1

Hi all,

I’m using an ANET A8 currently without probe sensors. Having recently upgraded to Marlin 1.1.8, I decided to try the Mesh Bed Leveling feature (enabled in config file before flashing) since my aluminium heatbed is slightly warped in the middle (bowed ever so slightly upwards).

After performing the G29 probe via the LCD screen for the 9 spots on the bed, I saved the mesh to EEPROM and added M420 S1 after every G28 I have in my start gcode and ran the print. However, what I noticed is that while my priming / cleaning line of extrusion works fine, the print head goes and start printing at the wrong place entirely when the actual print job starts.

My start gcode: G21 ;metric valuesG90 ;absolute positioningM82 ;set extruder to absolute mod - Pastebin.com

Basically, everything above works fine, but when it starts printing it goes way off as seen in the image here.

May I know how I could go about troubleshooting this error? Thank you.

2

Did you ever solve this? I am seeing the same problem. When activating the mesh the X/Y is off center.

If I manually edit the gcode and comment out the “M420 S1” command, it prints fine.

So when the mesh is activated the print X/Y seem offset.

3

I have the same problem! I have reviewed the marlin several times and I can not solve it! in version 1.1.6 I do not have this problem!

4

Unfortunately nope. I have since changed to a glass bed and although non-causal, I haven’t needed to manually level the bed in close to a month (of daily prints). On hindsight I may attribute the frequent need to level my bed due to the pulling / yanking of my prints off my taped heat bed which would have led to gradual shifts in the bed screws over time since I print fairly often. Glass bed prints pop off themselves cleanly and as such I seldom need to touch the heated bed at all.

Currently, the only time I may need to re-level the bed is when I change the nozzle or when I notice a distinct non-uniform first layer once in a blue moon.

5

Have you tried reverting to the previous version then? If that worked fine and there are no essential updates in the latest firmware it may be worth to save yourself the effort - unless of course this could be fixed somehow.

6

As I could not resolve it in version 1.1.9 or 1.1.8, I went back to using version 1.1.6 and I do not have this problem.

7

I was able to figure out the cause of my manual mesh leveling being messed up on the Anet A8 with 1.1.9, and how to avoid it. I am now using 1.1.9 and using manual mesh leveling.

For me it was my startup g-code in my slicer. I haven’t isolated it to the specific line, but I believe it was a move outside of 0,0 (it was a negative number on x to do a purge outside the bed before going to do the actual print).

If I changed the startup g-code to mimic what I do on my CR-10 which is just a purge line up the left side of the Y, the print works fine.

Here is the problem startup g-code that when used causes my print to shift and be way messed up.

G28 ; home all axes
M420 S1
G1 X-10 Y20 Z0.2 F3000 ; get ready to prime
G92 E0 ; reset extrusion distance
G1 F200 E10 ;extrude 3mm of feed stock
G92 E0 ;zero the extruded length again
G4 P5000 ; pause 5 seconds
G1 F9000

Here is the g-code that I use on my CR-10 which uses 1.1.9 and has been doing mesh bed leveling fine.

G28 ; home all axes
M420 S1
G1 Z5 F3000 ; lift
G1 X5 Y10 F1500 ; move to prime
G1 Z0.2 F3000 ; get ready to prime
G92 E0 ; reset extrusion distance
G1 Y80 E10 F600 ; prime nozzle
G1 Y100 F5000 ; quick wipe

I tried removing the pause in the first startup, and the first reset of extrusion, but that didn’t help. I really think it is the G1 X-10 line. I haven’t verified it, because when I switched my Anet A8 startup to the CR-10 startup, it just worked.

1 Like
8

Thank you for sharing! I
put this script and I had no more problems with marlin 1.1.9 !! I spent weeks looking for a solution, and thinking it was a misconfiguration in marlin.

9

Awesome, thanks for sharing. I’ll give this a try soon.