diff --git a/solid/objects.py b/solid/objects.py
index 5149f243..52e55722 100644
--- a/solid/objects.py
+++ b/solid/objects.py
@@ -168,8 +168,8 @@ class union(OpenSCADObject):
     def __init__(self):
         OpenSCADObject.__init__(self, 'union', {})
 
-    def __add__(self, x):
-        return self.add(x)
+    #def __add__(self, x):
+        #return self.add(x)
 
 
 class intersection(OpenSCADObject):
@@ -180,8 +180,8 @@ class intersection(OpenSCADObject):
     def __init__(self):
         OpenSCADObject.__init__(self, 'intersection', {})
 
-    def __mul__(self, x):
-        return self.add(x)
+    #def __mul__(self, x):
+        #return self.add(x)
 
 
 class difference(OpenSCADObject):
@@ -191,8 +191,8 @@ class difference(OpenSCADObject):
     def __init__(self):
         OpenSCADObject.__init__(self, 'difference', {})
 
-    def __sub__(self,x):
-        return self.add(x)
+    #def __sub__(self,x):
+        #return self.add(x)
 
 
 class hole(OpenSCADObject):
@@ -408,9 +408,9 @@ class rotate_extrude(OpenSCADObject):
     :type segments: int
 
     '''
-    def __init__(self, convexity=None, segments=None):
+    def __init__(self, angle=None, convexity=None, segments=None):
         OpenSCADObject.__init__(self, 'rotate_extrude',
-                                {'convexity': convexity, 'segments': segments})
+                                {'angle':angle, 'convexity': convexity, 'segments': segments})
 
 
 class dxf_linear_extrude(OpenSCADObject):
diff --git a/solid/solidpython.py b/solid/solidpython.py
index 1a0e89ef..6ae69129 100755
--- a/solid/solidpython.py
+++ b/solid/solidpython.py
@@ -247,15 +247,15 @@ def new_openscad_class_str(class_name, args=[], kwargs=[], include_file_path=Non
     args_pairs = ''
 
     for arg in args:
-        args_str += ', ' + arg
-        args_pairs += "'%(arg)s':%(arg)s, " % vars()
+        args_str += ', _' + arg
+        args_pairs += "'%(arg)s':_%(arg)s, " % vars()
 
     # kwargs have a default value defined in their SCAD versions.  We don't
     # care what that default value will be (SCAD will take care of that), just
     # that one is defined.
     for kwarg in kwargs:
         args_str += ', %(kwarg)s=None' % vars()
-        args_pairs += "'%(kwarg)s':%(kwarg)s, " % vars()
+        args_pairs += "'%(kwarg)s':_%(kwarg)s, " % vars()
 
     if include_file_path:
         # include_file_path may include backslashes on Windows; escape them