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Dual Part Cooling Fan Mount / Shroud for Prusa i3 MK3S

by RosyRL Jun 17, 2019
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hI, It is possible fit on prusa Mk2s?

Unfortunately I do not know the difference between MK3S and MK2S by heart, and due to the fact that I had to undergo eye surgery I am, for the time beeing, unable to do research. Perhaps anybody else knows the answer? When I am back to business (two or three weeks from know) I can do any requested changes you might need. Greetz Rosy

What are acceptable replacement fans for this mod? I have not received my printer yet but am already planning my mods.... would like to get this information ahead of time and get fan(s) ordered. BTW, I am in the U.S.

I ordered mine directly via Prusa (beeing in germany it was the quickest option), but any 5015 operating at 5V will do. A two wire type is sufficient since you only connect the black and red wire to the original one and leave the yellow wire untouched,

How do you wire the second fan?
and what is That Z lift 0.15? Is it the Z lift on the retraction section? mine is set to 0.6 by default Whats the meaning of this seting?
btw Great design, still waiting for that second fan

You only need to connect the second fan to the red and black wire of the first fan. Yellow wire remains unused. I did it by simply cutting the red and black about half way from fan to extruder-body, twisted them together and used heat-shrinking-tube to finalise.

Regarding Lift Z:
Yes, it's the setting in the retraction section. When printing materials that tend to stringing (like PETG) reducing this value from default 0.6mm to about layer-height-value helped a lot to reduce stringing. What this value means: When changing printing spots the filament is "sucked" into the extruder to prevent it from oozing out of the nozzle while moving to the next spot, this is called "Retraction". While "sucking", the nozzle is "wiped" about 2mm along already printed layer to give it time to stop oozing. Then the nozzle is lifted up by a certain amount (called Lift-Z or Z-Hop) prior to moving to the next printing spot where it again starts to extract filament. This "lifting movement" is done to prevent the nozzle from catching into already printed parts that may have "warped-up" a bit. After installing the dual-fan-shroud this warping is nearly fully eliminated in my case, depending on material, overhang value and printing speed used, I can fully disable Lift-Z (set to 0mm) which, in my case, makes stringing to be no issue any more even when printing PETG. You can find a lot more info on this subject here: https://manual.slic3r.org/expert-mode/fighting-ooze

Greetz Rosy

Sweet! Thank you for that! Btw, the part printed fantastic! Well designed.
I'll post some pics when the second fan will arrive.

First few prints this worked great, but over time it seemed to deform and started dragging one fan along the bed. I tried this out of PETG, so I probably just need to move up to ABS for temperature resistance. Good design, just need to pick the right material.

Hi :), dual fan still working great, i have struggles to print the 50% scale lattice cube, can you share the speed / temp settings you used ? Thanks !

Normally i save the .3mf file when i'm testing, but i can't find this one... If i recap it correctly i used my miniature settings for the 0.4mm nozzle, which are basically the stock 0.2mm quality settings and following changes: ensure vertical shell thickness: NO; 0% infill; Extruder 200 degrees (first 210) Bed 60; Min print speed 10mm/s; Lift Z 0,15mm !!! . Resulting in a print time of approx 1:30h.
I think i did cut off a bit of the "base" of the cube leaving only 3 or so bottom layers to speed up printing.

Hi tanks for the model, however i have alignment problems with the screw that pass through the hotend fan, it's me or the model ? Can't manage to place it properly

Hello F0x06,

there must have gone something wrong! Possibly during slicing?
Before inquiring any further, I would like you to measure the distance as shown in the Foto. Should be exactly 20mm.
The model and the uploaded file are correct. I just downloaded it and put it into Fusion 360 to recheck.


With a bit of force (no so much) i managed to install the part, also i cleaned a bit the edges from some blobs. The quality with dual fan is impressive ! it completely solved my bad overhangs at rear of the nozzle

If you like the performance then do me a favor and thank Jonathan for the design in https://www.thingiverse.com/thing:2978427 ...
My job was "only" the reconstruction of the mounting so that it fits to the MK3S.

Greetz Rosy

Dual Part Cooling Fan Mount / Shroud with Nozzle View for Prusa i3 MK3

Thanks Rosy, I got his comment, and came here to pass it on in the other direction! :D

Thank you for the design, i'am interested in using it with the mosquito hotend version of the extruder (https://www.thingiverse.com/thing:3515782), iis based in R4 design so it fits quite well but there is one slight issue with the arm connecting to extruder body. because the hole is slightly moved to left the whole mount is angeled.
Any chance you can release a version with hand move like 3mm left or maybe share source files so i will try and remix it please ?
I am attaching photo of the misaligned screw.

Otherwise the design is excellent and works well so far.
Thank you.

Prusa MK3s/2.5s/MMU2s Mosquito Hotend Extruder

Hey glezz,

check this out ... https://www.thingiverse.com/thing:3711093

You're welcome.

MK3S Mosquito Dual Fan Shroud
by RosyRL

I have very similar design for bondtech upgrade mk3, but it suffer to bad resonation due to second fan. Don't you noticed it on this one?

My second fan will arrive tomorrow, so i cannot answer it yet. But what i immediately noticed after installing this and testing it with only one fan, was that the printer is noticeably more quiet! I had some annoying high pitch rattling noise when the Z axis moved, that is completely fixed after installing this thing. Possibly due to the upright mounting position of the fan? I will inquire this further...

Greetz Rosy

Merci beaucoup pour le travail

You're my hero! Thanks for putting this together - it's been on my list but I'm super duper busy with a new job at the moment! <3

Excellent. Does this fit if using a silicone sock?

Just added a foto of the heatblock with sock and the dual-fan-mount installed. Hope that it is okay....

Yes, i am using E3D original sock and it fits beautiful. Tried to make a foto from below the extruder, but didnt succeed due to bad lighting... Will try again tomorrow in daylight conditions and post it.

Awesome. Cheers bud.