Streamliner i3 Fan duct: Low profile, lightweight, effective cooling fan duct.

thingiverse

I didn't need a fan duct badly, but after taking out my original plate steel duct I was surprised by how much weight it had. I decided to kill two birds with one stone and create a new fan duct that would be more effective and lighter in weight than the original. This modification is a direct swap for the original, and will use the same fan even if you're short on cable length. I've also included a 0.4mm spacer in case you want to drop it down a bit. The stock should have a couple of millimeters clearance from the printbed and because the duct is directed downwards slightly this is fine. Results are remarkably good. See the test print comparison. The rubbish one is the normal vent. In fact, these results were so good I'm wondering if my cooling fan was misbehaving in the rubbish print (same gcode for both prints). The existing screws may be a tight fit. You may have to run a 2.5mm drill bit through the holes first. I decided I'd rather have them too tight than too loose.