Material choice for updated fan duct on MK3S  

RE: Material choice for updated fan duct on MK3S

Also, why ABS and not ASA? I thought ASA was better and less odor.

RE: Material choice for updated fan duct on MK3S

You can use PETG, just pick one of the more reliable brands.  The biggest issue with using PETG for the fan duct is that different manufacturers have different recipes and quality of ingredients in their PETG.  One brand may be fine, whereas another brand you might end up melting.  I wouldn't recommend a "budget" brand of PETG for something like a fan duct.  If you need a place to start, look into Taulman3D.  They have been making high quality engineering grade filaments for years now.  Many of their products are developed with 3M which is basically the main player in chemistry for plastics.

You can absolutely use ASA instead of ABS.  ASA is just as strong mechanically as ABS and ASA also has a higher heat tolerance as well as better resistance to UV light (if you ever need to print something that is going to sit outside for its lifetime).  ASA probably isn't mentioned because it isn't as widely known as ABS and those that are aware of it more than likely already know that most ABS parts can be directly substituted with ASA parts.   

RE: Material choice for updated fan duct on MK3S

I currently use PC blend.  ASA and ABS are also good alternatives.  If you are printing just PLA, I see no reason you could not use PETG.  

RE: Material choice for updated fan duct on MK3S

Thank you both for your responses.

I have the Prusa orange PETG. I can use that, but what materials would require aa higher temperature setting where the PETG would be problematic to use for this fan duct?

Thanks!

RE: Material choice for updated fan duct on MK3S

Another question, I'm assuming that to replace the fan duct I have to remove the whole extruder from the assembly so I will have to redo the z-height adjustment, etc.... Am I correct?

RE: Material choice for updated fan duct on MK3S

@chrisdmd

I recommend to do so after every maintenance work on the extruder, but you can test beforehand if it still fits.

who wants it extreme:

I tested this material for my fanshroud: https://www.3dxtech.com/carbon-fiber-filaments/carbonx-peek-cf/ -> result: the part withstands nearly everything.

This material is also suitable and can be printed more easily and without extensions (high temp nozzle and bed): https://www.3dxtech.com/carbon-fiber-filaments/carbonx-nylon-pa6-cf/

I tested this materials on the MK3 because otherwise I use it to print robust parts for special machine construction and my car.

RE: Material choice for updated fan duct on MK3S

Posted by: @chrisdmd

Another question, I'm assuming that to replace the fan duct I have to remove the whole extruder from the assembly so I will have to redo the z-height adjustment, etc.... Am I correct?

When I disassembled the extruder to do the MMU2S upgrade, the Z cal value did not change at all.  I did check it very carefully, however.

RE: Material choice for updated fan duct on MK3S

Posted by: @chrisdmd

Another question, I'm assuming that to replace the fan duct I have to remove the whole extruder from the assembly so I will have to redo the z-height adjustment, etc.... Am I correct?

Incorrect. It’s just 2 screws that holds the parts fan in place. Just remove them and the existing one will come off. Then simply fit your new one in place, reversing the steps. 

RE: Material choice for updated fan duct on MK3S

Thank you all for the responses!!

RE: Material choice for updated fan duct on MK3S

@neophyl

Unless I'm doing it wrong, this particular fan duct upgrade requires taking off more than the just the 2 screws. Now I see what it has another part to print with the fan duct. Can you recommend another fan duct upgrade where I don't have take apart the extruder?

RE: Material choice for updated fan duct on MK3S

Please correct me if I’m wrong but do you have a mk3s ?  If so then to remove the actual fan duct it’s just a single screw.  Step 38 from here https://help.prusa3d.com/en/guide/5-e-axis-assembly_28536. It’s the bottom right screw that goes through the hot end fan and secures into the nut in the fan shroud.   If you want to remove the fan as well then that mounts to a support piece, you can either remove the fan from the support or remove the support still connected to the fan. That was the 2 screws I mentioned. 
The replacement duct you linked to in the first post, the CS one requires a slightly different support bracket which is why there are 2 parts. But it’s hardly talking the extruder apart. One screw to change the support bracket, one more to fit the fan to the new bracket and then the new fan duct goes back on with a single screw like the old one did. 
At no point does the extruder come apart or do you touch the hot end itself. 

RE: Material choice for updated fan duct on MK3S

@neophyl

Thank you so much for explaining this to me. I was getting a little confused and misunderstood. I understand it now.  Thanks again!

RE: Material choice for updated fan duct on MK3S

Guys, my original mk3s fan duct is melting after hour long printing of ASA. It seems it cannot withstand the 260/110 degrees celsius. I already reprinted the original in ASA but got the same warped duct after a few prints. Do you know any alternatives in Design or better materials I could use? I found this one: https://www.prusaprinters.org/prints/1807-prusa-mk3s-upgrade-fan-duct/files , printing it in ASA right now. 

RE: Material choice for updated fan duct on MK3S

I did the remixed fan shroud using the new(er) Prusa PC Blend.  I had a spare using ABS, but I'm keeping that in the crash kit.

I replaced it after the original began to droop slightly after a whole run of ABS prints.

I figured it was as good of an excuse as any to try the PC Blend.

When I did the replacement I re-ran the 3x3 Z calibration test and found no difference from the last time I ran it.