Too much part cooling after upgrade from mk4 to mk4s?  

RE: Too much part cooling after upgrade from mk4 to mk4s?

Yes, my failure rate is though the roof.  Its at the point now that I regret doing the Mk4 to MK4S upgrade, and wish that I can go back. I think there is way too much cooling that's causing the air to travel down the side of the print and lift the corners off the bed. Secondly, I think the printer is moving too fast and pulling the filament.  First layer adhesion is now an issue where it wasn't before.   My best advice is to lower the cooling way down and slow the machine down. Making this upgrade useless.

RE:

Same, my MK4S is less reliable than my MK3S ...

One in two prints comes slightly off the plate, problem occur with PLA and PETG, whatever I use the MK4S PEI sheet or my old textured or satin sheet.

I hope future software update can resolve the problem.

I hesitated between MK4S and Bambu lab X1C to replace my MK3S, I regrete a little bit.

RE: Too much part cooling after upgrade from mk4 to mk4s?

I'm afraid I have to concur. So far I've been unimpressed with the upgrade. My problems alternate between slight lifting at the edges to slightly to low first layer with ripples. All started with the upgrade. 

RE: Too much part cooling after upgrade from mk4 to mk4s?

Same. I am regretting the upgrade now as print quality has deteriorated. Prints are curling even with a brim, and I have poor layer adhesion with PETG. I have gone from producing perfect prints to creating landfill. I have wasted half a spool of Prusament on print failures. There clearly needs to be some Firmware tuning and tweaks in the slicer. Right now, Bambu Labs is looking mighty attractive. 

RE: Too much part cooling after upgrade from mk4 to mk4s?

Since upgrading, I've only had one successful print, and that had a base so warped the top layer was ruined.

Tried on brand new spools of Prusament, as well as a brand new print bed, doesn't matter, the print will not adhere. Definitely seems like too much cooling.

RE: Too much part cooling after upgrade from mk4 to mk4s?

To play devil's advocate the upgrade has worked great for me, no issues.

I have seen an improvement in part cooling.  I used to have issues with the backsides of the geometry that was directly across from the old fan setup.  This was especially obvious when there was thin geometry. I have seen a big improvement in those cases.  

I don't print much overhangs as I try to avoid them when designing so I can't comment on improvements there. 

As far as speed I always use the structural setting so no real difference there.

RE: Too much part cooling after upgrade from mk4 to mk4s?

Agreed I purchased the MK3s and had 4500 hours and never have an issue that wasnt my fault. yes it was slow but reliable. I purchased the MK4s upgrade kit and should have just  purchased the MK4  because  I gutted a perfectly good machine to get a ..........

Going to purchase a frame and carriage off FB market for 100 bucks an rebuild my MK3s

RE: Too much part cooling after upgrade from mk4 to mk4s?

I was on a support chat with Prusa support for 3 hours, and still couldn't resolve anything. All I discovered is if I just turn the fan off completely, my prints stick and don't warp, but expectedly the quality of the prints decreases. At this point, I think I'm just going to try and undo the upgrade and wait for them to iterate through software before I reinstall it.

RE: Too much part cooling after upgrade from mk4 to mk4s?

Are you guys using new HF filament profiles, or using your old filament profiles?

RE: Too much part cooling after upgrade from mk4 to mk4s?

Yeah, I'm using the HF profile. I ran through the wizard right after doing the upgrade. I've been having better success with the fan around 30% with pla parts that might warp.

RE: Too much part cooling after upgrade from mk4 to mk4s?

Posted by: @yossarianmtu

Yeah, I'm using the HF profile. I ran through the wizard right after doing the upgrade. I've been having better success with the fan around 30% with pla parts that might warp.

It's just odd because I've not had any issues and have not altered the fan settings at all.  I haven't printed any PLA since the upgrade as I mostly print PETG, but like in my earlier post I've only seen an improvement with the 360 cooling especially where there were thin sections directly opposite the old cooling fan setup. 

I hope everyone gets it figured out.

RE: Too much part cooling after upgrade from mk4 to mk4s?

I had some rough top surfaces and corner lifting on larger prints. I backed cooling off 15% and so far its been noticeably better.

RE: Too much part cooling after upgrade from mk4 to mk4s?

As far as what I've known in the past, yes. I have the Printer Profile set to the "Original Prusa MK4S 0.4 Nozzle" and the Filament Profile set to "Prusa PLA". Best I can tell, the filament profiles are the same between the different printer profiles, which seems odd since I'd think the HF nozzle should need different cooling.

RE:

Posted by: @cariboujim

As far as what I've known in the past, yes. I have the Printer Profile set to the "Original Prusa MK4S 0.4 Nozzle" and the Filament Profile set to "Prusa PLA". Best I can tell, the filament profiles are the same between the different printer profiles, which seems odd since I'd think the HF nozzle should need different cooling.

 

 4d0efa30-screenshot-2024-11-30-235758.png

Are you certain that the slicer profiles are correct for the MK4S?  For example, in my slicer, the print settings profile says "0.2 mm Structural @MK4S-IS 0.4". Yours is simply "0.2 mm Structural."  Each of the profiles in this drop down menu include "...@MK4S-IS o.4" at the end.  Likewise, my printer profile includes "...HF0.4" at the end.  Unless you have edited these names to shorten them, it seems possible that you might still be using incorrect profiles.

Also, I remember last year there were similar discussions on here about part curling, and I distinctly remember wondering if seasonal temperature shifts were playing a part.  Can you remember how close to the seasonal shift your "S" upgrade was done?  For certain folks, this could simply be incidental and not wholly associated with the updated cooling fan.  It seems clear that the vast majority of MK4 users (myself included) aren't having this problem, which makes me wonder if unique environmental conditions are at play.   

I have been running a Garolite built sheet (purchased from McMaster-Carr and cut down to size) for the last 5-6 months, and it seems to be a significant improvement over the Prusa smooth sheet.  You have to be a bit more careful not to scratch it when using a razor, but I use it reliably for PLA, PETG at the normal profile bed temps, and with TPU with bed heat turned off completely.  No need for glue or release agent.  Since the sheet is simply clipped on with mini binder clips, I no longer lift the sheet off to remove prints, but simply wait for the bed to cool down and easily pop them off by hand, even with PETG.  I also slow my first layer down to 30mm/s.

-J

RE: Too much part cooling after upgrade from mk4 to mk4s?

I believe I'm struggling with this problem too (though I wonder if there are contributing factors beyond overcooling). I'm using a new, factory-assembled MK4S and trying to print a part I've printed successfully hundreds of times on the MK3S. In 6 attempts on the MK4S I haven't had a success -- a corner always lifts off the bed and ruins the part. I've tried with the high-flow CHT and regular .4mm nozzles and their corresponding PrusaSlicer profiles. I'm using the "STRUCTURAL" preset.

I suspect the issue might stem from some combination of fast cooling, fast print speed, and the ~15° nozzle temperature bump (from 210 to 225 for PLA and the CHT nozzle) added to input shaper profiles.

Looking at all of this, I wonder if the problem would be addressed by a quality-oriented profile, or even just a non-input-shaper option. As far as I can tell the "Input Shaper" label in PrusaSlicer presets translates to something like "print it as fast as possible" as opposed to merely "do the resonant frequency compensation stuff." Currently there's no default profile (with or without input shaping) that allows you to simply turn off that "prioritize speed" switch in favor of part stability. But am I wrong here and just not seeing this option?

On my next attempt I'm going to try manually reducing the speed to 70% on the printer side and reducing nozzle temperature back to 210 in PrusaSlicer.

RE: Too much part cooling after upgrade from mk4 to mk4s?

Posted by: @teamd3dp

Are you certain that the slicer profiles are correct for the MK4S?  For example, in my slicer, the print settings profile says "0.2 mm Structural @MK4S-IS 0.4". Yours is simply "0.2 mm Structural."  Each of the profiles in this drop down menu include "...@MK4S-IS o.4" at the end.  Likewise, my printer profile includes "...HF0.4" at the end.  Unless you have edited these names to shorten them, it seems possible that you might still be using incorrect profiles.

As far as I know, these are what they should be. I went through the config wizard, and even unchecked all the options for the MK4 in the filament window.

For experimentation sake, I downgraded back to the MK4. (Removed the new cooling fan, removed the spacer from the nextruder, replaced the old cooling fan, changed the hardware type on the printer back to MK4, and ran through Prusaslicer's wizard again to set everything to MK4). I've now done 3 perfect prints that were large, without edge warping and managing to finish the entire print. (with exception of one, but that was due to using old filament in a multi-material print that snapped in the bowden tube)

So something definitely seems to be off. I print in an enclosure as well, and the ambient temperature usually floats around 80ºF.

RE:

@cariboujim

Keep in mind that there are multiple profiles in the slicer.  There is the print profile (on the Print Settings tab), the filament profile (on the Filament tab [this is the one that likely populates based on your check boxes in the image above]), and the printer profile (on the Printer tab).  Each of these include different settings that affect your print.  They all need to be setup specifically for the MK4S in order for things to run as intended.  I've included snips of what shows in my slicer for each of them.  (the lists have a scroll bar, so the filament profile image doesn't show the whole list).  I had to swap things over during my "S" upgrade also, and I remember at first I hadn't configured them all with the appropriate options.  It was a bit of a head-scratcher for a moment, but eventually I was able to set them up correctly.  If you are getting good prints when you swapped back to the previous hardware, that makes me even more suspicious that there is something profile related.  My guess is that in all three profiles (not just the filament profile) there are settings that adapt to the needs of the MK4S, and that you don't have those set.

-J

RE: Too much part cooling after upgrade from mk4 to mk4s?

What I wound up doing for PLA is lowering down the fan speed to Min 30% and Max 70%. Disable fan for first: 4 layers.  Full fan speed after: 6 Layers. Switch back to the smooth sheet, even though I think that's giving in. Lowered the printing speed down too. Now it's no faster then it was. About 20% faster then the mini's. But I will stick it out like this until the CORE XY upgrade comes in January, maybe that will fix the issues.  If not I will be switching over to Bamboo.  My brother already made the switch and does not regret it. I dont want to go that route just yet, I have been with Prusa since the beginning. But business is business and in business you need to be reliable.  All my printers run round the clock and reliability is necessary.   

RE:

I've been having better luck with warping after increasing bed temperature from 60c to 70c during printing. I also cleaned the bed with a bit of acetone which could be a factor, but I think it's mostly the temperature increase.

I have some thoughts about the MK4/MK4S PrusaSlicer profiles. I think their bias towards speed comes with a quality sacrifice that's too cumbersome to override in the current implementation. But I'll address this in a new post to keep this one on topic.