Do you cool your Prusa's filament immediately after extrusion?

[Chachin]

Greetings,

Are many/any of you guys using a fan to cool the filament immediately exiting the extruder of your Prusa i3 or i3v? If so, what have your prints gained from this? Is a fan only/mostly applicable to PLA?

I ask because it looks like Slic3r supports the use of such a fan, so I am tempted to rig one up and try it.

I would appreciate any feedback.

Chachin..

PS: Merry Christmas!

[printbus]

They're mainly used with PLA. ABS prints best when the entire print is maintained at a warm temperature to minimize warping due to the ABS shrinking as it cools. PLA retains heat for a very long time. Especially on small prints, this can lead to subsequent layers printing on layers that are still somewhat soft, and print quality suffers.

Slicers allow you to adjust the amount of print cooling airflow for different layers. Depending on what you're using for a print surface and the adhesion it has, you can keep airflow off or low for the first few layers to help with bed adhesion but then crank up the cooling once you're off the bed a ways.

EDIT: Once you see the difference a good print cooling fan can make in PLA print quality, you'll almost always print with it on. Walls will be straighter; details will be finer, corners will be sharper.

[kd7eir]

I agree with everything printbus said, plus -
One of the biggest improvements my cooling fan has made has been with bridging. Prior to the print cooling fan bridging was hit and miss, now I don't even worry about bridging at all - it just works.

[Chachin]

Thanks for the feedback guys. It sounds like I should follow through with it then, especially since all my printing right now is done in PLA.

Is there a particular (quality) fan you guys would recommend for this purpose?

Chachin..

[clough42]

Fans work wonders with PLA. For ABS, you have to be very careful. They can help with overhangs and bridging, and they're great if you have a tall part with very small layers. For these parts, the hot end just hovers over the tower, radiating heat into it and the plastic doesn't really solidify, causing a "Dr. Seuss" effect. But air blowing on ABS prints can also cause serious problems with warping and bed adhesion. This is why slicers usually allow you to keep the fan off for the first few layers, but even this is sometimes not enough.

A fan is pure magic for ABS bridging, though. Here's an example of 200mm bridges in ABS on a MakerFarm printer. The filament sags at first, then pulls taut as the fan cools and shrinks it.

[kd7eir]

Fans work wonders with PLA. For ABS, you have to be very careful. They can help with overhangs and bridging, and they're great if you have a tall part with very small layers. For these parts, the hot end just hovers over the tower, radiating heat into it and the plastic doesn't really solidify, causing a "Dr. Seuss" effect. But air blowing on ABS prints can also cause serious problems with warping and bed adhesion. This is why slicers usually allow you to keep the fan off for the first few layers, but even this is sometimes not enough.

A fan is pure magic for ABS bridging, though. Here's an example of 200mm bridges in ABS on a MakerFarm printer. The filament sags at first, then pulls taut as the fan cools and shrinks it.

Since I started using your Improved Hexagon Cooling System and your Print Cooling Fan System for MakerFarm Prusa i3 and i3v, my prints have taken on a whole new dimension of excellence. Thank you for all your work in making our hobby better.

[Roxy]

Wow! That is magic. I'm not sure I believe this!

[clough42]

Wow! That is magic. I'm not sure I believe this!

If I had faked it, the video quality would have been better.

[hernejj]

With PLA, in my experience, overhangs tend to curl up when not properly cooled. Over time, this up-curl looks quite nasty and even interferes with the nozzle as the curl sits higher than the rest of the print.

If you want an example, try printing this: http://www.thingiverse.com/thing:28405

Anyways, a good string cooling fan has solved this issue for me.