I've been printing a lot of whistles lately (popular with kids), and comparing prints on my Felix vs. the school Printrbot metal. I noticed that the Printrbot (with a fully encircling fan shroud) does a much better job of bridging the top of the whistle than my Felix does. I'm wondering if the difference is in the fan or in the slicing (slic3r for the printrbot, sfact for the Felix; Felix default settings also probably different [faster?] than Printrbot settings). I noticed that the fan blowing on the hot end tip is quite far away on the Felix, and was wondering if that had something to do with it. Also recalled that Felix didn't do so well with bridging on the Make 3D Printer shootout.
So does anyone have insights to share on getting better bridging performance?