we highly recommend slicing these bells with an OLD version of cura (e.g. 13.04) so you can use the 'joris' function for perfectly smooth results. The newer versions of Cura don't do a good job here (yet)print a set of these fast lightweight bells and hang them in your tree, or string them along a ribbon to hang in the window.single wall will print fine (and fast)who dares to fork this and add lights ?