As of 6.4.0, the XL still crashes toolheads into one another. It is inexcusable.
 
Notifications
Clear all

As of 6.4.0, the XL still crashes toolheads into one another. It is inexcusable.  

Stránka 1 / 2
  RSS
ktastrophe
(@ktastrophe)
Eminent Member
As of 6.4.0, the XL still crashes toolheads into one another. It is inexcusable.

Latest firmware. I do not want to hear that this is a filament drying problem, or something I should expect from such irredeemably ancient technology as a three year old printer, or that this is just the way that tech is, or what have you. This is not user error. This did not happen because of improper build surface preparation, nor did it occur because of some error on my part in slicing. Screws backing out cannot cause this. Improper assembly does not cause this. Wrong torque values also do not cause this. This printer passes calibration tests very reliably. This happened because the latest firmware still cannot recall what tool it is holding. 

That is a build plate full of ruined PCCF Prusament, which costs 65 dollars per 800g. It is ruined because the XL attempted to park toolhead 1 where toolhead 2 is.

This machine has done this intermittently on every firmware I've used for it. It has done it for multiple other users. 

https://forum.prusa3d.com/forum/original-prusa-xl-multi-tool-upgrades-hardware-firmware-and-software-help/toolchanger-with-tool-2-strikes-tool-1-on-dock/

I cannot imagine this is a very hard problem to solve. Is there some reason the firmware cannot keep track of which toolhead is where? Is the combinatorial complexity of this task beyond that of calculating Ramsey numbers or some such thing? Or rather, I posit the following: it is exemplary of how abandoned this machine is. I am done claiming "it's abandoned but at least it works", because it doesn't. I probably have a 50% build failure rate. The XL has been utterly abandoned. I am not satisfied with a silicone toolhead, because I do not wish to waste specialized silicone material. I do not wish to randomly drop nuts and magnets all over tarnation with the pick and place toolhead. I wish, in fact, for this nearly 3000 dollar printer to work as well as the 10+ MK3S printers I have owned over the years. 

This is not hyperbole. Please fix this issue. Thanks. 

Napsal : 07/01/2026 2:07 am
1 lidem se líbí
jan.d.slay
(@jan-d-slay)
Estimable Member
RE: As of 6.4.0, the XL still crashes toolheads into one another. It is inexcusable.

I was also hoping to own an XL that would work just as stably with the 6.4.0 firmware as it did with 6.2.6. Unfortunately, I was wrong.

Prusa Core One - Fast & Clean Start Gcode
Prusa XL - Quick Start Gcode
Napsal : 07/01/2026 3:17 am
1 lidem se líbí
ktastrophe
(@ktastrophe)
Eminent Member
Topic starter answered:
RE: As of 6.4.0, the XL still crashes toolheads into one another. It is inexcusable.

 

Just attempted to print this again. Check that out. Another wasted ten bucks or so. Why? Because it crashed toolhead 1 into toolhead 2 again.

So what do I do now? Go start inspecting firmware source code, tweaking settings like I did in 2016? Go buy a Bambu so they can steal all my data? Because this is simply not acceptable at all. This is not a hard problem to fix. 

Napsal : 07/01/2026 6:04 am
jan.d.slay
(@jan-d-slay)
Estimable Member
RE: As of 6.4.0, the XL still crashes toolheads into one another. It is inexcusable.

This is not a hard problem to fix. 

That's correct.

Reinstall firmware 6.2.6 and be happy that the printer is doing what it's supposed to do again.I had similar problems to yours after I wanted to test 6.4.0.

Since I reinstalled 6.2.6, my XL has been printing again without interruptions, day after day, for hours on end, without a single ERROR.

Just try it, you'll be surprised.

Prusa Core One - Fast & Clean Start Gcode
Prusa XL - Quick Start Gcode
Napsal : 07/01/2026 6:55 am
ktastrophe
(@ktastrophe)
Eminent Member
Topic starter answered:
RE: As of 6.4.0, the XL still crashes toolheads into one another. It is inexcusable.

 

Posted by: @jan-d-slay

This is not a hard problem to fix. 

That's correct.

Reinstall firmware 6.2.6 and be happy that the printer is doing what it's supposed to do again.I had similar problems to yours after I wanted to test 6.4.0.

Since I reinstalled 6.2.6, my XL has been printing again without interruptions, day after day, for hours on end, without a single ERROR.

Just try it, you'll be surprised.

Ugh. 3000 dollar printer. Just ugh. 

Napsal : 07/01/2026 6:56 am
jan.d.slay
(@jan-d-slay)
Estimable Member
RE: As of 6.4.0, the XL still crashes toolheads into one another. It is inexcusable.

Do not touch the running system.

With firmware 6.4.0, Prusa has not done the XL any good (in my opinion)

 

 

Prusa Core One - Fast & Clean Start Gcode
Prusa XL - Quick Start Gcode
Napsal : 07/01/2026 7:02 am
1 lidem se líbí
Prune
(@prune)
Active Member
RE: As of 6.4.0, the XL still crashes toolheads into one another. It is inexcusable.

The worst in all that, is that there's not any official answer or comment, or official documentation stating to NOT update the XL until this is fixed... What are you doing Prusa ? Is Core-one driving you away from your 10+ years users ?

Napsal : 07/01/2026 1:01 pm
1 lidem se líbí
Showy07
(@showy07)
Member
RE: As of 6.4.0, the XL still crashes toolheads into one another. It is inexcusable.

I recently acquired a Prusa XL 5TH, which I ordered unassembled. After lot of hour for assembly and initial calibration (the only error was with the fans at first, which was corrected by adjusting the screws), I immediately updated to version 6.4.0. After 15 days of use and about twenty prints, I've only encountered two false error messages related to filament jamming. I've printed PLA and PETG and used all five nozzles. Everything is working perfectly so far.

Napsal : 07/01/2026 2:07 pm
Ro3Deee
(@ro3deee)
Trusted Member
RE:

Also contact support. If you can duplicate the problem, consider creating an issue on firmware github https://github.com/prusa3d/Prusa-Firmware-Buddy/ , as I did. 

For me it works. Here is a video https://youtube.com/shorts/MQ4M1ajjnkM?si=zUZmHoMfdVeYJzMg

 

Napsal : 07/01/2026 2:32 pm
1 lidem se líbí
FoxRun3D
(@foxrun3d)
Illustrious Member
RE: As of 6.4.0, the XL still crashes toolheads into one another. It is inexcusable.

The 6.4 RC was certainly a massive stinker that should never ever have seen the light of day, with brutal crashes. 

After installing 6.4 I did a few prints without issues, and now my XL-5T has been running for almost two weeks non stop no problems. 

I don't know why some people have continuing issues, others don't. I have a day one model so if anything I would expect to be more likely to be impacted. 

The only thing I did after the 6.4 upgrade was to redo the toolhead calibration.

Formerly known on this forum as @fuchsr -- https://foxrun3d.com/

Napsal : 07/01/2026 3:12 pm
Prune
(@prune)
Active Member
RE: As of 6.4.0, the XL still crashes toolheads into one another. It is inexcusable.

Well, at least:

- https://github.com/prusa3d/Prusa-Firmware-Buddy/issues/5072

- https://github.com/prusa3d/Prusa-Firmware-Buddy/issues/5055

- https://github.com/prusa3d/Prusa-Firmware-Buddy/issues/5061

- https://github.com/prusa3d/Prusa-Firmware-Buddy/issues?q=is%3Aissue%20state%3Aopen%20label%3A6.4.0

are bugs people are having.

I'm personally having issues with the "clogged nozzle" or whatever you call that. I'm also exclusively printing PTU (FLEX) filament lately, which may also be related...

I'm really glad you're not impacted, but seeing the list of opened issue, I doubt we're just unlucky...

Posted by: @foxrun3d

The 6.4 RC was certainly a massive stinker that should never ever have seen the light of day, with brutal crashes. 

After installing 6.4 I did a few prints without issues, and now my XL-5T has been running for almost two weeks non stop no problems. 

I don't know why some people have continuing issues, others don't. I have a day one model so if anything I would expect to be more likely to be impacted. 

The only thing I did after the 6.4 upgrade was to redo the toolhead calibration.

 

Napsal : 07/01/2026 4:12 pm
1 lidem se líbí
FoxRun3D
(@foxrun3d)
Illustrious Member
RE: As of 6.4.0, the XL still crashes toolheads into one another. It is inexcusable.

Yeah, I'm aware of those GitHub issues, unfortunately. And I certainly count myself lucky! Prusa software generally has been slipping for a while, and this round of firmware has been — rough. No idea why they can't catch those issues in internal testing.

Formerly known on this forum as @fuchsr -- https://foxrun3d.com/

Napsal : 07/01/2026 6:49 pm
Gerald
(@gerald-6)
Active Member
RE: As of 6.4.0, the XL still crashes toolheads into one another. It is inexcusable.

Bonjour

C’est simple à comprendre, cette version n’a tout simplement pas été tester sur cette imprimante XL.  Depuis que j’utilise les imprimantes PRUSA, jamais, je dis bien jamais un firmware a réunis autant de bog. Comment peut on avoir une version 6.2.6  fiable et la remplacer par cette maudite version 6.4.0. Bref, il est maintenant impératif de fournir rapidement une V 6.4.1 corriger et tester sur une imprimante XL et non pas sur une Core One.

Napsal : 08/01/2026 9:37 pm
Gerald
(@gerald-6)
Active Member
RE: As of 6.4.0, the XL still crashes toolheads into one another. It is inexcusable.

Bonjour

C’est simple à comprendre, cette version n’a tout simplement pas été tester sur cette imprimante XL.  Depuis que j’utilise les imprimantes PRUSA, jamais, je dis bien jamais un firmware a réunis autant de bog. Comment peut on avoir une version 6.2.6  fiable et la remplacer par cette maudite version 6.4.0. Bref, il est maintenant impératif de fournir rapidement une V 6.4.1 corriger et tester sur une imprimante XL et non pas sur une Core One.

Napsal : 08/01/2026 9:41 pm
Gerald
(@gerald-6)
Active Member
RE: As of 6.4.0, the XL still crashes toolheads into one another. It is inexcusable.

Bonjour

C’est simple à comprendre, cette version n’a tout simplement pas été tester sur cette imprimante XL.  Depuis que j’utilise les imprimantes PRUSA, jamais, je dis bien jamais un firmware a réunis autant de bog. Comment peut on avoir une version 6.2.6  fiable et la remplacer par cette maudite version 6.4.0. Bref, il est maintenant impératif de fournir rapidement une V 6.4.1 corriger et tester sur une imprimante XL et non pas sur une Core One.

 

Napsal : 08/01/2026 9:43 pm
ktastrophe
(@ktastrophe)
Eminent Member
Topic starter answered:
RE: As of 6.4.0, the XL still crashes toolheads into one another. It is inexcusable.

6.2.6, printer passes all checks. We have wasted about one complete roll of PCCF Prusament. I do not trust this thing to print a Benchy. Random heatbed failure. Random layer shift. 

Again. And again. And again. On a 3000 dollar machine. Prusa has said nothing. See, the problem is this: If Prusa's printers suck, then as far as I'm concerned, there are no good printers. 

Napsal : 12/01/2026 12:35 am
Brian
(@brian-12)
Noble Member
RE: As of 6.4.0, the XL still crashes toolheads into one another. It is inexcusable.

It's odd that your having so many problems with it. 

I'm running 6.4.0 and have been printing pretty much non stop for the last 2 weeks with prints using 2 tool heads of PETG and 90A TPU.  I even used spool join on 1 print as I emptied a roll of petg.

I did have some weird artifacts on a free prints, but narrowed that down to a big in the latest version of PS.  I downgraded to the previous version and no more problems. 

I also did 2 prints with PCCF which I run dedicated in head#5.  They weren't real long prints, only about 8 hours, but no issues. 

Is it possible you've got a bad calibration on tool head positions? Something's going on mechanically I think, or else everyone would have crashing heads, which I haven't had happen in over 2 years. 

Napsal : 12/01/2026 1:13 am
ron
 ron
(@ron)
Estimable Member
RE: As of 6.4.0, the XL still crashes toolheads into one another. It is inexcusable.

@ktastrophe

You are not alone. In 2.5 years, my rate success of printing should be about 25%. For a 24h+ printing, it is about 0%. I rarely use it depites my need to have a multimaterial printer. I prefer my Voron for 1.5kg printed parts which has a ~100% success rate.

Tested all Prusa recommendations for the latest 6.4.0. Decreased all the speed an accel down to those of the XL without input shaping profile.

Latest PETG one tool:

Napsal : 13/01/2026 3:26 pm
Brian
(@brian-12)
Noble Member
RE: As of 6.4.0, the XL still crashes toolheads into one another. It is inexcusable.

I have to think something is calibrated wrong or assembled wrong in your printers.  How could I have so little issues and you so many.

Here's a print I did a few months ago, 25 hours with 2 tool heads, but primarily PETG.  I printed this a total of 3 times in a row, all completed and are currently hanging over my aquarium.

 

 

Napsal : 13/01/2026 5:17 pm
1 lidem se líbí
FoxRun3D
(@foxrun3d)
Illustrious Member
RE: As of 6.4.0, the XL still crashes toolheads into one another. It is inexcusable.

It is odd. My XL-5 is the printer I trust most. More than any of my Core Ones. It pretty much performs like my old Mk3S's, which were start-and-forget. I have no idea why the experiences seem to be so all over the place for the XL.

Formerly known on this forum as @fuchsr -- https://foxrun3d.com/

Napsal : 13/01/2026 5:27 pm
1 lidem se líbí
Stránka 1 / 2
Share: