drooping fan shield  

Re: drooping fan shield

snip
watch that newly printed part, The prusa item is also abs, so yours may/will likely sag as well.

Mine (black) wasn't. At least it didn't react to Aceton. So I guess it probably was PETG, it had that shiny look to it.

Re: drooping fan shield

I too got a drooping fan shroud (black) that resulted in a couple of prints got shoveled around and plastics build up on the nozzle and fan.
Tested the shroud with Aceton, no reaction at all.
So probably it was PETG.

Printed a new one in ABS, and it seem to hold fine after 15 h of printing.

Silicone socks seems like a good idea.
I noticed that there are two variants:

https://e3d-online.com/v6-socks-pro-pack-of-3

https://e3d-online.com/v6-sock-3pack

Which one of them works best?

the clearances are tight, i do not think the pro will fit. and if it does, out of 3 only one will fit your 0.4 nozzle the other two would interfere with the filament flow. especially since these are consumables, after some time of high heat the silicone degrades and gets brittle and you have to replace

Regarding the Socks. I use them on 2 MK2S models and 2 MK3 models. You can always trim a little away on any of the pro nozzles for a perfect fit with an exacto. Worst case is that you end up with a regular version as opposed to pro afger trimming. That was my thought at least. I didn't know they were three different sizes and came upon my solution out of necessety, and haven't looked back since.

Re: drooping fan shield

Welp,

Count me in on the drooping fan shield/cooling duct.

Finally finished a lack enclosure and printed my first ABS print inside. 12 hour print and cabinet temps reached 100F/37.7C. Part of the shield/duck was sagging badly enough that I removed it for the next ABS print. Just a little lower and it was going to start striking the parts on the print bed. Not good. Going to add a sock and maybe print a new one with from ABS.

P.S. - The new poll would not allow me to vote.

Re: drooping fan shield

snip

Regarding the Socks. I use them on 2 MK2S models and 2 MK3 models. You can always trim a little away on any of the pro nozzles for a perfect fit with an exacto. Worst case is that you end up with a regular version as opposed to pro afger trimming. That was my thought at least. I didn't know they were three different sizes and came upon my solution out of necessety, and haven't looked back since.

Yeah, that was my thought as well.

Re: drooping fan shield

Mine started to droop as well... and I've only done one ABS print (about 3.5 hours in an enclosure that reached 37c).

I noticed it tonight after starting a second ABS print. The fan shroud had drooped enough that it was only about 0.5mm away from hitting the part. I was able to unscrew it and remove it while the print was underway. I was then able to press it firmly against my desk and re-form it to it's original shape (mostly).

That should enable me to keep printing in PLA until my sample of protopasta Polycarbonate-ABS Alloy arrives. I hope 50g is enough to print a fan shroud...

Re: drooping fan shield

mine too, after printing 6h with ASA (256c):

any idea how to solve the problem?

Re: drooping fan shield

Isn't the MK3 fan shield printed from the same material used on the MK2 and MK2S? I wouldn't think they'd change it and suddenly have new issues of these things melting. From my research, PETG requires a nozzle temp of around 240 while ABS is 255. Wouldn't anything around the nozzle (like this fan shield) be made up of at the very least ABS to prevent the heat from damaging it? I read about people shutting the fan off for printing ABS (apparently to prevent warping?), but maybe that is causing the issue. Not sure what Prusa recommends or if the fan should be on at least 20% to prevent the shield from being ruined. I want to order my first 3D printer soon (the MK3) and really like all the success stories of the Prusa printers along with the excellent support & community. But sometimes get worried I'm in for a major headache of issues as a complete newbie to 3D printing. Hoping the updated parts/firmware make the MK3 as good as the MK2S reviews/ratings are.

Re: drooping fan shield

i think the best solution is sadly to print in a better material due to the the deformation tempreture of the abs they use for the fan shield.
Fillamentum CPE HG100 could a filament to use as i asked filamentive about the temp that it starts to deform and got this as a reply:
"the Heat Distortion Temperature under load 0,455 MPa (66psi) is 80 °C. This is the temperature, when the test specimen bends one milimeter. This material has higher temperature resistance then ABS, PETG and other materials, so I hope, that you will be satisfied with the properties of our CPE filament." but i know someone said abs is 80c aswell but i dunno under what load.

Re: drooping fan shield

I noticed that Thomas Sanladerer's review of MK3 had a drooping fan too. 🙁

I reinforced my cooling solution (follow link in my sig) and added a clip. So now it is anchored in ~4 1/2 places so it should remain flat. It has more surface area to handle heat and no thin wings like stock. I have no sagging, but I haven't pushed it hard with several hour ABS prints.

Re: drooping fan shield

Yup, predicted this one and told Joseph to correct before production shipments. Guess nothing was done.
Do you have a sock? Highly recommended.

Just for $h!t$ and giggles I specified alternatives.

Melt estimate and costing is purely material (Shapeways processing fees minus shipping).

PC seems to be a good alternate. I did a 6 hr abs print first and then 1:30hr pc print and no drooping at all. and if you look at the proximity to the heater it is crazy close in this remix shroud. Not sure how this will stand up to nylon temps but i will eventually find out.

for anyone wondering it is the v10 shroud here, and i have swapped back to a PC version of the original prusa shroud.
https://www.thingiverse.com/thing:272054

20180127_144929.jpg
20180127_143229.jpg

Chris what make and colour PC did you buy please and if in UK can I get a link please, I looked at getting some from Rigid Ink but they only do a transparent one

Re: drooping fan shield

Mine started to droop as well... and I've only done one ABS print (about 3.5 hours in an enclosure that reached 37c).

I noticed it tonight after starting a second ABS print. The fan shroud had drooped enough that it was only about 0.5mm away from hitting the part. I was able to unscrew it and remove it while the print was underway. I was then able to press it firmly against my desk and re-form it to it's original shape (mostly).

That should enable me to keep printing in PLA until my sample of protopasta Polycarbonate-ABS Alloy arrives. I hope 50g is enough to print a fan shroud...

it's like 5g for the original.

Re: drooping fan shield

Chris what make and colour PC did you buy please and if in UK can I get a link please, I looked at getting some from Rigid Ink but they only do a transparent one

I originally printed in hobbyking clear PC and although it was the semi clear it worked wonderfully
but i wanted it to match so i bought some gizmo dorks black pc and that is what i have on the printer now

Re: drooping fan shield

mine too, after printing 6h with ASA (256c):

any idea how to solve the problem?

print a new one in a higher temp. I printed one in PC and you can see the pix at the beginning of the thread for how bad mine was

Re: drooping fan shield

Isn't the MK3 fan shield printed from the same material used on the MK2 and MK2S? I wouldn't think they'd change it and suddenly have new issues of these things melting. From my research, PETG requires a nozzle temp of around 240 while ABS is 255. Wouldn't anything around the nozzle (like this fan shield) be made up of at the very least ABS to prevent the heat from damaging it? I read about people shutting the fan off for printing ABS (apparently to prevent warping?), but maybe that is causing the issue. Not sure what Prusa recommends or if the fan should be on at least 20% to prevent the shield from being ruined. I want to order my first 3D printer soon (the MK3) and really like all the success stories of the Prusa printers along with the excellent support & community. But sometimes get worried I'm in for a major headache of issues as a complete newbie to 3D printing. Hoping the updated parts/firmware make the MK3 as good as the MK2S reviews/ratings are.

the manual says it is out of abs which has a glass temp around 100
i printed mine out of pc which is 120-130

Re: drooping fan shield

i think the best solution is sadly to print in a better material due to the the deformation tempreture of the abs they use for the fan shield.
Fillamentum CPE HG100 could a filament to use as i asked filamentive about the temp that it starts to deform and got this as a reply:
"the Heat Distortion Temperature under load 0,455 MPa (66psi) is 80 °C. This is the temperature, when the test specimen bends one milimeter. This material has higher temperature resistance then ABS, PETG and other materials, so I hope, that you will be satisfied with the properties of our CPE filament." but i know someone said abs is 80c aswell but i dunno under what load.

that is a lower glass temp than abs and right about the same as pet g.
i'd suggest Polycarbonate which is 110-130

Re: drooping fan shield

i think the best solution is sadly to print in a better material due to the the deformation tempreture of the abs they use for the fan shield.
Fillamentum CPE HG100 could a filament to use as i asked filamentive about the temp that it starts to deform and got this as a reply:
"the Heat Distortion Temperature under load 0,455 MPa (66psi) is 80 °C. This is the temperature, when the test specimen bends one milimeter. This material has higher temperature resistance then ABS, PETG and other materials, so I hope, that you will be satisfied with the properties of our CPE filament." but i know someone said abs is 80c aswell but i dunno under what load.

that is a lower glass temp than abs and right about the same as pet g.
i'd suggest Polycarbonate which is 110-130

So I tested the Raptor PLA which is 100C after annealing. It definitely holds up better than PETG. There is slight shrinkage when annealing, but if you have higher perimeters and infill it is minimal. But of course the fan shroud is thin and hollow and I'm not sure yet how to anneal it without it sagging (though I have not tried yet, just assuming). I'm going to trying slow "poaching" and see if that works.

Re: drooping fan shield

i think the best solution is sadly to print in a better material due to the the deformation tempreture of the abs they use for the fan shield.
Fillamentum CPE HG100 could a filament to use as i asked filamentive about the temp that it starts to deform and got this as a reply:
"the Heat Distortion Temperature under load 0,455 MPa (66psi) is 80 °C. This is the temperature, when the test specimen bends one milimeter. This material has higher temperature resistance then ABS, PETG and other materials, so I hope, that you will be satisfied with the properties of our CPE filament." but i know someone said abs is 80c aswell but i dunno under what load.

that is a lower glass temp than abs and right about the same as pet g.
i'd suggest Polycarbonate which is 110-130

So I tested the Raptor PLA which is 100C after annealing. It definitely holds up better than PETG. There is slight shrinkage when annealing, but if you have higher perimeters and infill it is minimal. But of course the fan shroud is thin and hollow and I'm not sure yet how to anneal it without it sagging (though I have not tried yet, just assuming). I'm going to trying slow "poaching" and see if that works.

print it at 102 or 105% in size so when it shrinks it doesn't cause you a problem

Re: drooping fan shield

I'm trying to print a replacement for my now drooping shield in Rigid Ink PC.

printing in an enclosure, @290C/130C and I can't get the PC to stick to the first layer. I've tried a fresh cleaned PEI sheet with IPA, and also with glue stick. I've tried dropping the speed down as well, any suggestions or hints?

Re: drooping fan shield

My results were merely acceptable with MK2S and Rigid Ink PC.
Perhaps with more tuning and risking thermal runnaway on nozzle might get better results but I'd PT100 or get a more tame PC (blends) before adding PC to stable.

Notes on my MK2S. Near hermetic enclosure capable of 52°C passively. Gold leaf lined nozzle area with thermally insulated bed.
2000 grit sanded (or fine steel wool) PEI, cleaned 99.2% Iso, 1 layer Magigoo.
295°C / 120°C, 0.2mm layer height, Slic3r 100mm/s LA setting divided by 5. Retraction 2mm at 60mm/s (arbitrary).
Used 120mm method to tune extrusion multiplier, saved in EEPROM but slicer setting is also fine.
Attempted to tune LA but got inconsistant results so settled on K40 with fingers crossed.

The print as you can see from photos is in my opinion barely acceptable. Layer adhesion was brittle but strong enough for duct duty. Attachment tab was a blobby mess but worked fine. Excessive stringing was a big problem even with aggressive retraction settings.

If I'd to do this again, I'd work with holed test cubes first (2cm cube with 7.5mm horizontal hole). Max travel but halve acceleration giving less time for stringing to thicken and increase extrusion multi to help low temp adhesion. I haven't yet tried the magic PC recipe on these forums but I've given up on Rigid Ink PC for now as I feel it needs more heat for numbers an LA to matter.

Re: drooping fan shield

I'm trying to print a replacement for my now drooping shield in Rigid Ink PC.

printing in an enclosure, @290C/130C and I can't get the PC to stick to the first layer. I've tried a fresh cleaned PEI sheet with IPA, and also with glue stick. I've tried dropping the speed down as well, any suggestions or hints?

I used the PC abs setting in prusa control 270c/110 for both and it seemed to print well enough. Only issue, the mount was a little squashed, I think if I'd use slic3r pe I'd set a minimum time of 10 or so seconds per layer.