diff --git a/ag.cc b/ag.cc
index c23d72f..20f0d6a 100644
--- a/ag.cc
+++ b/ag.cc
@@ -62,6 +62,8 @@ namespace ag
             { "type", type },
             { "clearWorld", clearWorld },
 
+            { "_createAMotor", _createAMotor },
+
             /* managed object functions */
             { "createBox", createBox },
             { "createBoxStatic", createBoxStatic },
@@ -277,6 +279,8 @@ namespace ag
         lua_setfield(L, -2, "setBounce");
         lua_pushcfunction(L, joint::setAMotorAxis);
         lua_setfield(L, -2, "setAxis");
+        lua_pushcfunction(L, joint::setAMotorNumAxes);
+        lua_setfield(L, -2, "setNumAxes");
     }
 
     int _createAMotor(lua_State * L)
@@ -286,9 +290,12 @@ namespace ag
         {
             Engine::Object * o1 = object::getObject(L, 1);
             Engine::Object * o2 = object::getObject(L, 2);
-            if (o1 != NULL && o2 != NULL)
+            /* it is ok if o1 or o2 are NULL, this means that the motor
+             * is connected to the global environment */
+            int jid = g_engine->addAMotor(o1, o2);
+            if (jid != 0)
             {
-                lua_pushinteger(L, g_engine->addAMotor(o1, o2));
+                createLuaAMotor(L, jid);
                 return 1;
             }
         }
@@ -1291,6 +1298,22 @@ namespace ag
             return 0;
         }
 
+        int setAMotorNumAxes(lua_State * L)
+        {
+            int argc = lua_gettop(L);
+            if (argc == 2 && lua_istable(L, 1) && lua_isnumber(L, 2))
+            {
+                lua_getfield(L, 1, "id");
+                if (lua_isnumber(L, -1))
+                {
+                    int jid = lua_tointeger(L, -1);
+                    g_engine->setAMotorNumAxes(jid, lua_tointeger(L, 2));
+                }
+                lua_pop(L, 1);
+            }
+            return 0;
+        }
+
         int setAMotorLoStop(lua_State * L)
         {
             int argc = lua_gettop(L);
diff --git a/ag.h b/ag.h
index b8a6d15..c159022 100644
--- a/ag.h
+++ b/ag.h
@@ -92,6 +92,7 @@ namespace ag
     namespace joint
     {
         int setAMotorAxis(lua_State * L);
+        int setAMotorNumAxes(lua_State * L);
         int setAMotorLoStop(lua_State * L);
         int setAMotorHiStop(lua_State * L);
         int setAMotorVel(lua_State * L);
diff --git a/ag.lua b/ag.lua
index 845570d..150f831 100644
--- a/ag.lua
+++ b/ag.lua
@@ -43,7 +43,7 @@ ag.createAMotor = function(obj1, obj2, axis0, axis1, axis2)
                 amotor:setBounce(v)
             end
         end
-        amotor:setAxis(rel, x, y, z)
+        amotor:setAxis(anum, rel, x, y, z)
     end
 
     local o1 = obj1
@@ -62,23 +62,26 @@ ag.createAMotor = function(obj1, obj2, axis0, axis1, axis2)
         end
     end
 
-    local amotor = ag._createAMotor(obj1, obj2)
+    local amotor = ag._createAMotor(o1, o2)
 
-    if (axis0 ~= nil) then
-        setAMotorAxis(amotor, 0, axis0)
-        num_axes = 1
-        if (axis1 ~= nil) then
-            setAMotorAxis(amotor, 1, axis1)
+    if (amotor ~= nil) then
+        if (axis0 ~= nil) then
+            setAMotorAxis(amotor, 0, axis0)
             num_axes = 1
-            if (axis2 ~= nil) then
-                setAMotorAxis(amotor, 2, axis2)
-                num_axes = 2
+            if (axis1 ~= nil) then
+                setAMotorAxis(amotor, 1, axis1)
+                num_axes = 1
+                if (axis2 ~= nil) then
+                    setAMotorAxis(amotor, 2, axis2)
+                    num_axes = 2
+                end
             end
         end
+        amotor:setNumAxes(num_axes)
+    else
+        ag.println("Error creating AMotor!")
     end
 
-    amotor:setNumAxes(num_axes)
-
     return amotor
 end
 
diff --git a/tests/managed_objects.lua b/tests/managed_objects.lua
index d586780..8173738 100644
--- a/tests/managed_objects.lua
+++ b/tests/managed_objects.lua
@@ -37,5 +37,11 @@ function key_down_event(key)
         init_obj(sphere)
     elseif (key == "q") then
         ag.exit()
+    elseif (key == "r") then
+        -- creating a rotating cube
+        local box = ag.createBox(1, 1, 1)
+        init_obj(box)
+        ag.createAMotor(0, box,
+            { x = 0, y = 0, z = 1, vel = 10, fmax = 10 })
     end
 end