6.0.3 Firmware for Original Prusa MK4, MK3.9, MK3.5, MINI & XL

Summary

• Interim solution of USB disconnect issues (MK4, MK3.9, MK3.5, XL)
• PINDA off-bed probing repaired (MK3.5)
• Screenshot procedure fix (MINI)

Interim solution of USB disconnect issues (MK4, MK3.9, MK3.5, XL)

The developers have thoroughly reviewed the part of the firmware responsible for unexpected USB disconnects, which lead to print interruptions that cannot be resumed. As a quick hotfix, we have added the option to continue printing after this interruption.
However, we will continue to seek a definitive solution to this problem.

PINDA off-bed probing repaired (MK3.5)

Moved bed leveling probing points to avoid probing measurements out of the heatbed area. This issue was reported on GitHub as #3851.

Screenshot procedure fix (MINI)

Fixed an issue where the screenshot procedure ended with a blue screen of death (BSOD).

Full Changelog: v6.0.2...v6.0.3

6.0.2 Firmware for Original Prusa MK4, MK3.9, MK3.5, MINI & XL

Summary

• Original Prusa XL Enclosure functions (XL)
• Improvements by Prusa community

This is a stable firmware release 6.0.2 with Original Prusa XL Enclosure and its additional functions. It also fixes issues discovered during testing, as well as those reported by the Prusa community.

Original Prusa XL Enclosure functions (XL)

The XL Enclosure is designed to be seamlessly integrated with the rest of the printer. Not just the physical parts, but also the software, a new menu becomes available on the LCD touchscreen called Enclosure. Because the Enclosure is directly connected to the mainboard of the printer, you can configure a number of useful features. You can set up the filtration performance and even post-print filtration duration (e.g. when you print from materials such as ASA or PCCF) so that the system runs for additional time to filter out all particles produced during the print job. For more information, read this article.

Enabling the XL Enclosure in the menu
You can enable the XL Enclosure by going to Control -> Enclosure (Enable) on the printer. Then, run a fan connection test to verify that everything works. After that, you will see the Enclosure menu.

Features

• Filtration When you have enabled Enclosure and Print Filtration, the fan will operate at 80% of RPM. You can adjust the filtration performance in the menu (from 50% to 100%) during a running print job.

• Post Print Filtration You can also enable Post Print Filtration in Control -> Enclosure -> Manual Settings -> Post Print Filtration. When certain filaments (ASA, ABS, PC, FLEX, HIPS, PP) are detected in the G-code, the filtration will run for an additional 10 minutes to filter out all particles produced during printing. You can adjust the Post Print Filtration setting from 1 to 10 minutes..
  Note: PLA/PETG prints do not require post-print filtration.

• MCU Cooling The MCU checks the temperatures of the electronic boards on the Original Prusa XL.
  MCU Cooling has the highest priority and activates automatically (fan at 100%) when the enclosure is powered on. MCU cooling is activated when temperatures of any electronic board exceed 80°C and stops cooling at 75°C, regardless of whether printing is in progress. This is to protect internal electronics from overheating and to extend their lifespan.

• Temperature Display You can display the temperature inside the enclosure in the footer by going to Settings -> User Interface -> Footer. The temperature value is derived from the current or first tool board temperature. The temperature will be displayed 5 minutes after the start of printing. This delay is due to the need for temperature stabilization inside the XL Enclosure. The temperature will reset to “–” after the print is complete.

• Filter Expiration Tracking The enclosure tracks the active filtration time (not print time). After 500 hours, a dialog alerts the user that the filter will expire in 100 hours (the estimated lifespan is 600 hours of runtime). The dialog will let you choose from [IGNORE] - which will remind you before every print to change the HEPA filter, [POSTPONE] - which will postpone the dialog for 5 days, and [DONE] - which means that the HEPA filter has been changed and will restart the filter counter. After 600 hours, a dialog suggests changing the filter with a link to prusa.io/xl-filter.

• Fan Error Check will alert the user to check the fan connection and cleanliness if the fan isn't spinning as it should.

• Fan Connection Test will check if the fan is properly connected. This test runs whether you enable the enclosure from the menu or start the print.

Improvements by Prusa community

• Community translation correction #4002
• Community translation correction #3614

Community contributors @bkerler @hawwwran

Full Changelog: v6.0.1...v6.0.2

6.0.1 Firmware for Original Prusa MK4, MK3.9, MK3.5, MINI & XL

Summary

• Japanese language support (MK4, MK3.9, MK3.5, XL)
• Phase stepping fixes (XL)
• Nozzle cleaning repaired (MK4, MK3.9, XL)
• Acceleration limit restored (MK4, MK3.9, MINI)
• Stealth mode corrected (MK4, MK3.9, MK3.5, XL)

This is a stable firmware release 6.0.1 that adds one more language and fixes some issues discovered during testing, as well as reported by the Prusa community.

Japanese language support (MK4, MK3.9, MK3.5, XL)

Together with our team in Japan, we have translated the entire Buddy firmware into Japanese. The firmware will be utilizing Katakana. While implementing all the characters we encountered some interesting challenges. For example, Latin characters are typically more rectangular (taller than wider), whereas Katakana characters are closer to square in shape. This required some adjustments in the firmware.

The Japanese language is currently available for most of our printers on the Buddy platform, the only exception is MINI/MINI+ which requires further optimizations. We expect support for the MINI in the upcoming firmware release.

To our Prusa community in Japan ハッピー・プリンティング！

Phase stepping fixes (XL)

The developers have thoroughly reviewed the part of the firmware responsible for phase stepping and identified some edge cases occurring during operations such as homing, layer changes, filament changes, and tool changes on the XL.

Now, these specific edge cases are fixed and there should no longer be any skipped layers after the G-code M600 (filament change), and the XL tools should always be parked correctly.

Nozzle cleaning repaired (MK4, MK3.9, XL)

The nozzle cleaning process sometimes resulted in an error “Nozzle cleaning failed” due to a bug introduced in firmware 6.0.0. This bug caused the load cell buffer to "underrun," leading to an incorrect calculation of the distance between the tip of the nozzle and the heatbed. This error has now been fixed, and the nozzle cleaning feature should perform correctly again.

Acceleration limit restored (MK4, MK3.9, MINI)

Firmware 6.0.0 accidentally lowered the HW limit for acceleration and jerk in Normal mode, this release returns the limit to its original value.

Stealth mode corrected (MK4, MK3.9, MK3.5, XL)

In some scenarios, the firmware was not able to switch back to the Normal mode, this is now fixed.

6.0.0 Firmware for Original Prusa XL

Summary

• Phase Stepping & Calibration
• Touch support
• Stuck filament detection
• Stealth mode
• Time Zone settings updated
• Filament Sensor Options
• RGB Side Strip Dimming
• XL Enclosure support
• Improvements by Prusa community
• Bug fixes
• Known issues

This is the stable release of firmware 6.0.0 with Phase Stepping for the Original Prusa XL, featuring major changes and improvements. This release is recommended to all users.

If you are not using alpha/beta releases, upgrading from previous versions will give you plenty of new options and features to dig into. We’re covering everything important in these release notes, including changes introduced in the previous release candidates (RC).

Previous releases:

• 6.0.0-RC3
• 6.0.0-alpha

Phase Stepping & Calibration

Overview

In the early stages of development, we selected the Trinamic 2130 drivers to have the options to further improve the stepping of motors in the XL. As a result of this development, we see improvements in print quality and a reduction in printer noise. Due to the natural variance in stepper motor manufacturing, each motor responds uniquely to driver signals, causing visible fine artifacts (VFAs) and noise. Phase Stepping customizes the drive signal for each motor, addressing these discrepancies by reducing VFAs and audible noise, thereby enhancing the printing experience.

How it works

The printer will move the print head (in the case of the Multi-Tool it will select the first print head) to the middle of the bed and start to move the tool diagonally for the X and Y axes at different speeds - while collecting data from the accelerometer located on the Dwarf board inside the Nextruder. The goal is to measure the characteristics of the motors and store these settings

How to Perform the Calibration

After updating the Firmware navigate to Menu - Control - Calibrations & Tests - Phase Stepping Calibration. The calibration shouldn't run on multiple printers side by side simultaneously. The neighboring printer performing similar motions may affect the measurement.

Phase Stepping and crash detection

Currently, if Phase Stepping is enabled, crash detection is disabled. This is due to technical reasons. Developers are investigating whether these two features can work together.

Touch support

This release extends support for the XL. For now, you must manually enable the touch feature from the menu. Navigate to Settings -> User interface -> Touch.

With the touch enabled you'll be able to control the majority of items on the screen. You can swipe your finger up and down to scroll through the menu. Swiping left or right (depending on your preference) takes you one step back in the menu hierarchy.

There are some exceptions where the knob must be used, such as when setting the target temperature manually or while moving with any of the axes.

Tip: If you experience issues with the touch, please enable the Touch Sig Workaround option in the menu. Navigate to Settings -> User Interface -> Touch Sig Workaround

Stuck filament detection

Starting from this release, the loadcell sensor in the Nextruder will not only be used for the mesh bed leveling but also for detecting whether the filament is stuck and not moving (e.g. when the nozzle is clogged).

When certain conditions are met, the print will be paused, filament unloaded and the system will notify you that the filament was most likely stuck. Once you check the filament, reload it back to the Nextruder, and then you can resume the print job.

It is important to note that detecting stuck filament is possible only inside the Nextruder, as pressure builds up from the nozzle to the upper part of the Nextruder. However, if your filament is tangled on the spool, there will be no internal pressure, just outside tension, which the loadcell won't be able to recognize.

Stealth mode

Similar to the MK3 family, we are introducing Stealth mode, which will make your printer even quieter. This can be useful for example for overnight prints. You can switch between Normal and Stealth mode even during the print. Keep in mind that the mode will be activated once several G-code commands in the buffer (printer memory) are processed.

Once the Stealth mode is enabled, the firmware sets a limit to acceleration, feed rate, and jerk. Setting a cap on these parameters will lower the noise. While this reduces noise, it also affects the overall printing time.

In addition to Stealth mode, we are also adding support for the M73 G-code. You can find more information in this article. To apply the G-code M73 properly, you have to reslice or edit your existing G-codes, make sure you are using PrusaSlicer 2.7.4 and the latest print profiles.

Time Zone settings updated

This release increases the timezone hour offset range up to +14 hours and also introduces a timezone minutes option to select a timezone offset in minutes (0 min, 30 min, and 45 min).

This addresses issues #3550, #1779 and #3141.

Filament Sensor Options

The filament sensor function now lets you choose which filament sensor to switch ON or OFF. This allows you to control the Side filament sensor and the Tool filament sensor individually or toggle all of them simultaneously. Navigate to Settings -> Filament sensors

RGB Side Strip Dimming

Starting this release you can enable or disable dimming for the LED side strip.
Go to Menu - Settings - User Interface - RGB Side Strip Dimming

XL Enclosure support

This firmware lays the groundwork for the upcoming XL Enclosure release, featuring the addition of the 'Enclosure' item in the printer's menu. For now, this feature is disabled, however, once you connect your XL Enclosure, this item will become fully functional.

Improvements by the Prusa community

Once again, thanks to the active members of the community, we could improve the firmware with two new pull-request (#3766, and #3779). Kudos to the user @bkerler!

Bug fixes

• Tool Offset Calibration, which would cause in some cases a red screen or would either fail or not complete is now working properly.
• Opening the Input Shaper (IS) menu was disabled by accident in the previous release, although the IS was still functioning. This restores the user's ability to open the menu and view the currently applied filters and frequencies. All values are currently set automatically, with manual adjustment planned for future releases.
• During the filament loading procedure, the “STOP” button wasn't working properly. This is now fixed.

Known issues

• As you scroll through the print menu, the selection field may not be displayed correctly.
• Sometimes, when you run another print, you may get a nozzle cleaning failed message #3818. Restarting the printer should solve this issue.
• When using WPA3/WPA2 Transition mode, your printer may not connect to Wi-Fi. While this issue often stems from certain router configurations, we are actively seeking solutions to bypass these limitations and improve connectivity #3864.

6.0.0 Firmware for Original Prusa MK4, MK3.9, MK3.5 & MINI

Summary

• Touch support (MK4/MK3.9/MK3.5)
• Stuck filament detection (MK4/MK3.9)
• Stealth mode (MK4/MK3.9/MK3.5/MINI)
• MMU3 support for the (MK4/MK3.9/MK3.5)
• MMU3 firmware auto-update (MK4/MK3.9/MK3.5)
• Cold Pull (MK4/MK3.9)
• Time Zone settings updated (MK4/MK3.9/MK3.5/MINI)
• Bed Level Correction (MK3.5, MINI)
• Revised Control menu (MINI)
• MCU temperature (MINI)
• Improvements by the Prusa community
• Bug fixes
• Known issues

This is the stable release of firmware 6.0.0 featuring major changes and improvements. This release is recommended to all owners of:

• Original Prusa MK4
• Original Prusa MK3.9
• Original Prusa MK3.5
• Original Prusa MK4 & MMU3
• Original Prusa MK3.9 & MMU3
• Original Prusa MK3.5 & MMU3
• Original Prusa MINI & MINI+

Note: Original Prusa XL was released earlier today as a release candidate. Read the full XL changelog here. A stable release is expected soon.

If you are not using alpha/beta releases, upgrading from previous versions will give you plenty of new options and features to dig into. We’re covering everything important in these release notes, including changes introduced in the previous release candidates (RC).

Previous releases:

• 6.0.0-RC1
• 6.0.0-RC2

Touch support (MK4/MK3.9/MK3.5)

The touchscreen has been part of MK4/MK3.9/MK3.5 from the very beginning of the production (which is also true XL). We wanted to make the touch controls a worthy and useful addition to the current control scheme and took our time to do it right. Also, during the development phase, prior to the official launch, we encountered a couple of challenges. Resolving them required extensive collaboration with our suppliers, multiple rounds of testing, and numerous adjustments to the firmware which added to the total development time.

Please note you have to manually enable the touch feature from the menu. Navigate to Settings -> User interface -> Touch.

With the touch enabled you'll be able to control the majority of items on the screen. You can swipe your finger up and down to scroll through the menus. Swiping left or right (depending on your preference) takes you one step back in the menu hierarchy.

There are some exceptions where the knob must be used, such as when setting the target temperature manually or while moving with any of the axes.

Tip: If you experience issues with the touch, please enable the Touch Sig Workaround option in the menu. Navigate to Settings -> User Interface -> Touch Sig Workaround

Note: MINI and MINI+ do not have a touch layer integrated into the screen, therefore adding touch support via a firmware update is not possible.

Stuck filament detection (MK4/MK3.9)

Starting from this release, the loadcell sensor in the Nextruder will not only be used for the mesh bed leveling but also for detecting whether the filament is stuck and not moving (e.g. when the nozzle is clogged).

When certain conditions are met, the print will be paused, filament unloaded and the system will notify you that the filament was most likely stuck. Once you check the filament, reload it back to the Nextruder, and then you can resume the print job.

It is important to note that detecting stuck filament is possible only inside the Nextruder, as pressure builds up from the nozzle to the upper part of the Nextruder. However, if your filament is tangled on the spool, there will be no internal pressure, just outside tension, which the loadcell won't be able to recognize.

Note: Stuck filament detection won't be possible on MK3.5 and MINI/MINI+ as they aren't equipped with the loadcell sensor.

Stealth mode (MK4/MK3.9/MK3.5/MINI)

Similar to the MK3 family, we are introducing Stealth mode, which will make your printer even quieter. This can be useful for example for overnight prints. You can switch between Normal and Stealth mode even during the print. Keep in mind that the mode will be activated once several G-code commands in the buffer (printer memory) are processed.

Once the Stealth mode is enabled, the firmware sets a limit to acceleration, feedrate, and jerk values. Setting a cap on these parameters will lower the noise. While this reduces noise, it also affects the overall printing time.

In addition to Stealth mode, we are also adding support for the M73 G-code. You can find more information in this article. To apply the G-code M73 properly, you have to reslice or edit your existing G-codes, make sure you are using PrusaSlicer 2.7.4 and the latest print profiles.

MMU3 support for the (MK4/MK3.9/MK3.5)

The firmware 6.0.0 unites support for the MK4/MK3.9 (introduced in 6.0.0-RC1) and MK3.5 (introduced in 5.2.1). It is important to note that each printer requires its own hardware upgrades as well as firmware versions to function properly with the MMU3.

• To learn more about MK4/MK3.9 MMU3 setup, please visit: 6.0.0-RC1 release notes
• To learn more about MK3.5 MMU3 setup, please visit: 5.2.1 release notes

MMU firmware compatibility (file is included below):

• FW3.0.3+896.hex - compatible with MK4, MK3.9, MK3.5

MMU3 firmware auto-update (MK4/MK3.9/MK3.5)

This firmware sets a base for the upcoming feature allowing you to update the MMU3 unit firmware from the printer. Currently, you have to connect a Micro USB cable to the control board in the MMU3 and update the firmware manually using PrusaSlicer.

Starting firmware 6.0.0 the printers with xBuddy mainboards (MK4, MK3.9 and MK3.5) will be soon able to flash the MMU3 unit automatically. The MMU3 firmware will be from now on always a part of the printer's firmware, so once you flash the printer’s firmware, the MMU will be updated as well.

However, to enable this functionality, you have to update the bootloader in the MMU3 unit's control board. This is a significant change to the entire MMU ecosystem and we are currently running extensive tests covering all possible scenarios to ensure a flawless experience.

These tests are expected to be finished soon. The new bootloader will be then flashed to all MMU3 leaving the factory and also uploaded to GitHub and Help.prusa3d.com for all existing MMU3 users.

Note: This feature is not supported on the MK3S+. If you want to enjoy the MMU3 auto-update feature, consider upgrading your printer to the MK3.5, M3.9 or MK4. Upgrade packages are available at the Prusa e-shop.

Cold Pull (MK4/MK3.9)

The Cold Pull method is a popular method used for unclogging or cleaning your extruder. Starting from this release, you can take advantage of a new feature that will guide you through the entire process using a step-by-step Wizard and provide assistance.

Note: Support for other Prusa printers is planned in a future release as soon as their implementation of the cold pull method is ready.

Time Zone settings updated (MK4/MK3.9/MK3.5/MINI)

This release increases the timezone hour offset range up to +14 hours and also introduces a timezone minutes option to select a timezone offset in minutes (0 min, 30 min, and 45 min).

This addresses issues #3550, #1779 and #3141.

Bed Level Correction (MK3.5, MINI)

This feature, originally introduced on the Original Prusa MK3 as an addition to the Mesh Bed Leveling (MBL), allowed experienced users to further compensate for any imperfections on the heatbed. The bed level correction gathers user data on how to adjust Z height in four directions around the plate (front, left, back, right) and then changes mesh bed leveling values through linear interpolation.

In most cases, this manual correction is unnecessary as MBL will handle compensation automatically. To adjust settings visit Control -> Bed Level Correction.

Revised Control menu (MINI)

To unite the user experience across all printers with the Buddy firmware, this release brings a revised Control menu on the MINI, where all tests were moved into the Calibrations & Tests submenu together with First Layer Calibration.

MCU temperature (MINI)

The MCU temperature is now available in the Sensor info menu.

Improvements by the Prusa community

Once again, thanks to the active members of the community, we have improved the firmware with two new pull requests (#3766, and #3779). Kudos to the user @bkerler!

Bug fixes

• A bug #3890 in the firmware 5.2.2 causing a shorter loading sequence into the MK3.5 MMU3 setup is now fixed.
• The previous release was missing an option to “Preload All” five filaments into the MMU unit and allowed to preload only one filament at a time. This is now fixed.
• Opening the Input Shaper (IS) menu was disabled by accident in the previous release, although the IS was still functioning. This restores the user's ability to open the menu and view the currently applied filters and frequencies. All values are currently set automatically, with manual adjustment planned for future releases.
• During the filament loa...

6.0.0-RC3 Firmware for Original Prusa XL

Summary

• Phase Stepping & Calibration
• Touch support
• Stuck filament detection
• Stealth mode
• Time Zone settings updated
• Filament Sensor Options
• RGB Side Strip Dimming
• XL Enclosure support
• Improvements by Prusa community
• Bug fixes

This is a release candidate for the Original Prusa XL from the firmware branch 6.0.0.

Phase Stepping & Calibration

Overview

In the early stages of development, we selected the Trinamic 2130 drivers to have the options to further improve the stepping of motors in the XL. As a result of this development, we see improvements in print quality and a reduction in printer noise. Due to the natural variance in stepper motor manufacturing, each motor responds uniquely to driver signals, causing visible fine artifacts (VFAs) and noise. Phase Stepping customizes the drive signal for each motor, addressing these discrepancies by reducing VFAs and audible noise, thereby enhancing the printing experience.

How it works

The printer will move the print head (in the case of the Multi-Tool it will select the first print head) to the middle of the bed and start to move the tool diagonally for the X and Y axes at different speeds - while collecting data from the accelerometer located on the Dwarf board inside the Nextruder. The goal is to measure the characteristics of the motors and store these settings

How to Perform the Calibration

After updating the Firmware navigate to Menu - Control - Calibrations & Tests - Phase Stepping Calibration. The calibration shouldn't run on multiple printers side by side simultaneously. The neighboring printer performing similar motions may affect the measurement.

Phase Stepping and crash detection

Currently, if Phase Stepping is enabled, crash detection is disabled. This is due to technical reasons. Developers are investigating whether these two features can work together.

Touch support

Touch is already supported for the MK4/MK3.9/MK3.5, This release extends support for the XL. For now, you must manually enable the touch feature from the menu. Navigate to Settings -> User interface -> Touch.

With the touch enabled you'll be able to control the majority of items on the screen. You can swipe your finger up and down to scroll through the menu. Swiping left or right (depending on your preference) takes you one step back in the menu hierarchy.

There are some exceptions where the knob must be used, such as when setting the target temperature manually or while moving with any of the axes.

Tip: If you experience issues with the touch, please enable the Touch Sig Workaround option in the menu. Navigate to Settings -> User Interface -> Touch Sig Workaround

Stuck filament detection

Starting from this release, the loadcell sensor in the Nextruder will not only be used for the mesh bed leveling but also for detecting whether the filament is stuck and not moving (e.g. when the nozzle is clogged).

When certain conditions are met, the print will be paused, filament unloaded and the system will notify you that the filament was most likely stuck. Once you check the filament, reload it back to the Nextruder, and then you can resume the print job.

It is important to note that detecting stuck filament is possible only inside the Nextruder, as pressure builds up from the nozzle to the upper part of the Nextruder. However, if your filament is tangled on the spool, there will be no internal pressure, just outside tension, which the loadcell won't be able to recognize.

Stealth mode

Similar to the MK3 family, we are introducing Stealth mode, which will make your printer even quieter. This can be useful for example for overnight prints. You can switch between Normal and Stealth mode even during the print. Keep in mind that the mode will be activated once several G-code commands in the buffer (printer memory) are processed.

Once the Stealth mode is enabled, the firmware sets a limit to acceleration, feed rate, and jerk. Setting a cap on these parameters will lower the noise. While this reduces noise, it also affects the overall printing time.

In addition to Stealth mode, we are also adding support for the M73 G-code. You can find more information in this article. To apply the G-code M73 properly, you have to reslice or edit your existing G-codes, make sure you are using PrusaSlicer 2.7.4 and the latest print profiles.

Time Zone settings updated

This release increases the timezone hour offset range up to +14 hours and also introduces a timezone minutes option to select a timezone offset in minutes (0 min, 30 min, and 45 min).

This addresses issues #3550, #1779 and #3141.

Filament Sensor Options

The filament sensor function now lets you choose which filament sensor to switch ON or OFF. This allows you to control the Side filament sensor and the Tool filament sensor individually or toggle all of them simultaneously. Navigate to Settings -> Filament sensors

RGB Side Strip Dimming

Starting this release you can enable or disable dimming for the LED side strip.
Go to Menu - Settings - User Interface - RGB Side Strip Dimming

XL Enclosure support

This firmware lays the groundwork for the upcoming XL Enclosure release, featuring the addition of the 'Enclosure' item in the printer's menu. For now, this feature is disabled, however, once you connect your XL Enclosure, this item will become fully functional.

Improvements by the Prusa community

Once again, thanks to the active members of the community, we could improve the firmware with two new pull-request (#3766, and #3779). Kudos to the user @bkerler!

Bug fixes

• Tool Offset Calibration, which would cause in some cases a red screen or would either fail or not complete is now working properly.
• Opening the Input Shaper (IS) menu was disabled by accident in the previous release, although the IS was still functioning. This restores the user's ability to open the menu and view the currently applied filters and frequencies. All values are currently set automatically, with manual adjustment planned for future releases.
• During the filament loading procedure, the “STOP” button wasn't working properly. This is now fixed.

6.0.0-RC2 Firmware for Original Prusa MK4, MK3.9, MK3.5 & MINI

Summary

• Touch support (MK4, MK3.9 and MK3.5)
• Stealth mode (MK4, MK3.9, MK3.5 and MINI)
• Time Zone settings updated (MK4, MK3.9, MK3.5 and MINI)
• Bed Level Correction (MK3.5, MINI)
• Revised menu (MINI)
• MCU temperature (MINI)
• MMU3 unit firmware auto-update
• Bug fixes

This is a second release candidate for the upcoming firmware 6.0.0. This release includes firmware files for the MK4, MK3.9, MK3.5 and MINI/MINI+. The XL firmware is not part of today's release as it is currently undergoing final re-testing and is planned to be released soon after.

Make sure you have also read the release notes of the firmware 6.0.0-RC1 as the improvements are also part of this RC2 release.

Touch support (MK4, MK3.9 and MK3.5)

Touch is already supported for the MK4/MK3.9 (see the previous release notes for the 6.0.0-RC1). This release extends support for the MK3.5. For now, you must manually enable the touch feature from the menu. Navigate to Settings -> User interface -> Touch.

With the touch enabled you'll be able to control the majority of items on the screen. You can swipe your finger up and down to scroll through the menu. Swiping left or right (depending on your preference) takes you one step back in the menu hierarchy.

There are some exceptions where the knob must be used, such as when setting the target temperature manually or while moving with any of the axes.

Note: MINI and MINI+ do not have a touch layer integrated into the screen, therefore adding touch support via a firmware update is not possible. Support for the XL will be added in the upcoming release.

Stealth mode (MK4, MK3.9, MK3.5 and MINI)

Stealth mode is already supported for the MK4/MK3.9 (see the previous release notes for the 6.0.0-RC1). This release extends support for the MK3.5 and MINI. Similar to the MK3 family, the Stealth mode will make your printer even quieter. This can be useful for example for overnight prints. You can switch between Normal and Stealth mode even during the print. Keep in mind that the mode will be activated once several G-code commands in the buffer (printer memory) are processed.

Once the Stealth mode is enabled, the firmware sets a limit to acceleration, feedrate, and jerk. Setting a cap on these parameters will lower the noise. While this reduces noise, it also affects the overall printing time.

In addition to Stealth mode, we are also adding support for the M73 G-code. You can find more information in this article.

Time Zone settings updated (MK4, MK3.9, MK3.5 and MINI)

This release increases the timezone hour offset range up to +14 hours and also introduces a timezone minutes option to select a timezone offset in minutes (0 min, 30 min, and 45 min).

This addresses issues #3550, #1779 and #3141.

Bed Level Correction (MK3.5, MINI)

This feature, originally introduced on the Original Prusa MK3 as an addition to the Mesh Bed Leveling (MBL), allowed experienced users to further compensate for any imperfections on the heatbed. The bed level correction gathers user data on how to adjust Z height in four directions around the plate (front, left, back, right) and then changes mesh bed leveling values through linear interpolation.

In most cases, this manual correction is unnecessary as MBL will handle compensation automatically. To adjust settings visit Control -> Bed Level Correction.

Revised Control menu (MINI)

In order to unite the user experience across all printers with the Buddy firmware, this release brings a revised Control menu on the MINI, where all tests were moved into the Calibrations & Tests submenu together with First Layer Calibration.

MCU temperature (MINI)

The MCU temperature is now available in the Sensor info menu.

MMU3 unit firmware auto-update

This firmware sets a base for the upcoming feature allowing you to update the MMU3 unit firmware from the printer. Currently, you have to connect a Micro USB cable to the control board in the MMU3 and update the firmware manually using PrusaSlicer.

Starting firmware 6.0.0-RC2 the printers with xBuddy mainboards (MK4, MK3.9 and MK3.5) will be able to flash the MMU3 unit automatically. The multi-material firmware will be from now on always part of the printer's firmware. Once you flash any newer printer's firmware, the rest will happen automatically, like magic.

However, to enable MMU3 auto-update, you have to also update the bootloader in the MMU3 unit's control board. This is a significant change to the entire MMU ecosystem, therefore we are currently running extensive tests covering all possible scenarios to ensure a flawless experience.

The tests are expected to be finished soon. The new bootloader will be then flashed to all MMU3 leaving the factory and also uploaded to GitHub and Help.prusa3d.com for all existing MMU3 users.

Note: This feature is not supported on the MK3S+. If you want to enjoy the MMU3 auto update feature, consider upgrading your printer to the MK3.5, M3.9 or MK4. Upgrade packages are available at the Prusa e-shop.

MMU firmware compatibility (file are included below):

• FW3.0.3+896.hex - compatible with MK3.5, MK4, MK3.9

Bug fixes

• A bug #3890 in the firmware 5.2.2 causing a shorter loading sequence into the MK3.5 MMU3 setup is now fixed.
• The previous release was missing an option to “Preload All” five filaments into the MMU unit and allowed to preload only one filament at a time. This is now fixed.

Known issues

• After multiple consequent power panics (power outages), the MK3.5 might not return to the correct Z-axis coordinate. This is a rare scenario from our laboratory tests. A typical single or double power outage works correctly.

6.0.0-RC1 Firmware for Original Prusa MK4 & MK3.9

Summary

• MMU3 support for the MK4/MK3.9
• Using the MMU3
• Touch support MK4/MK3.9
• Stuck filament detection
• Cold Pull
• Stealth mode
• Time Zone settings updated
• Improvements by Prusa community

This firmware introduces support for the Original Prusa MK4/MK3.9 with MMU3, which has been thoroughly tested and confirmed as stable. We have also included several brand-new features, which can be used regardless of the MMU3 unit and are still under development. As these features are undergoing further refinement, this firmware is labeled as a release candidate.

MMU3 support for the MK4/MK3.9

Currently, the MMU3 unit can be paired with MK3S+ and MK3.5, while this release adds support for MK4/MK3.9. It is important to note that each printer requires its own hardware upgrades as well as firmware versions to function properly with the MMU3.

Since the MK4 and MK3.9 utilize Nextruder, certain parts of the firmware had to be specifically tailored for its sensors (loadcell, filament sensor, etc.). This also affected the behavior such as calibration, automated checks, and troubleshooting compared to the MK3.5 or MK3S+ MMU3 setup.

Throughout the rest of these release notes, the MK4 and MK3.9 will be treated as equivalent printers, and only MK4 will be mentioned.

Single material MK4 calibration

As usual, before you install the MMU3 on your printer, make sure the MK4 was successfully calibrated and at least one single material print was done. The Multi-Material Upgrade adds more complexity to the entire setup and in case of issues, this move significantly improves the troubleshooting experience.

Upgrade your MK4 Nextruder

To use your MK4 with the MMU3, you need to upgrade your Nextruder with new printed parts, which will require a partial disassembly of the print head. All the parts are included in the MK4 MMU3 packages and available on the Prusa e-shop.

Tip: If you are already running an MMU3 with MK3S+ and would like to upgrade to either MK3.5, MK3.9, or MK4, the parts will be available shortly on the e-shop as well.

Connect your MK4 with MMU3

Before you fire up the printer, you need to use the MMU3 xBuddy cable, which is either part of the MMU3 MK4 package or can be purchased separately on the Prusa e-shop.

Enable MMU3 & MK4 setup

The multi-material setup is by default disabled and has to be enabled in two places:

• First, head to Menu -> Settings -> Hardware -> Extruder and set the value to “MMU”. This informs the printer that the Extruder was rebuilt with the MMU parts and the position of the filament sensor was changed. You will be asked to calibrate the filament sensor again.
• Second, go back to Settings -> and set the row “MMU unit” to “Enabled” (switch icon)

Tip: If you want to run single material prints without the MMU unit, the autoload trigger won't work as the position of the filament sensor is changed. For this reason, the feature is hidden from the menu, however, it is still present in the firmware and you can trigger the autoload by pressing on the screws with springs on the Nextruder. While using the full MMU setup this is not needed at all and the filament will be loaded all the way to the nozzle.

Shortly after enabling the MMU setup, the unit performs a self-test and rehomes both selector and idler. On the main screen, menu Filament will change its icon from single to multiple spools. Please note, that it takes approximately 10 seconds for the MMU3 unit to fully start up, during this period the Filament menu is disabled.

Update your MMU3

You need to update your firmware inside the MMU3 unit. Use the MicroUSB cable included in the MMU3 package. Download the firmware 3.0.3 linked under these release notes and flash it using PrusaSlicer like any other firmware. Note that the unit must be powered ON.

Please note, that unit's firmware 3.0.3 must be paired with the printer's firmware 6.0.0-RC1. No other version combination for MK4 is possible.

Note: The MMU3 firmware 3.0.3 can't be used with MK3.5 and MK3S+.

Calibrate your FINDA and Nextruder

Similar to the MK3S+ you need to manually adjust the position of the FINDA sensor in the MMU3 unit. Second, you need to recalibrate the filament sensor to the new parts, this is automated and you will be required to only insert a piece of the filament, the printer will load it inside the Nextruder and perform the calibration automatically.

Update your PrusaSlicer profiles

Make sure you are running the PrusaSlicer 2.7.3 (or later) and check for the profile update. Once you install the latest package, check the “Configuration Assistant” for new MK4 MMU3 profiles.

Tip: The G-codes from MK3S+ and MK3.5 MMU3 can't be run on the MK4 MMU3 setup due to multiple changes to the G-code execution (ramming sequences, wiping, …). For now, it is recommended to reslice the file.

Using the MMU3

General information

MMU3 for the MK4 brings some improvements and new features (e.g. inherited tool mapping from the XL). However, we wanted to ensure that the current MK3S+ users, who upgraded recently to MK4 will be able to use the MMU3 as they are used to.

To learn more about the features (Preload to MMU, SpoolJoin, Tools mapping screen, etc.) we recommend reading the 3D printing Handbook, which is part of the MMU3 package.

Single-material prints

Starting single-material prints is easier than ever before - just select the right printer tool and assign it to your G-code. The printer will start the print, load the selected filament, cool down a bit, perform the mesh bed leveling (MBL), and then draw the purge line.

Please note, that the tools mapping screen is displayed only when the print is started with no filament in the nozzle. Otherwise, the print is started directly without showing the tool mapping screen.

New features in development

Below are listed features that are close to being considered stable, however, some final polishing is still required. Therefore, you have to enable them manually from the menu for now.

Touch support (MK4)

The touchscreen has been part of MK4 from the very beginning of the production (which is also true for MK3.5 and XL). However, during the development phase, prior to the official launch, we encountered numerous challengers, including a hardware issue caused by one of the chips on the xBuddy board. Resolving these issues required extensive collaboration with our suppliers, multiple rounds of testing, and numerous adjustments to the firmware. This is why the touch feature is being announced today.

As mentioned earlier, you must manually enable the touch feature from the menu. Navigate to Settings -> User interface -> Touch.

With the touch enabled you'll be able to control the majority of items on the screen. You can swipe your finger up and down to scroll through the menu. Swiping left or right (depending on your preference) takes you one step back in the menu hierarchy.

There are some exceptions where the knob must be used, such as when setting the target temperature manually or while moving with any of the axes.

Tip: Touch feature is supported and will soon be enabled also for the XL and MK3.5. Stay tuned!

Stuck filament detection

Starting from this release, the loadcell sensor in the Nextruder will not only be used for the mesh bed leveling, but also for detecting whether the filament is stuck and not moving (e.g. when the nozzle is clogged).

When certain conditions are met, the print will be paused, filament unloaded and the system will notify you that the filament was most likely stuck. Once you check the filament, reload it back to the Nextruder, and then you can resume the print job.

It is important to note that detecting stuck filament is possible only inside the Nextruder, as pressure builds up from the nozzle to the upper part of the Nextruder. However, if your filament is tangled on the spool, there will be no internal pressure, just outside tension, which the loadcell won't be able to recognize.

Cold Pull

The Cold Pull method is a popular method used for unclogging or cleaning your extruder. Starting from this release we are implementing a new feature that will guide you through the entire process using a step-by-step Wizard and provide assistance.

Support for other Prusa printers is planned in a future release as soon as their implementation of the cold pull method is ready.

Stealth mode

Similar to the MK3 family, we are introducing Stealth mode, which will make your printer even quieter. This can be useful for example for overnight prints. You can switch between Normal and Stealth mode even during the print. Keep in mind that the mode will be activated once several G-code commands in the buffer (printer memory) are processed.

Once the Stealth mode is enabled, the firmware sets a limit to acceleration, feedrate, and jerk. Setting a cap on these parameters will lower the noise. While this reduces noise, it also affects the overall printing time.

In addition to Stealth mode, we are also adding support for the M73 G-code. You can find more information in this article.

Time Zone settings updated

This release increases the timezone hour offset range up to +14 hours and also introduces a timezone minutes option to select a timezone offset in minutes (0 min, 30 min, and 45 min).

This addresses issues #3550, #1779 and #3141.

Improvements by the Prusa community

Thanks to the ac...

5.2.2 Firmware for Original Prusa MK3.5

Summary

• Bed Level Correction
• Support for Revo hotend
• Mesh bed leveling fix (7x7)

This is a stable firmware release recommended for all users of the Original Prusa MK3.5. It brings full support of Revo hotends, allows to perform bed level correction and addresses mesh bed leveling issues.

Bed Level Correction

This feature, originally introduced on the Original Prusa MK3 as an addition to the Mesh Bed Leveling (MBL), allowed experienced users to further compensate for any imperfections on the heatbed. The bed level correction gathers user data on how to adjust Z height in four directions around the plate (front, left, back, right) and then changes mesh bed leveling values through linear interpolation.

In most cases, this manual correction is unnecessary as MBL will handle compensation automatically. To adjust settings visit Control -> Bed Level Correction.

Support for Revo hotend

This release provides full support for the Revo hotends. By default, the printer expects a stock Prusa hotend during the initial self-test. If this procedure fails, then the user is asked to verify the hotend setup and adjust the settings.

If you decide to change your hotend on an already calibrated printer, you can adjust the settings in “Settings -> Hardware -> Hotend Type”. It is recommended to rerun the “heater test” to ensure your new hotend is performing correctly.

Mesh bed leveling fix (7x7)

The previous firmware release included a bug reported by the Prusa community on GitHub. While performing the MBL, the printer used only a 6x7 point grid and omitted the left side of the heatbed, which in some cases resulted in uneven first layer height.

We would like to thank everyone who contributed to fixing this issue #3772.

5.2.1 Firmware for Original Prusa MK3.5

Summary

• MMU3 support for the MK3.5
• Using the MMU3
• Bug fixes

This is a stable release of the firmware MK3.5 recommended to all users. Starting firmware 5.2.1, we are rolling out official support for the MMU3 for this printer model. You need to update your MMU3 unit and calibrate the entire setup, so please read the instructions below carefully.

MMU3 support for the MK3.5

The latest generation of our Multi-Material Upgrade (MMU3) is now officially compatible with the Original Prusa MK3.5. This is the first release of the MMU3 working together with the 32-bit Buddy hardware. Some features are similar to the 8-bit MK3S+, some were improved fully utilizing the larger LCD of the MK3.5. Here is a quick overview of the hardware and software prerequisites with the following calibration setup:

Single material MK3.5 calibration

As usual, before you install the MMU3 on your printer, make sure the MK3.5 was successfully calibrated and at least one single material print was done. The Multi-Material Upgrade adds more complexity to the entire setup and in case of issues, this move significantly improves the troubleshooting experience.

Upgrade your MK3.5

To use your MK3.5 with the MMU3, you need to upgrade the upper part of the extruder with new printed parts, which we familiarly call “the chimney”. All the parts are included in the MMU3 package and will soon be available on the Prusa e-shop.

Tip: MK3S+ MMU3 owners, who are upgrading to the MK3.5 can keep their extruder intact as both MK3S+ and MK3.5 are using the exact same extruder parts.

Connect your MK3.5 with MMU3

Before you fire up the printer, you need to use the MMU3 xBuddy cable, which is either part of the MMU3 MK3.5 package or can be purchased separately on the Prusa e-shop.

Tip: MK3S+ MMU3 owners, who are upgrading to the MK3.5 need to purchase just this cable, the rest of the setup remains the same as on the MK3S+. For more information visit our MMU3 compatibility article.

Enable MMU3 & MK3.5 setup

The multi-material setup is by default disabled and has to be enabled in two places:

• First, head to Menu -> Settings -> Hardware -> Extruder and set the value to “MMU”. This informs the printer that the Extruder was rebuilt with the MMU parts and the position of the filament sensor was changed.
• Second, go back to Settings -> and set the row “MMU unit” to “Enabled” (switch icon)

Tip: If you want to run single material prints without the MMU unit, the autoload trigger won't work as the position of the filament sensor is changed. For this reason, the feature is hidden from the menu, however, it is still present in the firmware and you can trigger the autoload by pressing on the upper part of the idler door lightly. While using the full MMU setup this is not needed at all and the filament will be loaded all the way to the nozzle.

Shortly after enabling the MMU setup, the unit performs a self-test and rehomes both selector and idler. On the main screen, menu Filament will change its icon from single to multiple spools. Please note, that it takes approximately 10 seconds for the MMU3 unit to fully start up, during this period the Filament menu is disabled.

Update your MMU3

You need to update your firmware inside the MMU3 unit. Use the MicroUSB cable included in the MMU3 package. Download the firmware 3.0.2 linked under these release notes and flash it using PrusaSlicer like any other firmware.

Please note, that unit's firmware 3.0.2 must be paired with the printer's firmware 5.2.1. No other version combination is possible at the moment.

Calibrate your FINDA and “Chimney”

Similar to the MK3S+ you need to manually adjust the position of the FINDA sensor in the MMU3 unit and the Filament sensor in the “Chimney”. Please follow the official assembly instructions.

Update your PrusaSlicer profiles

We have prepared several multi-material test prints, which are available on Printables. However, if you want to print your own, make sure you are running the PrusaSlicer 2.7.1 and check for the profile update. Once you install the latest package, check the “Configuration Assistant” for new MK3.5 MMU3 profiles.

Using the MMU3

General information

MMU3 for the MK3.5 brings some improvements and new features (e.g. inherited tool mapping from the XL). However, we wanted to ensure that the current MK3S+ users, who upgraded recently to MK3.5 will be able to use the MMU3 as they are used to.

To learn more about the features (Preload to MMU, SpoolJoin, Tools mapping screen, etc.) we recommend reading the 3D printing Handbook, which is part of the MMU3 package.

Single-material prints

Starting single-material prints is easy as never before - just select the right printer tool and assign it to your G-code. The printer will start the print, load the selected filament, cool down a bit, perform the mesh bed leveling (MBL), and then draw the purge line.

Please note, that the tools mapping screen is displayed only when the print is started with no filament in the nozzle. Otherwise, the print is started directly without showing the tool mapping screen.

Bug fixes

MK3.5: Sensor info - board temperature missing

This issue was reported on GitHub as #3745 and later a pull request was suggested by Bjoern #PR3749. We would like to thank the community again for engaging in the development!