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MarlinFirmware / Marlin

Marlin is an optimized firmware for RepRap 3D printers based on the Arduino platform. Many commercial 3D printers come with Marlin installed. Check with your vendor if you need source code for your specific machine.
https://marlinfw.org
GNU General Public License v3.0
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Continue after Power-Loss, gantry drop, steppers not locking, print resumes at lower height #18332

Closed B-rad888 closed 4 years ago

B-rad888 commented 4 years ago

Bug Description

Continue after Power-Loss, gantry drop, steppers not locking, print resumes at lower height. I think this has to do with the software. When I raise the z height from the screen and immediately power off, I do not get any drop in the gantry. However, when resume print function is activated it raises the gantry and when power is fully drained it drops slightly maybe 1mm - 2mm. It is enough of a drop to not be successful when resuming. I believe there is no function locking the steppers after the raise. I do not know this because I don't know the code that operates this function but it makes sense. I have tried many different heights (for the raise function #define POWER_LOSS_ZRAISE ) from 10mm all the way down to 2mm. I still get a drop in the gantry. I was thinking that there may not be enough power to raise the gantry and then lock the motors, but after my tests there is really nothing else that I can think of doing besides adding a dual Z setup or anti backlash nuts to stiffen up the Z axis and prevent drooping. However I believe this could be achieved with software since in my other tests this only happens with power loss recovery. Not with manually raising the Z axis from the screen and powering off .

My Configurations

Ender 3 pro SKR 1.4 Turbo BTT TFT35-E3 V3.0 Display Touch Screen BTT SFS V1.0 Smart Filament Sensor BTT UPS 24V V1.0 Resume Printing While Power Off Module

Config H and ADV 1.zip

Marlin bugfix-2.0.x (latest release)

Steps to Reproduce

Turn power off while printing watch gantry raise watch gantry slightly drop when power is fully drained

Expected behavior: gantry to raise and lock with no drooping

Actual behavior: gantry slightly drop when power is fully drained

InsanityAutomation commented 4 years ago

This is a mechanical issue. The firmware has absolutely no way of knowing about or correcting for this. Increase tension of the rollers to help prevent it, or mod the machine with a Z-Max switch so that it can rehome to the top and configure the offsets correctly.

github-actions[bot] commented 4 years ago

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.