MK4s Upgrade Really Beneficial/Needed for MK4 with MMU3 Already Installed? - General discussion, announcements and releases

RE: MK4s Upgrade Really Beneficial/Needed for MK4 with MMU3 Already Installed?

darksharpie — Sat, 08 Feb 2025 20:06:02 +0000

Yeah, I wonder if they can do that, since the umbilical is in the way on the MK4s. On the CORE One, it attaches to the top so there's empty space behind the toolhead and that's right where the fan and its extension sit.

Posted by: @sweetride
I like the S upgrade, but damn, that fan should be hanging out the back of the extruder. Maybe the + update will straighten that out for us.

RE: MK4s Upgrade Really Beneficial/Needed for MK4 with MMU3 Already Installed?

Desktopbob — Sat, 08 Feb 2025 17:08:08 +0000

I like that idea, Stick the FAN on back side of the Nextruder! 👍 👍

RE: MK4s Upgrade Really Beneficial/Needed for MK4 with MMU3 Already Installed?

SweetRide — Sat, 08 Feb 2025 16:45:52 +0000

I like the S upgrade, but damn, that fan should be hanging out the back of the extruder. Maybe the + update will straighten that out for us.

RE: MK4s Upgrade Really Beneficial/Needed for MK4 with MMU3 Already Installed?

Desktopbob — Thu, 06 Feb 2025 01:44:50 +0000

Seems like they could have come up with a better design that still used the swinging door to open and move the monster fan out of the way to change nozzles. I didn't install it. I did everything else, the WIFI the new fancy injection molded bezel the nextruder feeder parts. The stock fan works well enough for me with the better duct work others have designed.

RE: MK4s Upgrade Really Beneficial/Needed for MK4 with MMU3 Already Installed?

Volker — Thu, 14 Nov 2024 19:40:38 +0000

I ordered the upgrade immediately, because I want my printer to be as updated as possible. I did not modify the y-belt holder, because I’m satisfied with the old one (I’m using a modified belt tensioner). I think the new fan and the HCT nozzle is worth the upgrade. You can order just those as a spare part and get it cheaper - but who is looking always on savings??

RE: MK4s Upgrade Really Beneficial/Needed for MK4 with MMU3 Already Installed?

Sembazuru — Thu, 07 Nov 2024 20:15:14 +0000

I know that I wasn't directly asked, but I also always use socks. I started on my MK3 (and used the wire core of twist-ties to hold the top of the sock closed on the E3D V6 style hotend). When I first built my MK4 I installed the sock before my pre-flight testing, had an issue with the initial heater calibration until I turned on the sock switch in the nextruder settings. Haven't had a problem with socks since. Then I discovered the Sock-X line (I think Levendigs is the origin of that brand) with the different colored socks. Now I have a nice collection, see my makes for the nextruder nozzle organizer and the nozzle sign/plate for Nextruder organizer.

My justification for using socks is to keep the part cooler fan from fighting with the nozzle heater, keep whisps of filament (especially stringy PETG) from getting on my heater block and burning and then dropping off into a print, and to color coordinate to my nozzles to my nozzle labels.

I just started using the Sock-X socks, and find them thicker and slightly stiffer than the official Prusa ones. But I don't know how long they will hold up yet.

RE: MK4s Upgrade Really Beneficial/Needed for MK4 with MMU3 Already Installed?

Pepan — Thu, 07 Nov 2024 17:42:48 +0000

I used sock even on MK4, so I continued to use it also on MK4S and I dont run into any error so far (I only need to solve layer shifting with variable layer height - but thats maybe not related to mk4s - I used it first on mk4s).

I read earlier, sock can help with temperature stability, so I started to use it without much more thinking about it.

RE: MK4s Upgrade Really Beneficial/Needed for MK4 with MMU3 Already Installed?

bowtie6 — Thu, 07 Nov 2024 16:42:08 +0000

@Pepan - Since you are pleased with the upgrade, have you experienced any temp runaway issues? Do you print with the sock attached? There is a thread about this and was wondering what your experience/thoughts are about the sock.

RE: MK4s Upgrade Really Beneficial/Needed for MK4 with MMU3 Already Installed?

Pepan — Thu, 07 Nov 2024 13:34:53 +0000

For me the upgrade was great. I appreciate better cooling and higher speed. The thing is, you dont get any (or only small) benefits by using same layer height (e.g. 0,2). You have to use 0,25 or 0,28. I didnt compare actual profile settings. Only times of different layer heights on HF and nonHF profiles.

It seems like Prusa didnt want to crank up speed of printer to get the upgraded filament throughput. They simply (it seems to me) made layer higher (+ extruder faster) to reach new filament throughput speeds. On 0,25 I get almost everytime max (depends on filament, but usually around 24/25 mm3) througput. But if you dont want to use 0,25 layer height, I dont think new HF nozzle is for you.

Anyway, better cooling is great addon also with newer wifi module and nfc.

I compared only 0,4mm nozzle.

Now I use mainly 0,4mm HF nozzle and 0,25mm layer height. Thats ok for majority of my prints.

RE: MK4s Upgrade Really Beneficial/Needed for MK4 with MMU3 Already Installed?

iftibashir — Wed, 06 Nov 2024 22:16:04 +0000

Posted by: @rpgweb
I'd say skip this upgrade. I just finished installing my mk4s / MMU3 upgrade and i am rather disappointed by it. Probably my fault, i did not read enough on the upgrade before ordering it. However i did contact prusa tech support to ask if it was compatible with my mmu3 and they said, sure, no problem at all, it will work just fine. They never mentioned the HF nozzle and mmu limitations!
The problem is that it does work indeed, but i get absolutely no speed benefits from it. There was all those speed claims everywhere on the prusa blog and even some external reviewer about speed boost with nice charts...but in the end, if you have an mmu and do not install the HF nozzle you just have no speed gain. And even if you install the HF nozzle, you seem to get speed benefits only from the 0.25 printing profile if i am to believe the prusaslicer for the "Structural" preset.
The Speed preset might give you a boost at 0.20mm, i did not check. I prefer quality, so i mainly use the structural preset.
I was too quick to accept the speed claims without doing my due diligence :-(

I havent noticed any speed gains from the HF nozzle on MK4s TBH. I have a MMU3 waiting to be built, and I have no issue going back to a standard nozzle at all. The only benefit I really see is the new fan shroud allowing steeper overhangs of up to 70% - even then, I preferred the 'open' design of the MK4....