusion_width)
+        self.p=gviz(self,size=size,build_dimensions=build_dimensions,grid=grid,extrusion_width=extrusion_width)
         s=time.time()
         for i in f:
             self.p.addgcode(i)
@@ -53,11 +53,10 @@ class window(wx.Frame):
             elif z < 0: self.p.zoom(event.GetX(),event.GetY(),1/1.2)
         
 class gviz(wx.Panel):
-    def __init__(self,parent,size=(200,200),bedsize=(200,200),center=(100,100),grid=(10,50),extrusion_width=0.5):
+    def __init__(self,parent,size=(200,200),build_dimensions=[200,200,100,0,0,0],grid=(10,50),extrusion_width=0.5):
         wx.Panel.__init__(self,parent,-1,size=(size[0],size[1]))
         self.size=size
-        self.bedsize=bedsize
-        self.center=center
+        self.build_dimensions=build_dimensions
         self.grid=grid
         self.lastpos=[0,0,0,0,0,0,0]
         self.hilightpos=self.lastpos[:]
@@ -70,7 +69,7 @@ class gviz(wx.Panel):
         self.layers=[]
         self.layerindex=0
         self.filament_width=extrusion_width # set it to 0 to disable scaling lines with zoom
-        self.scale=[min(float(size[0])/bedsize[0],float(size[1])/bedsize[1])]*2
+        self.scale=[min(float(size[0])/build_dimensions[0],float(size[1])/build_dimensions[1])]*2
         penwidth = max(1.0,self.filament_width*((self.scale[0]+self.scale[1])/2.0))
         self.translate=[0.0,0.0]
         self.mainpen=wx.Pen(wx.Colour(0,0,0),penwidth)
@@ -136,10 +135,10 @@ class gviz(wx.Panel):
         dc.SetPen(wx.Pen(wx.Colour(180,180,150)))
         for grid_unit in self.grid:
             if grid_unit > 0:
-                for x in xrange(int(self.bedsize[0]/grid_unit)+1):
-                    dc.DrawLine(self.translate[0]+x*self.scale[0]*grid_unit,self.translate[1],self.translate[0]+x*self.scale[0]*grid_unit,self.translate[1]+self.scale[1]*self.bedsize[1])
-                for y in xrange(int(self.bedsize[1]/grid_unit)+1):
-                    dc.DrawLine(self.translate[0],self.translate[1]+y*self.scale[1]*grid_unit,self.translate[0]+self.scale[0]*self.bedsize[0],self.translate[1]+y*self.scale[1]*grid_unit)
+                for x in xrange(int(self.build_dimensions[0]/grid_unit)+1):
+                    dc.DrawLine(self.translate[0]+x*self.scale[0]*grid_unit,self.translate[1],self.translate[0]+x*self.scale[0]*grid_unit,self.translate[1]+self.scale[1]*self.build_dimensions[1])
+                for y in xrange(int(self.build_dimensions[1]/grid_unit)+1):
+                    dc.DrawLine(self.translate[0],self.translate[1]+y*self.scale[1]*grid_unit,self.translate[0]+self.scale[0]*self.build_dimensions[0],self.translate[1]+y*self.scale[1]*grid_unit)
             dc.SetPen(wx.Pen(wx.Colour(0,0,0)))
         if not self.showall:
             self.size = self.GetSize()
@@ -237,9 +236,9 @@ class gviz(wx.Panel):
             return target
         
         def _y(y):
-            return self.bedsize[1]-(y+(self.bedsize[0]/2-self.center[0]))
+            return self.build_dimensions[1]-(y-self.build_dimensions[4])
         def _x(x):
-            return x+(self.bedsize[0]/2-self.center[0])
+            return x-self.build_dimensions[3]
         
         start_pos = self.hilightpos[:] if hilight else self.lastpos[:]
         
diff --git a/pronterface.py b/pronterface.py
index 741b397..0901ce5 100755
--- a/pronterface.py
+++ b/pronterface.py
@@ -57,10 +57,8 @@ class PronterWindow(wx.Frame,pronsole.pronsole):
         self.settings.last_file_path = ""
         self.settings.last_temperature = 0.0
         self.settings.last_bed_temperature = 0.0
-        self.settings.bed_size_x = 200.
-        self.settings.bed_size_y = 200.
-        self.settings.bed_center_x = 100.
-        self.settings.bed_center_y = 100.
+        #default build dimensions are 200x200x100 with 0,0,0 in the corner of the bed
+        self.settings.build_dimensions = '200x200x100+0+0+0'
         self.settings.preview_grid_step1 = 10.
         self.settings.preview_grid_step2 = 50.
         self.settings.preview_extrusion_width = 0.5
@@ -86,7 +84,11 @@ class PronterWindow(wx.Frame,pronsole.pronsole):
         ]
         self.custombuttons=[]
         self.btndict={}
+        print self.settings.build_dimensions
         self.parse_cmdline(sys.argv[1:])
+        print self.settings.build_dimensions
+        self.build_dimensions_list = self.get_build_dimensions(self.settings.build_dimensions)
+        print self.build_dimensions_list
         customdict={}
         try:
             execfile("custombtn.txt",customdict)
@@ -611,14 +613,12 @@ class PronterWindow(wx.Frame,pronsole.pronsole):
         self.zfeedc.SetForegroundColour("black")
         # lls.Add((10,0),pos=(0,11),span=(1,1))
         self.gviz=gviz.gviz(self.panel,(300,300),
-            bedsize=(self.settings.bed_size_x,self.settings.bed_size_y),
-            center=(self.settings.bed_center_x,self.settings.bed_center_y),
+            build_dimensions=self.build_dimensions_list,
             grid=(self.settings.preview_grid_step1,self.settings.preview_grid_step2),
             extrusion_width=self.settings.preview_extrusion_width)
         self.gviz.showall=1
         self.gwindow=gviz.window([],
-            bedsize=(self.settings.bed_size_x,self.settings.bed_size_y),
-            center=(self.settings.bed_center_x,self.settings.bed_center_y),
+            build_dimensions=self.build_dimensions_list,
             grid=(self.settings.preview_grid_step1,self.settings.preview_grid_step2),
             extrusion_width=self.settings.preview_extrusion_width)
         self.gviz.Bind(wx.EVT_LEFT_DOWN,self.showwin)
@@ -1462,6 +1462,35 @@ class PronterWindow(wx.Frame,pronsole.pronsole):
                 wx.CallAfter(self.pausebtn.SetLabel, _("Pause"))
                 wx.CallAfter(self.printbtn.SetLabel, _("Print"))
                 self.paused=0
+    
+    def get_build_dimensions(self,bdim):
+        import re
+        # a string containing up to six numbers delimited by almost anything
+        # first 0-3 numbers specify the build volume, no sign, always positive
+        # remaining 0-3 numbers specify the coordinates of the "southwest" corner of the build platform
+        # "XXX,YYY"
+        # "XXXxYYY+xxx-yyy"
+        # "XXX,YYY,ZZZ+xxx+yyy-zzz"
+        # etc
+        bdl = re.match(
+        "[^\d+-]*(\d+)?" + # X build size
+        "[^\d+-]*(\d+)?" + # Y build size
+        "[^\d+-]*(\d+)?" + # Z build size
+        "[^\d+-]*([+-]\d+)?" + # X corner coordinate
+        "[^\d+-]*([+-]\d+)?" + # Y corner coordinate
+        "[^\d+-]*([+-]\d+)?"   # Z corner coordinate
+        ,bdim).groups()
+        print bdl
+        bdl_float = [
+        200.0 if bdl[0]==None else float(bdl[0]),
+        200.0 if bdl[1]==None else float(bdl[1]),
+        100.0 if bdl[2]==None else float(bdl[2]),
+        0.0 if bdl[3]==None else float(bdl[3]),
+        0.0 if bdl[4]==None else float(bdl[4]),
+        0.0 if bdl[5]==None else float(bdl[5]),
+        ]
+        return bdl_float
+
             
 class macroed(wx.Dialog):
     """Really simple editor to edit macro definitions"""