Spare parts - fan shroud  

Eminent Member

I have finished assembling my MK3S+ and will begin printing some spare parts.  I can't seem to find this question answered anywhere, although I'm sure it has been asked before.  For the Fan Shroud, I assume this should be printed in ABS, Nylon, or something with higher heat tolerance than PETG?  There is no note about it on the parts download page, which just references printing parts in PETG.


Thanks in advance,


Stock Prusa MK3S+ built from kit on 12/2020
OctoPrint, typically print from a drybox, no enclosure yet
Printing proudly since 2011...
Posted : 28/12/2020 1:48 pm
Kevin Reid
Trusted Member

Quick answer — you're correct. If the fan shroud is printed in PLA or PETG it will soften and sag in use. Prusa has made fan shrouds in ABS and now ASA, and I've heard of people making them in polycarbonate.

Posted : 28/12/2020 3:28 pm
Matto liked
Eminent Member

I've never used ASA.  Might be time for a new filament! 🙂

Stock Prusa MK3S+ built from kit on 12/2020
OctoPrint, typically print from a drybox, no enclosure yet
Printing proudly since 2011...
Posted : 28/12/2020 5:09 pm

I don't print ASA or ABS, for health reasons, 

the Blob of Doom, that I had yesterday managed to fill the fan shroud vents with plastic lava... 

So I re printed a replacement in PETG without any fan shroud on my printer... the resulting fan shroud  turned out nicely... and will las me some time, as I only print PETG< PLA and TPU. 

I do have some  Mk3S+ ASA Fan Shrouds on order from Prusa, but it's anybody's guess when they will arrive given the Covid restrictions and the  developing Brexit situation... 
when they arrive I will consider printing the Mk3S+ extruder parts and seeing how they work... 

Regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 28/12/2020 5:24 pm
Matto liked
Eminent Member


I am using PLA fan shrouds that I annealed. Heat treated PLA parts can retain function a bit above 100 Deg. C. In use for over 18 months with no sagging. I am starting to print with the Prusament PC Blend now so I can report back if I find problems with that but so far (6 hours or so printing) no sagging or damage. I tend to print more PET-G than PLA so the shrouds have been mainly exposed to PET-G printing temperatures. I think that annealed PLA is a viable material for a fan shroud. But as I said, it is another technique to get our head around and there is always plenty to learn when 3D printing without adding more techniques.





Posted : 28/12/2020 7:17 pm
Matto liked
Active Member

My original PETG fan shrouds didn't fare well at all with my MK3S.  I wound up buying a printed part from Etsy since I don't have an enclosure and don't print ABS/ASA.  In hindsight I should have held off, the MKS3+ upgrade kit includes the fan shroud in ASA.

Posted : 30/12/2020 5:52 am
Estimable Member

I have used one printed in PETG that worked fine with printing PETG.

I printed it in PETG as I didn't have any other filament than PLA and PETG at the time. And wanted to try an modified fan shroud.

The original fan shroud that came with the MK3s is still just fine. That one is ABS or ASA.


In an other post here someone mentioned Colorfabb HT as an alternative. That is what I use now.

For me it prints just as easy on the textured sheet and PETG, but it can handle much higher temps.

Today I did a other print with the Colorfabb with the default prusa setting for this filament. (nozzle @275c and bed at 110c part cooling fan off)

Even after 2 hours there is no sagging at all this close to the hot hotend. Also heating the hotend to change the filament and forgetting about it didn't damage it so far.

Posted : 30/12/2020 7:23 pm

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