Summary
- Gearbox gears calibration
- Improved fan self-test
- Improved hotend self-test
- Z-axis homing coordinates adjusted
- Known bugs
This firmware release 4.6.4 primarily focuses on adding features to make assembly of the MK4 kit easier. It extends the self-test by implementing new routines useful for detecting and avoiding issues with the MK4 kit. However, these routines are useful for regular printer service as well.
Firmware 4.6.4 is a direct successor of firmware 4.6.2. The firmware 4.6.3 is almost identical to 4.6.4, therefore it doesn't have its own release notes and won't be available for download.
Gearbox gears calibration
A new or serviced gearbox requires a procedure to “settle in” the gearbox housing. Starting this release there is a new step-by-step guide built-in to the firmware, which will help the user to follow the steps and successfully complete the calibration process.
For factory-assembled printers, this procedure is already performed in-house. It is required only for the newly assembled kits or after servicing the gearbox. The gearbox calibration is part of the Wizard. To start it manually go to the LCD menu -> Control -> Gears calibration.
Improved fan self-test
The fan testing procedure has been improved for this release. Previously, only RPMs (Revolutions Per Minute) were checked, but it was possible to plug the fans incorrectly (switch their connectors). The algorithm has been improved to verify whether the fan connected to a specific connector is performing as expected.
The test can result in:
- Success - Fan RPMs fall within the correct ranges
- One or both fans are outside expected RPM ranges: In this case, the test could not be conducted, indicating a possible hardware issue. Manual inspection is required.
- Fans are switched: The print fan RPM fall within the Hotend fan RPM range and vice versa. This suggests that fan connectors on the board need to be switched by the user.
Improved hotend self-test
The Nextruder heater block can be equipped with a Prusa silicone sock. This, however, changes thermal behavior during the heat-up procedure and as a result, the self-test can fail as it expects different values.
This firmware release allows the user to change the hardware setup and inform the system that the sock is now installed. This can be done either in Settings -> Hardware by toggling the option ON/OFF using a slider or immediately after a failed self-test with an option to repeat this test.
Z-axis homing coordinates adjusted
Until now the homing of the Z-axis was done inside the printing area based on the current size of a printed object. Starting this release the homing position is shifted outside the printing area.
Known bugs
- Boot loops can occur in some cases. In such a case a quick fix is turning the printer OFF and ON again. Developers are currently working on a fix.
- Red screen with I2C error - occurs rarely while the printer is booting up. Restarting the printer solves it. (use the main switch, not the reset button).
- If the print is paused for a long period, the nozzle cools down close to room temperature. Once the print is resumed the system incorrectly pauses the print again and it must be resumed by the user once more.