Fan queston for you gurus

So, I am embarking on a design project and had some things I want to clear up. I had some questions about the cooling fan (not the heat sink fan, the extrusion cooling fan, starboard side, 24v). Just trying to wrap my head around it. I see so many different fan shroud designs. Some seem to aim right at the nozzle tip best they can, others seem to be aimed down at where the part would be. Just exactly what is it supposed to be cooling? Are we wanting it to cool the filament as its being extruded out of the nozzle, or is it supposed to be cooling the part already printed?

I print primarily in ABS so I very rarely use the cooling fan. I see lots of references to it with PLA so I presume its pretty critical for that material.

Anyone care to share the logic surrounding this fan appendage?

Hi Wolfie,

I would say, point the fan shroud so that it cools the material just as is extruded form the nozzle and touches the layer beneath. The fan should be able to aid with bridging, which is printing over open space, as well as printing overhangs and fine details, for which you want to cool the material quickly to avoid any droopiness. For PLA I do like to keep my fan blowing high, and ABS just a tad for detail’s sake.

:bulb: A note, if you are working on this already, you may want to look into adding fans blowing from left and right. This will aid in effectiveness for PLA prints and bridging with all materials.

I already have the mounting plate from my prior hexagon project that has a left side mounting place, so yes, both port and starboard fans are a possibility.

Wolfie
Can you share what the hexagon mounting plate looks like for a double side cooling fan. Are you using a standard Hexagon hot end or the one that ships with the TAZ 5.

Full load of images from the project are in this album:
http://www.ipernity.com/doc/wolfie/album/773974

Here is one of the images of the plate:

Yes, I am using Lulz’ version of the Hex hot end. The reprap one is distinctly longer.

Full details of the build is in this thread here on the forums:
https://forum.lulzbot.com/t/30-40mm-heat-sink-fan-for-taz-hexagon/1630/1