diff --git a/render.py b/render.py
index ee139bc..6fb3ed5 100755
--- a/render.py
+++ b/render.py
@@ -4,24 +4,33 @@ import os
 import sys
 import shutil
 import subprocess
+from time import *
 
-def render(machine):
+def render(machine, parts):
     stl_dir = machine + os.sep + "stls"
     render_dir = machine + os.sep + "render"
 
     if os.path.isdir(render_dir):
-        shutil.rmtree(render_dir)   #clear out any dross
-    os.makedirs(render_dir)
+        if not parts:
+            shutil.rmtree(render_dir)   #if doing them all clear the directory first
+            sleep(0.1)
+            os.makedirs(render_dir)
+    else:
+        os.makedirs(render_dir)
+
     #
     # List of individual part files
     #
-    stls = [i[:-4] for i in os.listdir(stl_dir) if i[-4:] == ".stl"]
-    #
-    # Add the multipart files
-    #
-    for i in  os.listdir(stl_dir + os.sep + "printed"):
-        if not i[:-4] in stls:
-            stls.append("printed" + os.sep + i[:-4])
+    if parts:
+        stls = [i[:-4] for i in parts]
+    else:
+        stls = [i[:-4] for i in os.listdir(stl_dir) if i[-4:] == ".stl"]
+        #
+        # Add the multipart files
+        #
+        for i in  os.listdir(stl_dir + os.sep + "printed"):
+            if i[-4:] == ".stl" and not i[:-4] in stls:
+                stls.append("printed" + os.sep + i[:-4])
 
     for i in stls:
         command = 'blender -b  utils' + os.sep + 'render.blend -P utils' + os.sep + 'viz.py -- ' + \
@@ -31,7 +40,7 @@ def render(machine):
 
 if __name__ == '__main__':
     if len(sys.argv) > 1:
-        render(sys.argv[1])
+        render(sys.argv[1], sys.argv[2:])
     else:
-        print "usage: render [mendel|sturdy|your_machine]"
+        print "usage: render dibond|mendel|sturdy|your_machine, [part.stl ...]"
         sys.exit(1)