Hardware, firmware and software help - Prusa3D Forum

Extruder Gear Misalignment

Orion Strayer — Wed, 20 May 2026 17:16:04 +0000

I've been having problems loading and extruding filament on a Prusa XL Multi-Tool due to what appears to be misalignment of the extruder gear. When loading, the filament seems to get squeezed between the gear and the idler door. Then the filament tip usually gets caught on the rim of the hotend tube, producing the notch that you can see in the photo. Even if I manually feed the filament into the hotend tube (which is more challenging than it should be, since the filament needs to bend to get past the extruder gear), the pressure of the filament on the idler door makes the extruder gear skip.

Here is a sketch of what I think is happening:

The extruder gear is further forward than it should be, forcing the filament to curve and pressing it against the idler door.

What I don't know is how this could have happened or how to fix it. I already tried completely disassembling the extruder gear assembly, cleaning the gears, and putting it back together.

(As a side note, this is part of a shared small printing lab for a master's program.)

XL BSOD On Cold start

ReeDoet3D — Tue, 07 Apr 2026 18:21:22 +0000

If I had a nickel for every time this happened, I'd have two nickels, which isn't a lot, but it's weird it happened twice.

No special circumstances; just, powered on the machine, started yelling, hit reset, all works fine.

Wondering what I can do to make this stop.

7e6e456e-img_0653.jpeg

Fan failure and heatbreak thermistor disconnected error

Eric — Tue, 27 Jan 2026 17:18:54 +0000

I just completed the upgrade from 2 to 5 heads following the step-by-step instructions. When I go to reset the calibration I get the error message (heatbreak thermistor disconnected). what could be causing this? The system is also failing the fan test, the fan on the 3rd head does not stop running and the results are showing that heads 3 and 5 do not pass. Any suggestions on resolving these issues?

Looking for Prusa XL assembly tools

alexco323 — Sat, 06 Dec 2025 03:47:44 +0000

Hi - I purchased a used Prusa XL 5 tool off ebay but it didn't have the original assembly tools included with the kit - is there someplace I can purchase this? Thanks in advance for your help.

High flow nozzle, very little flow (15mm3/s)

dimijimi — Tue, 11 Nov 2025 21:20:31 +0000

I bought a "Brass High Flow Prusa Nextruder Nozzle, 0.8mm" directly from E3D. I used the default profile for it on Prusa Slicer. The flow that I can get without the extruder skipping is about 15mm3/s and the nozzle does not seem blocked at.

Has anyone got experience with CHT or HF nozzles on a nextruder, especially if they are bigger than 0.4? What flow are you getting out of it? I am wondering if I'm doing something wrong

Replaced a heatbed tile after an error, now getting an error on another tile

thenixhex311 — Tue, 21 Oct 2025 17:56:25 +0000

Just got this XL (5 toolhead in September). Printer was just sitting there on, after completing a print. Went to start a job, and noticed that the heatbed temp number on the LCD would never get to 60...always just hovered around 55. Cancelled the job and restarted the printer. Booted up, LCD flashed and then restarted with a flashing orange 'heatbed tile 9 damaged or wiring' error message. Reached out to PrintedSolid, and after providing SN/photo of error screen, they sent out a new tile (3rd tile from the left, front row, FYI) and I replaced tile 9. Powered up the printer, and now it's screeching the same error message, but tile 12 (tile directly behind it).

Sitting here waiting for support chat, but figured I'd ask here too just incase anyone else had a similar issue.

Thanks!

Gradual Layer Shift

muddler13 — Tue, 07 Oct 2025 00:08:29 +0000

Looking for recommendations/suggestions for the cause?

Setup:

Prusa XL 5T Firmware 6.26, with PLA,

Cylinder is aprox. 150mm dia.,

Total height of model is 220mm, it never gets that high.

.20 HF noz. using profile that uses the Prusa slicer Speed Profile

I have re-calibrated multiple times, Checked for loose grub screws on the pulleys (all tight). Haven't checked Belt tension with app but they do not appear to be loose. Will check belt tension as soon as current test print which is printing a "Structural" speed.

Thread on nozzle

Steve — Mon, 01 Sep 2025 03:14:30 +0000

I was changing nozzles on my XL the other day, and found that once I had removed the nozzle, it would not screw back in.

Anyway, I ran a 6mm x 1.mm tap through the nozzle thread on the hotend, and the nozzle screwed in just fine. I measured the nozzle beforehand, and that's what the thread was. I have no idea why I had to rethread the hotend, but I did.

Therefore, I can say with certainty that the thread size on the nozzle is 6mm x 1.mm.

I should post this in the other groups who's printers use the Nextruder.

Just so you know.

Steve

Original XL 2 Tools - Issue at the second day with the screen !

Catolard — Fri, 15 Aug 2025 11:22:32 +0000

First of all, I don't understand why I can't have access to the french forum asI'm french ...

It's my first machine and I receive it en wednesday, mount it the same day and start to print withg very good result yesterday.

I finish late yesterday and shut down the machine. All it's ok. Now I star again the machine and after the Bootloader screen which is ok, I have a lot of issue with the screeN; Sometimes ok, but more bad pictures, alternatively black and screen or 50/50, sometimes revert screen .. so the machine is clearly unusable !!!

It appear this morning with the firmware 6.2.5. Thru PRUSA connect I flash again with the latest firmware 6.2.6-alpha+8916 .. exactly same issue.

Thanks.

Catolard

SOFTWARE FIRMWARE NOOB ERRORS

Redshift Z8 — Sun, 06 Jul 2025 09:38:58 +0000

Hello please can you tell me when you going to release an update that fix this incredible machines terrible software. I have multiple xl's and honestly unless you fix this software you will be getting them all back.

What is utterly unacceptable is the fact the machine seems to FORGET there is a extruder loaded onto the machine and then tries to ram it into another docked extruder/head. I mean WHAT IS GOING ON this is a ridicules thing to happen after the machine has been out this long. This is the sort of fault you expect to be fixed in the first weeks of a machines launch.

IF YOU CANCEL A PRINT HALF WAY THROUGH, THEN CLEAN THE BED AND START A NEW PRINT THE MACHINE JUST RAMS WHATEVER HEAD IS ON INTO ANY OTHER HEAD WITH SUCH FORCE IT MIGHT DAMAGE SOMETHING.

Why does it forget its already homed itself on occasions where it should not have. Sometimes the homing simply has a total meltdown another rooky error. The last update lead to loads of people getting extruder not spinning error with a frankly terrible write up on the cause and the solution, that write up frankly made little sense to a majority of people and my 10 year old could have done a better job.

FIX the dam screen on the machines which after a long session just go black. Dont say its a hardware issue because it happens across all 5 xls that i have.

I mean seriously what is going on at prusa to make the flagship machine still have these stupid errors that are so obvious and should have been picked up straight away in testing new version releases.

Come on Prusa get these basic things right !!!!!!!!!!! I would like a response from PRUSA on this errors. No wonder people are buying mass produced bamboos in droves. Its not good enough. If you need to hire people to get this software correct then do it !!!!!!