Corexy assembly needed a lot of fiddling around. I noticed X motor (? Left one anyway) had its pulley slightly too low. Opened up grub screws and moved it millimeter or two and noise seems to be gone now. However when I tried the homing tower test initial print looked really bad. Tried to tune belt tightness with Prusas application, but it's very bad. I couldn't get it work realiably at all even trying multiple phones and even BT microphone from Peltor headset. I'm not sure but I think latest Androids have some background noise suppression system that renders the application method useless with them. So tuned them by "feel" and first couple tries input shaper calibration failed, but in the end got it through and I think print quality changed to vastly better on second try. Picture attached.

So in the end things are now looking good for our XL. But very unfortunate that it had so many issues on assemblies from Prusa.

One cause of problems with the spooljoin function are the bent ends of filament used to hook the end into the spools of some manufacturers - the strong grip can cause underextrusion as the printer drags them free. If you check in with the printer up to a couple of hours before the run-out you can snip off the bent end before it causes trouble.

Cheerio

When it first happened I thought that was exactly the case. But since then I've tried to snip filament straight and even in 45 degree angle and it still can't push filament back from extruder to first sensor assembly. Though I yesterday had long conversation with support and they said they'll send me a new assembly and got the impression that it doesn't void warranty if I want to disassemble it myself. Actually got even link to its printed parts, which I might do, being small part after all. Anyway right after this post I'll begin to disassemble it see if there's like somekind of debris in the mechanism. It's not normal, like I mentioned in support conversation it takes like at least two times force to push filament even trough the sensor assy than it takes to push through MK3's apparently similar ball magnet assembly.

Cheerio

I followed the Prusa troubleshooting instructions for this exact problem and ended up blowing air into a small hole on the top of the Nextruder and that fixed it.  I was able to get filament loaded and resume the print. I suspect the ball bearing in the filament sensor got some debris in it and made it stick.  This has only happened to me 1x and I've easily done over 100 filament changes, probably hundreds, but that's not something I keep track of. 

I suspect in your case if the extruder is rattling on retraction for a filament change, that there might be excessive resistance for some reason behind the extruder.   The rattling you hear is likely the extruder motor skipping steps because it can't move the filament. 

I suppose there could also be an alignment issue of some kind in the Nextruder itself, but without being at the machine to diagnose I'm just guessing.  It's definitely not normal though.

My XL has been great.  Thousands of hours of flawless prints, with PETG, ASA, and PCCF. 

I will say it's not a printer for beginners because there are many challenges associated with large FDM prints that you don't have with the smaller bed slingers. 

I'm not sure what the previous poster issues are, but I've not experienced it.

I would definitely recommend an enclosure for ASA to help with warping and because of the fumes.  ASA has a tendency to warp, and this can be particularly challenging on large parts. 

Good luck in your decision.

Has your filament loading/unloading worked flawlessly every single time? Our machine has worked a single time. No matter if PLA, PETG or ABS. All bought from Prusa and never had issues with their filaments.

I will say it's not a printer for beginners because there are many challenges associated with large FDM prints that you don't have with the smaller bed slingers. 

I'm not sure what the previous poster issues are, but I've not experienced it.

I would definitely recommend an enclosure for ASA to help with warping and because of the fumes.  ASA has a tendency to warp, and this can be particularly challenging on large parts. 

Good luck in your decision.

All-in-all. Not happy at all. Hard pass for XL. I was getting exited to upgrade my home MK3S with Core, but hell no. I'm going to wait long and maybe even then do something I wouldn't like to do and get Bambu if I hear any negative things about Core. 

Let's face it. XL is very expensive single extruder printer and I at least personally expected it to function really well. Now it's like participating in some beta test 😒

To original post. I'd recommended looking out that Creality's what was it K2 Max or something? I've had one Creality years ago and it was quite meh printer and cause of that we skipped that option at work. But I'm now getting serious vibes we shouldn't have done that...

Currently, my goal is to produce small decorative pieces with some added functionality. My question about accuracy and layer height stems from wondering if I’m heading in the wrong direction since printer XYZ is said to be more precise.

The limits of FDM printing are dictated by physics and the MK2 generation of printers are/were capable of prints that hit those limits.  Since then all 'improvements' have been about recreating that accuracy with greater ease and faster.  If you need greater precision then filament printers are not the answer.

I currently run a MK3 and a 5h XL but I have also designed for the granddaughter of a fishing buddy who got a 'toymaking printer' for her birthday - it builds about 8cm cube - but the quality in PLA is indistinguishable.

Whilst the XL is capable of 'small decorative pieces' it is intended for larger work and mine is mostly used for practical stuff, mostly domestic but including light engineering parts, many for boatbuilding but increasingly for classic car spares.  The XL has given zero problems that were not obviously my own fault (trying to print TPU at PETG settings because I forgot which head was loaded with what and then overriding the warning was the messiest) and has been a true workhorse ... but it's very damp sensitive and you MUST dry all filaments before use.

European manufacturer.

Yes, it looks like there is going to be some sort of trade war so sourcing spares from US manufacturers is going to be prohibitive and probably as bad in the other direction for US users.   Many European manufacturers may even not bother with US sales for a few years if big tarriffs are applied.

the issue with Bambu Lab ... even though they eventually reversed the decision.

Read it carefully, it's more a rewording than a retraction.  This time I assume the Chinese governement are obliging them to route traffic through servers they can monitor and possibly they will insist on them installing backdoors in the machines' software to snoop from inside otherwise protected networks.

I'm not going to suggest a printer but I will suggest an additional purchase criterion - waste - if you are going with multimaterial or multicolour printing check how much filament is purged and wasted at each filament change.

Cheerio,