What's all this hoopla about fans?

[Khalid Khattak]

Again a writeup that will help us all and also the new comers like me.... As i didn't use FAN so far as i am now printing with ABS and enjoying ABS printing and do not want to go to PLA ( never have a single print experience)... I like the writeup, i like " I prefer to position the fans on the build platform rather than the printing head. This gives me more direct cooling to all parts of the print and removes mass from the print head. It also allows me to use several smaller fans distributed around the part rather than one big fan blowing a lot of unused air"
Very helpful, Sir.

[BenTheRighteous]

Joseph, are you using your layer fan with ABS? That will absolutely degrade print quality. Layer fan is for PLA only.

There is no way to disable the PEEK fan. You always want it to run.

[Jimustanguitar]

Some do have great success with layer fans on ABS, I know I do. There's no black and white rule about when to use cooling fans, everybody's machine is just a slight bit different, different elevations and humidity, different filament, and we're all printing different parts (ok, the exact same Yoda head). Just be cautious with it, sometimes it makes sense and other times it does not. Learning the difference, and why is the trick.

[mhackney]

I agree in principle. But the way to look at it is not "a fan" but rather as "air flow". Once you start thinking in that way, understanding cooling takes a big leap forward.

[Tonkabot]

I recently printed some very small objects in ABS and had to turn the print speed down to 25% and turn on the layer fan - it would have been just a pile of goo without it.

So, yes using Layer cooling with ABS is absolutely required if you have really small stuff - and of course all the other times Mhackney called out...

I am curious about the liquid cooled heads - they are just cooling the where the PEEK and PEEK fan would be, right? It seems like it should be a pretty good way to go, although it might be heavier than the PEEK fan.

[EDIT] I think I replied to someone that said you NEVER should use a layer fan with ABS, and by the time my post went up their post seemed to be gone! I didn't realize we could delete posts, but I see the button there now...

[geneb]

Another way to do that without running the fan is to print multiples of the same part. It gives more time for the ABS to cool.

g.

[RocketMagnet]

I use the layer fan now and again with ABS... mainly bridging and small areas and occasionally on the next fill layer after infill especially with low infill %ages... try printing a thin vertical column without any cooling and see how for you get .
So using cooling on ABS is situation dependant though where possible try and avoid it at low layer heights as the standard blower will really drop your bed temp...

When I started I even disconnected the layer fan initially as I don't use PLA anymore except in the odd application... I've since learned the error of my ways
and been totally sold on the benefits of selective cooling with ABS. With the right cooling it's amazing how you much can improve certain prints... and how far you can bridge