Prusa XL - What Finally Improved the Stringing!!! 

The XL was released before it was ‘done’. That puts buyers on the alpha and beta track. Until Prusa gets the XL to workhorse quality, we need to get the fixes as they come.

I think the factor that helps with the stringing when using input shaping is simply the speed and the profiles in Prusa slicer 2.7.0 alpha1 are just better adapted to that. As you can see, it also leads to slightly reduced overall quality like small layer shifts seen at 8:05 in the video. While the benchy doesn't look terrible and those wisps are actually to be expected, right where they are (it's a stress test after all), the strings dragged into the other color are different. If you look closely, they are rather short and thicker than the "cobwebs". That's because they are caused by something else and in a different situation, namely layer/color change. The same kind of stringing happens likely on those doors and windows too but since no color change occurs, it's a string of the same color (it's a trimming on the model). In Prusa slicer in expert mode you'll find under Print Settings/Advanced a point "Outer Perimeters First". Check that box please and see if that fixes anything. It should help keeping the comparable short strings inside the model, where it would be hidden in most cases. If that doesn't help, you can play around in Filament Settings/Filament Overrides. Here you can adjust the retraction parameters for each toolhead individually, without changing the defaults (try 40mm/s Retraction Speed for a start. if that does something, but gets you not quite there, try 0.8mm or 0.9mm as a retraction length. Even up to 1.5mm might do the trick for your filament ). If it doesn't help you can simply deactivate any change again by unticking a box. Temp and retraction settings work together like a set of gears. At lower temps the molten plastic is more viscous, which means if it is "sucked" up a syringe (which the hotend ultimately is), it will resist more but it will also resist the tendency to flow out the nozzle driven by gravity. The retraction is meant to cancel the effect of gravity for a moment. That moment is longer the more viscous the plastic is and the faster the solid filament drags on it, but at some point that effect will just break because the liquid will "rip". The last benchy was printed at 190°C, right? I'd say you can safely go to 195°C without much more stringing. The wisps may even get thinner. You are getting there, don't despair. Grant of the 3D Musketeers YT channel is currently building his own XL Fivehead from a kit. We are 2 livestreams in and I don't know when he will continue, but maybe contact him for his Friday podcast where he analyzes and suggests solutions for 3D printing problems of users who reached out to him. I'm pretty sure he will find your case interesting and has some advice.

This is an "Emperor has no clothes" moment for Prusa. The ardent fans won't criticize but everyone else sees there are some major unrealized potential there and it should not have been released in this state.

Again, I'm going to say thanks for all your time and effort. I came from a engineering profession and most of the people I did work for had no idea how much time and mental effort goes into perfecting a project. Keep uo the great work.

What I can see from all who own XL is they have unsatisfactory outputs. Thanks guys for sharing. That is definitely throwing my mind somewhere else than Prusa :)

Printing small objects is best done with smaller nozzles. The 0.6 nozzles in the XL are suited for large prints. Perhaps a test with an 0.4 nozzles would be worthwhile, at least for a two toolhead print.

With the new (alpha version) slicer it seems much better now. Wonder if you go back to the Owls with the same temperatures you did those how they would turn out with this combinantion.

On an ordinary printer you can simply check manually the lowest temperature for your filament if you simply set temperature on printer at 190C and manually feed the filament in and go lower and lower until you feel that the filament has too much resistance - it will be big change very sudden. Usually around 180C is lowest for PLA but that very depends you have to try it for your own conditions.

Another reason to not buy a XL I hope you can fix those problems … great videos by the way

I'm a perfectionist, so I see your last benchy as unexceptable in my eyes. Especially when my MK3S+ and MK4 are putting out beautiful prints. The XL cannot be sub par, it just can't. I'm starting to regret fulfilling my preorder the other day. Hopefullly by the time mine ships, Prusa will have worked out the quality issues.

I feel lucky to give up my preorder and jumped on a X1C😊

Try the same print with the default Generic PLA settings. If your 5 head reacts the same as my dual head, there will be almost no stringing.

Awesome job with your videos. You've been the best source for XL info over the last several weeks. I found the same thing: less stringing after alpha firmware AND alpha slicer. Josef happened to mention on their recent prusa podcast that the two were meant to be "used together". I'm wondering if that's a combination of some newer profiles that were loaded, and possibly the binary gcode option the two alphas support. A while back someone else found printers using Octoprint were pausing every so briefly because they could only send the gcode through the USB controller so fast and the same gcode on SD cards had no artifacts. Binary gcode is smaller but maybe that doesn't pause because of a bottleneck the same way regular gcode does. Have you had issues where your printer pauses and tells you to remove and reconnect the USB drive yet? I had that happen on a few prints, which were annoying, but the printer recovered from without any issue, I just had to be there to do that in order for the printer to continue.

I am glad you are getting it figured out!

That result looks about what I was getting from my Sovol SV04. However, that was with minimal purge on tool change and no purge tower. I should get back onto that, but it was taking up a lot of time. The trick was in playing with the tool-change g-code, and dialling in retraction well.

It still boggles my mind that the Prusa cant produce a good result. Even the last one shown with the benchie is sub-par and very rough. I would only use the XL for big objects that are simple to print. And then use your bambu lab for the smaller stuff.. i have 0 stringing on mine.

How can you not download the alpha software while being the alpha tester of the printer? :D The product isn't finished, you HAVE to get every newest alpha and beta there is.

It's not just your printer doing this but some of us with the MK4 are having similar problems with the Nextruder. At first I had to go much higher on my temps to get stringing lower on my MK4 and so I ordered another heat block assembly for other nozzles. When I ran the new assembly it needed lower temps like you had to do. I changed out the original heatblock with a spare thermistor and heater cartridge and then that one also now needed the 195 average temps to get stringing down. This is all with dry filament from my Sunlu S2 dryer. I never had such problems with my MK3+ or Mini+.

It definitely feels like you're making progress. Did you have the 3D Print Dogs gcode in this print as well, or no? Joel at 3D Printing Nerd has shown off a super high quality 5-color print he did on his XL. I kind of wish he'd publish something about what he tweaked to get it as good as he got it. I believe he said it was mostly temperature but he might have said something about retraction as well.

I'd just like to throw down my two cents since I haven't seen anyone mention this, but you might need to dry your filament. I think it used to be a pretty divisive about whether or not it was worth it, but it really depends on where you live and how humid it is. My understanding is that 50% humidity is, like, pretty bad. When you mention that your black and white filament rolls are the ones with the most stringing, I see that they're the ones most used; they've been left out the longest. I see your pink and grey rolls are practically brand new and had less stringing.

I would say update your retraction settings, I reckon that your retraction should be somewhere between 0.5-2 mm, though I don't have a prusa printer, so take it with a grain of salt, but definitely try to print a retraction tower...

Interesting, this entire time I assumed you had that slicer version, but I wonder what was changed that fixed it, as I don't recall seeing anything related in the patch notes. I do agree it looks quite a bit better, and personally as long as there are no smears I'd be satisfied, but it can definitely be better

For such a small print, i would use a .4 nozzle and maybe up retraction

Did you apply the 3DPrinDogs settings? You never mentioned that. I bet you will see a definitive improvement with their GCode.

I think the key is to lower your retraction-speed settings. Prusa slicer use very high speeds compared to other slicers and different speeds for retration and pushback speed. I always eliminate stringing when i get close to 30mm/s in prusa slicer on both numbers. Try to hold them equal. 30mm/s retration speed and 30mm/s pushback speed. Some materials absolutely don't like fast pressure changes while retracting. I hope it will work for you. Have a nice day and grettings from germany.

I would recommend to try some high quality PLA Filament. I did also have Overture and an Prusa XL, compared to Prusament there is a huge gap of quality. So maybe try another Filament.

Now bump the temp back up that is too cool I think for PLA

Temp towers are for picking the best temp for an individual filament, not color changes. The idea is to find the best temp for the individual filament and stick with it. White and black filaments can often have different temps because of how they radiate heat differently, black will tend to radiate heat better than white.

Love your vids! Hopefully my XL ist arriving soon. I am wondering If the new prusaslicer will Help against stringing and also the 6.0 Firmware Update (actually an Alpha Version)... Looking forward for more Videos !👍👍

Also, I recommend turning your fan speed a bit lower - (80% maybe?) especially if you're printing at these lower temps.

Prusa... it's the stringing formula itself. I hate never-ending tuning every single print job. Tech support advice is to lower the temperature. Then... why don't they lower the temperature in all their presets?

Hi, I noticed the gcode you used M109 I believe it is supposed to be M104.

Waiting so long after the preorder and pay so much money and then this... I would be so pissed

I’m really disappointed in my XL. I was expecting it to run like my MK3. In this day and age it should print better than it does out of the box.

I have XL 2T and running the alpha firmware with alpha Prusa Slicer. No serious stringing problems, although 0.4mm nozzle generally gives less stringing than 0.6mm. Luckily your problem was just a software based mismatch. I would have hated it if the "solution" would have been to just drop the temp.

Have you played with the retraction settings at all?

It's getting there...Do you feel its user, printer, slicer filament or firmware? I feel it's still not acceptable but if you think it's decent....

Did you ever figure out why your attempt to change temperatures with custom G-Code during your tower print didn't work. I have considered trying something similar with towers for part cooling. I had to change my Ender 3 S1 Pro part cooling fan. I upgraded to a 5015 with a trihorn plenum when I did. But I get more stringing printing PETG than I want. I considered just slicing a temperature tower with custom G-Code inserted but I was curious if it would actually work. I'm afraid Prusa-Slicer will just override my changes.

What about the room temp? Do you have an air condition or open window? What about retraction. Did you try to set it up differently?

Man I just put in a pre order for the 5 head and your videos and others I’m seeing are making me extremely nervous. Wonder if I should cancel and do the Bambu?

I have no experience with the XL, but I had the same issue on my RatRig V-Core when using the .6mm Nozzle. It seems like there is no chance to print with .6mm nozzles without stringing. After swapping to a .4mm nozzle it went away.

Did you set the z-hop to 0? That can help. Someone else on youtube had misaligned toolheads and that was contributing to the stringing problem

Try prusament or hatchbox, overture is crap and inconsistent from roll to roll.

I think you are making progress. Are you still using the 3D print dogs g-code changes? I think this is something Prusa needs to get a handle on. I got my main box today, so will start un boxing and building

Could you try a 0.4 nozzle on the XL? Still waiting for my 5 tool head XL but my old mk3s strings less or not at all with smaller nozzles. 0.25 nozzle doesn't string at all.

Did you take a snapshot of your settings before moving to 2.7. Be interesting to see if they changed anything, especially around retraction and wiping

Why not use the x1c and return the XL to prusa?

Your Getting there 😊

a lot of stringing can come from z lift where the filament is not properly wiped before moving off the model. Check printer settings -> extruder ->"lift Z" and "wipe while retracting". lower or eliminate the lift. and enable the wipe while retracting. Also see: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-XZTBSJAswbs.html I know you don't want to go there... but that's where you need to go.

From the video, it appears your nozzle seals are not set up properly.

The ending result is still not acceptable to me. No matter if it’s a MK3, MK4 with a MMU2/3 or XL 1 head or 5 there is no way you should see stinging like that. But, chunks of other filament mix into the other colors too? Nope. Not having it. Out of curiosity is there small bits of leftover filament on the underside of the hotend? I thought there was going to be some kind of stamping of the nozzle before the print head docks to make a more consistent tip without the tail. I know that most users almost never fine tune slicer for each brand, type of filament or for each roll used. They all can differ. If your an espresso junkie such as myself you will know each bag of beans differs from the next and that same bag will pull shots differently a few days to weeks into its use. It’s a pain and feels wasteful… but, it’s all part of 3D printing. All printers and or slicers need config and consistent maintenance it’s the nature of the beast. Nonetheless no print out of the box should be that bad off. The last print.. meh some tweaking sure. But, to tweak that much to just get that for result. Hmm. 🤔 I’ve never had to lower my temps that low in order to print pla. Sure I lowered the mk4 temp down for probing to help lessen the dots on the bed before printing. Makes we wonder why it’s so bad. I cannot see Prusa sending out an incomplete $4K printer. And I have seen others with nice multi color prints. Going to a 0.6 nozzle will take a little getting use too. I would do the torcher test record everything and contact chat. It’s a service you paid for. 😊

I don't get it. I have had perfect string free prints since day one with my 5 toolheads xl

What did the owls look like with both alphas…

great video but about Prusa: I mean u spend like almost 4k for a dammn Printer that doesnt even work perfectly in dammn 2023. I mean the concept is nice, but Im soo disapointed that they are literlly doing nothing against these problems and thats just a shame. Hope Bambulab gonna make a bigger one

I think it's still not where ist should be. But I see a 0.6 nozzle is far from ideal with such small items.

I think I saw someone else have this problem and it was because the nozzle seal wasn’t at the correct height here’s Prusa’s video of how to adjust the nozzle seal to the correct height. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-HDRa0PzoqtI.htmlsi=wNpo_NO6Jrh3ufDJ I think the nozzle seal is supposed to be as flush as possible so that the plastic can’t ooze out of the nozzle while it’s idle but the filament can stay at the nozzle to maintain pressure, then when the printer wants to use it again it doesn’t have a gap at the start of printing where it had to get back up to pressure in the nozzle. I would guess your nozzle seal is slightly too low as you can see the nozzle dragging filament back and forth from the dock sometimes. I would also give all the nozzles a good clean with a brush to get off any stuck filament.

You have patience like Job.

Please check out the podcast „3d printing today“ they explain the problem and the solution otherwise you won’t be printing PETG on that machine.

For the kin of price people are paying for this machine, it should be more polished.

Dry your filament, homie.

So sad that stringing issue on that powerful machine, but let's say you'll miss those "cute" strings when you'll finally fixed them 😀

still think the last benchy is really sub par. You managed to reduce the stringing slightly only to have the quality of the overall model look worse than what is capable by a budget level 3D printer. Prusa have really dropped the ball here and its blatantly obvious they have pushed out this printer way before it is ready. You should not be having to do all this messing around only to still have sub par prints on a printer of this price range.

Lol, this is just a basic setting. Everyone should know how to tweak it without help of other people. I'd return it to them at this point

Your paid 2000 dollars for a machine. There shouldnt be any "tinkering" for rhag much money. It should just work.

shocking for a printer in that price range. not what I would expect from prusa

$4000 and its not ready for prime time. Pass.

Looks like bambu wns again they dont release beta units they release tride and true units slow core xy lmfao