6.5.3 Firmware for CORE One/+
Summary
- New features and improvements
- Massively speed up MMU filament changes [MMU]
- Updated default input shaper profiles [C1+, C1L]
- Updated translations (beta didn’t have new texts translated)
- Bed LED progress indicator [C1L]
- Tuned parking position during purging [C1, C1+, C1L]
- Vent grille linked to filament preset [C1+, C1L]
- AC supply voltage for the AC controller has been increased [C1L]
- Preload all MMU slots at once [MMU]
- Bootloader update
- Fixes
- Fixed input shaper axis assignment on CoreXY printers
- Fixed layer shifts during high-speed curved moves
- M1704 MMU load test gcode now considers toolmapping [MMU]
- Fixed MMU sending spurious attention reports to Prusa Connect during normal toolchanges [MMU]
- Fixed crash/BSOD on M501 (restore settings) (#4912)
- Fixed gearbox alignment test showing wrong status when skipped
- Fixed chamber fans showing "Auto" instead of "Disabled" when not in use [C1, C1+, C1L]
This is the stable release of firmware 6.5.3 for the Prusa CORE One L, CORE One+, CORE One, MK4S, MK4, MK3.9S, MK3.9, MK3.5S and MK3.5 bringing targeted stability improvements and fixes.
Massively speed up MMU filament changes [MMU]
A series of improvements have been implemented that massively speed up MMU filament changes by up to 9 seconds. Some changes in the MMU firmware were required as well, so it is necessary to flash a https://github.com/prusa3d/Prusa-Firmware-MMU/releases/tag/v3.0.4&sa=D&source=docs&ust=1773131390056718&usg=AOvVaw1-toj-3WO51cdOwPWjwVd X" rel="nofollow">new 3.0.4 firmware to your MMU unit.
The improvements include:
- Parallelized unloading filament from the nozzle and idler engaging.
- The printer does not wait for the final idler disengagement to finish to continue printing.
- Parallelized selector and idler movement.
- FeedingToFinda phase now obeys PulleySlowFeedrate with higher value.
- Optimized idler selection mechanism during filament change.
For more information about MMU improvements and the CORE One L MMU3, check out our blog post.
Updated default input shaper profiles [C1+, C1L]
In 6.5.3-beta, we’ve fixed a bug in the input shaper configuration of our CoreXY printers. If you haven’t changed your input shaper settings, the new values will update automatically.
NOTE: If you have CORE One L or an accelerometer accessory, we recommend re-running your input shaper calibration.
If you modified these values in the past we recommend resetting your input shaper profiles to defaults using the Settings → Input Shaper → Restore Defaults.
Bed LED progress indicator [C1L]
The CORE One L bed LED indicator now shows the progress of your print, starting from the left and gradually changing from white to blue.
Tuned parking position during purging [C1, C1+, C1L]
The parking position on CORE One and CORE One L has been adjusted so that purged filament flows unobstructed to the bottom, reducing potential debris on the print bed.
Vent grille linked to filament preset [C1+, C1L]
The vent grille now automatically opens or closes based on the target chamber temperature set in the active filament preset. This ensures optimal thermal conditions during printing.
AC supply voltage for the AC controller has been increased [C1L]
Based on user feedback, we have increased the maximum supported AC supply voltage for the AC controller to 264 V.
Preload all MMU slots at once [MMU]
The new menu item Filament MMU - Preload All now asks for the filament type only once and applies it to all slots. This is handy when you want to load, for example, five PLA filaments.
Bootloader update
The bootloader has been updated to version 2.6.0. This creates the necessary foundation for the upcoming INDX upgrade.
Fixed input shaper axis assignment on CoreXY printers
The input shaper X and Y axis parameters were swapped on CoreXY printers, meaning the shaper configured for X was actually applied to Y, and vice versa. This also prevented users from disabling input shaping on only one axis. Both issues are now resolved.
Fixed layer shifts during high-speed curved moves
Layer shifts could occur during high-speed printing with curved moves. The motion system has been improved to address the issue.
Note: Please be aware that not all layer shifts have been caused by this issue.
Release notes:
https://github.com/prusa3d/Prusa-Firmware-Buddy/releases/tag/v6.5.3
RE: 6.5.3 Firmware for CORE One/+
Should I rerun Input shaper and phase stepper calibration after I did it running the 6.5.3. RC firmware ?
RE: 6.5.3 Firmware for CORE One/+
I would do it. Once with version 6.4 and once with the new version—as a point of comparison.
Should I rerun Input shaper and phase stepper calibration after I did it running the 6.5.3. RC firmware ?
Mods for Core One: Core One HT 450 degrees, Comfortable display , Very fast print start and Reducing noises
Mods for Prusa XL: Very fast print start
RE: 6.5.3 Firmware for CORE One/+
Still don't know why they are not listing the lower chamber temps alarm thresholds and the 55° clamp in the release notes.
RE: 6.5.3 Firmware for CORE One/+
Here's a summary of the changes between v6.4.0 and v6.5.3 (250 commits):
Core One (C1/C1L) Specific
- Chamber vents: Auto/manual switching of vent mechanism, avoid vent mechanism during homing, open/close vent grille based on filament preset chamber target temp
- Parking positions: Tuned for both C1 and C1L
- Bed LEDs: Added progress indication on C1L bed LEDs
- Input shaper: New IS defaults for C1 and C1L
- AC controller: Bumped through multiple versions (v0.0.2 → v0.0.8)
- Chamber temp: Increased max selectable chamber temp to 60°C
- QR code fix: Fixed truncated door sensor calibration QR code on C1LCommon / All Printers
Printing & Motion
- Better planner ↔ Move
- ISR synchronization with critical sections
- Phase stepping optimizations (bigger buffers, stack usage, calibration improvements)Segmented probe lift moves
- Junction Deviation enabled (iX)
- Homing improvements (bump moves, sensitivity calibration fix)
MMU (Multi-Material)
- 10x faster communication rate (MMU over Modbus)
- Parallel idler disengagement during nozzle push
- Smarter unload (as soon as filament sensor turns off)
- Better error handling (avoid repeated parking, allow toolmapping)
- Updated to MMU FW 3.0.4
Filament & Sensors
- Filament sensor selftest no longer requires removing filament first
- Improved auto-retract system with ramming sequence migration
- Fixed filament runout beeping
- Fixed nullptr access in filament sensors
UI & UX
- Added reusable "Happy Printing!" message (shown once, not during FW upgrade)
- Touch enabled by default
- Chamber fans shown as disabled when not used (cleaner UI)
- Reworded Nextruder maintenance warning
- Reworded INPUT_OVERCURRENT error
Cooling & Fans
- Bed fan and PSU fan error checking added (then reverted during print)
- Fixed fan RPM min/max truncation in getters
- Cooling recovery temperature hysteresis fix
Nozzle Cleaning
- Unified cleaning sequences across printers
- Less strict probe analysis to reduce false "cleaning failed" errors
- Cooldown temp set before user confirmation
Stability & Fixes
- Fixed BSOD on M501, during probing, and in debug builds
- Fixed media prefetch errors (wrong error on disconnected drive, valid_for_print logic)
- Fixed crash in hwio_safe_state()
- Fixed FSM not being destroyed
- Reduced excessive logging in pause
- GCC updated to 13.3
Selftest
- Fixed passing axis/heater/Z-alignment tests after reset
- Removed unnecessary bed preheating
- Loadcell selftest uses mapi::park
Connectivity
- Network setup marked as done by default on non-ESP printers
- Connect telemetry interval increases
- Log forwarding from XBuddy extension
- Don't send BSOD error codes to Connect (only dump message)
RE: 6.5.3 Firmware for CORE One/+
Installed, recalibrated and ran a test part. I got the exact same shaper values and type as with the RC version. Probably the same micro stepping, but they don't display anything to compare. Test part looks about the same, but I need to print more parts.
IMO, they should change the default shaper and stepping values as my numbers are similar to what others have seen (about 46 Hz) and the defaults seem a ways off. I can't believe all Core Ones are that much different unless it's the solidity of the table it's on. Accelerometer calibration takes my printer from quite audible to very quiet, often below the level of the fans.
RE: 6.5.3 Firmware for CORE One/+
That’s a question I’ve been asking myself too, my values are also very close together.
I adjusted the belt tension before.
Apart from that, the printer runs very quietly, only occasionally does it pick up a frequency that causes it to resonate.
It would also be interesting to know when junction deviation will be adopted into the C1 slicer profile, after all, this has been announced for some time now.
RE: 6.5.3 Firmware for CORE One/+
After I installed 6.5.3 I ran the input shaper, and I got this error: X axis frequency too low tighten the belt. I then checked that the gantry is squared and checked that my belts were correctly adjusted, ran the shaper again with the same result, tightened both my belts 1/8 turn and ran the shaper again X 38 and Y 43 Then I run the belt adjustment and my belts are too tight and need to be loosened 1/8 turn, I did this back and forth a couple of times with the same result and find this strange because I have not had this problem before
RE: 6.5.3 Firmware for CORE One/+
CoreOne/+, 6.5.3 loaded. I have an MMU, the MMU DID NOT update and now shows it is incompatible. Now I can't use my MMU. Github #5202 Seeing If I can revert to 6.4.0
RE: 6.5.3 Firmware for CORE One/+
CoreOne/+, 6.5.3 loaded. I have an MMU, the MMU DID NOT update and now shows it is incompatible. Now I can't use my MMU. Github #5202 Seeing If I can revert to 6.4.0
Hi, I had the same issue; I've connected a usb cable directly to the MMU3 and flashed the "MMU3_FW3.0.4+936.hex" using PrusaSlicer. After flashing the MMU3 restarted by itself and worked normally.
RE:
In the description of the printer's FW 6.5.3 it is clearly written that the MMU needs the new FW 3.0.4! The link here doesn't work, visit the MMU3 section of this forum.
RE: 6.5.3 Firmware for CORE One/+
The link here doesn't work, visit the MMU3 section of this forum.
Mods for Core One: Core One HT 450 degrees, Comfortable display , Very fast print start and Reducing noises
Mods for Prusa XL: Very fast print start
RE: 6.5.3 Firmware for CORE One/+
Am I the only one with a Core One and MMU3 who has the issue where the motor pulley doesn’t activate to pull the filament back and have to press the retry button 20 times or more before the command finally reaches the motor to retract the filament? Forget saving 9 seconds per color change I’m spending an extra 9 minutes for every change.
RE: 6.5.3 Firmware for CORE One/+
I guess we have gone backwards according to the Github answers. I was relying on past promises about MMU3 updates. MMU3 must again be flashed independently. Hopefully others can see this and avoid bricking their system.
The link missing from the release notes on how to install MMU3 Firmware.
Now to find the cable somewhere, update slicer to include the printer drivers and do the update.
Thanks everyone.
RE: 6.5.3 Firmware for CORE One/+
did someone already tried to cancel an object in a multiobject print with this new FW?
RE:
There is also a slicer update for the new software. Does this mean we need to NOT use all the old print files for the Coreone and MMU3? New ones are needed?
RE:
CoreOne/+, 6.5.3 loaded. I have an MMU, the MMU DID NOT update and now shows it is incompatible. Now I can't use my MMU. Github #5202 Seeing If I can revert to 6.4.0
Read description that Jan wrote in first post, that's why it's there: (and it's BOLDED)
Some changes in the MMU firmware were required as well, so it is necessary to flash a https://github.com/prusa3d/Prusa-Firmware-MMU/releases/tag/v3.0.4&sa=D&source=docs&ust=1773131390056718&usg=AOvVaw1-toj-3WO51cdOwPWjwVd X" rel="nofollow">new 3.0.4 firmware to your MMU unit.
Yes, the link doesn't work if you click on it, but you can see where it's broken (at X), so it's best to visit support page for MMU3.
RE: 6.5.3 Firmware for CORE One/+
where did you see a slicer update?
There is also a slicer update for the new software. ...
RE: 6.5.3 Firmware for CORE One/+
There is also a slicer update for the new software. Does this mean we need to NOT use all the old print files for the Coreone and MMU3? New ones are needed?
Oh, I see—you must be referring to the update of the “configuration file.”
Mods for Core One: Core One HT 450 degrees, Comfortable display , Very fast print start and Reducing noises
Mods for Prusa XL: Very fast print start
RE:
where did you see a slicer update?
There is also a slicer update for the new software. ...
Yes, it is a configuration update. My coreone+ and MMU3 are working and updated. I updated the MMU3 3.0.4 firmware first, then the Coreone+ to 6.5.3. Opened up the Prusaslicer and did the configuration update for the new settings.
configuration update 2.4.1116. 3. 2026 Added profiles for Prusa Signature Oak.Added profiles for CORE One L MMU3.Updated MMU parameters for MK3.9/MK4/C1 family printers (start g-code and filament unload speeds).Reduced max. volumetric speed for Fillamentum Flexfill 98A (MK4/C1/XL).
Seeing the MMU parameter change for all systems I am reprocessing MMU based print files through the Prusaslicer after the configuration update.
I have successfully run a multicolor print with no problems.
Preload to MMU has some changes. See the MMU, firmware 3.0.4 discussion for some details.