Mini 2.0 Z-axis Does Not Move for First Few Layers

General LulzBot Mini
#1

So I came across a strange issue with my mini 2. During a print my z-axis will not move for the first few layers. It is causing some serious over-extrusion at the bottom of my parts. The strange part about my issue is that the printer seems to know that the z-axis has not moved. For example, the first layer of a typical print on my printer may be at a Z of 1.81 as shown by the display. When the printer starts layer 2, the displayed Z value will remain the same at 1.81 and I can confirm visually that the z-axis has not moved. This will continue for a number of layers until finally the z-axis starts moving between layers. If I check my g-code I can confirm that the g-code does request the z-axis to move. It is almost like my printer is failing to read parts of the g-code. This happens with the latest firmware on the latest version of cura lulzbot.

Does anybody have any insight into what might be causing this issue or a possible solution?

#2

A couple additional things that I have noticed since my original post.

  1. The gcode I have starts at a Z value of 0.375. Could it be that the z axis is not moving because it is already starting above this value?
  2. When I was trying to move the x axis around it would occasionally fail to move the commanded amount. I would try to move it -10 mm and it would simply remain stationary. I am unsure if this would be a hardware or firmware issue. (Edit: I should clarify that this was after I moved it +80 mm, so it had plenty of room to move in the other direction.)
#3

What tool head are you using? Have you selected the correct tool head in your firmware? What is the version number for the firmware you are using? Can you post the gcode that experienced the issue?

#4

Hi, I am using the SE tool head, Cura Lulzbot Edition version 3.6.25, and firmware version 2.0.6.7 (I am almost certain of this since I updated my firmware a couple weeks ago). I was also using the following gcode:

LM2SE050MM_TestCylinder.gcode (1.1 MB)

I am away from my printer right now so I will have to double check the firmware later today.

Thank you

Edit: Also, please note that the slicer settings that I used are for ABS. However, I have been seeing this issue for about a week now with all prints I have attempted. I reset my slicer settings and tried printing with the preset for IC3D ABS and I still saw this issue.

#5

Have you tried reverting back to the older firmware and seeing if the problem persists?

#6

No, I am not exactly sure how to do that. Where can I find the older firmware files?

Edit: I also think I will try re-flashing the same firmware first, before I try reverting back to old firmware. I was seeing bed leveling issues with the original firmware.

#7

C:\Program Files (x86)\cura-lulzbot 3.6\resources\firmware
This is the default installation path, if you have installed it in another location then you will need to navigate there then follow the folder names.

For the Mini 2 SE you are looking for Marlin_Mini2_SingleExtruderAeroV2_1.1.9.34_5f9c029d1.hex

then using the upload custom firmware option you can navigate and select that file.

#8

Rolling back my firmware seemed to fix the issue for me. I am not sure if my firmware was corrupted or if it was an issue with the new version that caused my issue.