Aurora A3 Fan Duct (Nozzle) - New & Improved!

thingiverse

This is a custom Fan Duct/Nozzle designed specifically for the hot-end of an Aurora A3 Prusa I3 printer. NOTE: This nozzle is as large as it can possibly be made and does come very close to the hot-end and bed adjustment knobs when homed. Please exercise extreme caution when using this duct, especially with CraftWare Slicer, that it does not run into the bed adjustment knobs. I assume no responsibility and you have been warned. After testing a previously modified Nozzle, Prusa I3 Fan Duct for Aurora A3 Printer, which failed miserably to improve my prints, I set out to design a new one and came up with this custom nozzle. You can see the improvements in print quality that this new nozzle makes in the photos above. The torus is now almost perfectly round and void of all but the smallest overhang blobs. Only the underside of the torus at the top shows any malformations from spanning that gap, and these were all printed without supports on the torus. While different Slicers can improve print quality (CraftWare did a better job on this than Cura), both showed marked improvement in quality. Your mileage may vary. I believe issues with the old design were inadequate air flow and direction: The Fan has an opening of 135 sq mm, but it is choked down to ~40 sq mm before entering the loop. Significant air flow and pressure are lost at that point. At the exit holes, the air flow direction is not well defined while the total opening size is ~50 sq mm. This increase in size further slows down air flow. My new design maintains an opening of over 120 sq mm at the entrance to the loop, maintaining significant air flow and pressure all around the loop. The vents are aimed directly at the nozzle's tip through a 7mm long, 7mm wide, and 2-1mm long channel. The narrowing channel (from 2mm to 1mm) and its length, I believe accelerate the air flow and accurately direct it with equal volume all around the hot end nozzle. Indeed, when the nozzle fan kicks in after the first layer, the hot end temperature immediately drops by 5C (but reheats again after a few seconds). Immediately cooling and solidifying the PLA appears to keep the overhangs from curling and forming blobs as well as improve the finish of the part overall. Again, your mileage may vary. Print Settings: Printer Brand: RepRap Printer: AG Aurora A3 Prusa I3 Rafts: No Supports: No Resolution: .2mm Infill: 15% Notes: You do not need any support for this print. Required ones are already set inside the torus for the top. Most of the sides are only .5mm thick to gain maximum internal volume. Because of this, much of this object is a single wall print. If you have problems with gaps in your walls, bottoms or tops, you may wish to increase your Filament Flow to 105%-110% for this print. Infill is optional due to the very little Infill in this object. How I Designed This Made with Sketchup I have provided the Sketchup file for this object in case anyone is interested in adapting this for their printer. Enjoy!