Anycubic mega s with newest octoprint extruding incorrectly

What is the problem?

After flashing Marlin firmware onto my Anycubic Mega S, I am unable to get a quality print out using the Octoprint server I set up. When I extrude filament via the interface it appears to extrude a nice solid string. When I set a print to run, the print seems to struggle making a solid string which makes it look lumpy or not even adhere to the bed.

What did you already try to solve it?

I have tried setting the print heat to 180 instead of 200. I have printed with my slicers default settings. I have tried to slow down the print speed. I have adjusted the bed level. I have set an offset on the z axis to account for a possible too close to bed issue.


Additional information about your setup

Octoprint 1.4.0
Octopi 0.17.0
Raspberry pi 3
Marlin for Ai3MS 1.4.6 (1.1.9)

I’m also attaching an image of the results:

There is no octoprint firmware for 3D printers - I guess you're mixing something up :slight_smile:
It's a software that lets you control your printer via serial connection (USB for example).
The firmware on your printer is probably Marlin.

Does your printer support auto leveling? BL-touch or something else?

Ahhh yes, sorry, I was writing this on my phone and clearly got lost in the thought.

My Anycubic was flashed with Marlin, newest version available from here:

The version is 1.1.9 of Marlin, and 1.4.6 of this custom version for Anycubic i3.

And to answer your question, no I do not have any auto-leveling upgrades installed. I've tried a couple things with leveling the bed, and I've tried to get it as close as possible and then to do a z-axis offset that brings it up just slightly to match the layer thickness that I've set. It didn't help at all with this. I must be missing something clearly.

Alrighty :slight_smile:
I found this in your serial.log

Send: N10 G21*43
Recv: echo:Unknown command: "G21"

It's one of the first things after the targed temperature was reached.
G21 changes the units from inches to millimeters.
So that could be the reason why your printer doesn't do what you tell it to do.

I hope this custom marlin isn't based on the anycubic marlin.
They have done some really weird stuff with their marlin fork.

But let's wait - maybe somebody got another idea.

Edit: also check this out

Enter M115 in the terminal tab and check if the output is simalar to the one in the linked post.