Spare parts - fan shroud  

RE: Spare parts - fan shroud

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.

RE: Spare parts - fan shroud

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

RE: Spare parts - fan shroud

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

RE: Spare parts - fan shroud

Matt,

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.

Cheers

Neil

RE: Spare parts - fan shroud

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.

RE: Spare parts - fan shroud

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.

RE: Spare parts - fan shroud

Sorry to revive an old thread, but is there a good reason to use ASA vs. ABS for the fan shroud? Fumes are not a factor for me since I have a vented enclosure.

RE: Spare parts - fan shroud

@gglockner

I ended up printing some spares in PETG and ASA, although I am still using the one that came with the printer.  I can't imagine for this part why it would matter at all as long as it doesn't melt when you print with it.  

 -Matt

RE: Spare parts - fan shroud

I used a remixed fan shroud as an excuse to try out the PC Blend filament.

RE: Spare parts - fan shroud

@gglockner

The only issue is melting/sagging over time.  If you print higher temp stuff (that includes PETG) the shroud will eventually sag and deform if it is printed in a material that doesn't stand up to high temperatures.  If you only print PLA at ~200C you're fine but if you print PETG or PC or something else at 240C+ then it will droop because it is soaking in that heat.  Prusa uses ABS/ASA for that reason and many of us have also used things like PC, PCBlend, etc. that handle that heat well.

RE: Spare parts - fan shroud

Good materials for high temperature use are cellulose lactides and certain grades of polylactide.

Cellulose lactides will usually stand 100°C without annealing and up to 140°C after annealing, high temperature polylactides almost always need annealing for temperatures over 55°C, but after annealing can match the annealed Cellulose lactides.

The only two brands of Cellulose lactides of which I know: Extrudr (Greentec & Greentec Pro) and Fillamentun (NonOilen).

All these are almost as easy to print as conventional polylactides (they just need a little higher nozzle temp).

RE: Spare parts - fan shroud

Tis so small, that fumes are not going to be an issue.

RE: Spare parts - fan shroud

I have printed fan shrouds in nylon X, ABS, PC Blend, and ASA - All will work.