Will this probe work for the auto-levelling?

[insta]

Glad you did the research for me. Looks like I'll be updating some firmware too.

[willnewton]

Glad you did the research for me. Looks like I'll be updating some firmware too.

OK, but is your current firmware 1.1.0rc2 or rc3? If you have rc2 and need to upgrade to rc3 great. Disregard everything else I am about to post, as it is for reference for other folks.

If you are running 1.0.2, 1.1.0rc1 or earlier, then you don't have mesh bed leveling installed.

But Dag-nabbit! You are seeing is the Z jump around as it prints! Of course that is what you are supposed to see when you are printing in AUTO_BED_LEVEL! Willnewton is a dummy.

But have you ACTUALLY printed something that proves what you are seeing? Or are you just seeing it Z- translate and assuming it is compensating all over and making dynamic fits when it is really only fitting a plane? Like most folks, your bed is probably decently flat. The problem is you can't verify the z moves visually because it just jumping all over from point to point as it zigs and zags all over in every direction making prints and your eyes can't resolve what it is seeing like a micrometer. You especially can't tell if you are running any Z-lift.

A simple print will expose what kind of leveling you have. CAD up a 1x1mm profile rectangular outline the max size of your bed and print it. You only have to watch the first perimeter print. Your print speed will be slowed because you probably have 1st layer reduction turned on, this will help your observation. This rectangular print will force your printer to make long, slow transits along a single, straight 0º and 90º axis only.

If you have auto bed leveling, your Z will compensate in one direction only as it makes a long transit. If you have mesh bed leveling it will only move in one direction if you have too few points selected or your bed is damn flat and your machine is tight. Congratulations, you don't need mesh leveling!

If you have Mesh bed leveling, your Z will compensate in both directions as it makes these long transits, possibly making multiple changes.

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Here is a tutorial I worked up for ya'll
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OK, I have officially gotten MESH_BED_LEVELING running. There are several things to take care of while you are doing it. First, just set up Auto_bed_leveling and your probe and probe offsets, etc. Get it so you can make a decent print. If you solve all the problems of getting the probe and leveling working in Marlin 1.1.0rc3, then you are definitely ready for mesh leveling. Sorry, this is not about how to set up your probe, install firmware, and all that.

You also need an LCD with an input knob to set this up. This is not automated probing, you must do it manually, but it is not hard. They are working on automatic mesh leveling, so hopefully it will get easier in future releases.

-Make sure your #define EEPROM_SETTINGS and #define EEPROM_CHITCHAT are enabled (delete the //) in the firmware so you save the measurements you will be taking.
-Also activate #define MANUAL_BED_LEVELING and #define MESH_BED_LEVELING. As long as your bed dimensions are correct in Marlin, you don't need to make changes to the settings there, except to choose how many points to probe.
-Upload the firmware to the board.
-Restart the board.

-Open your control software and connect to the printer.
-HOME everything and just make sure it is working as expected.
-Heat your bed and nozzle so it is all up to temp.

-On the LCD control, open the Prepare/Level Bed folder.
-Slide a feeler gauge or piece of paper under the nozzle. I used a thin piece of paper folded over. Make sure no filament is oozing out making a mess.
-Turn the LCD knob to raise and lower the Z. I get it to just trap the paper still and then one click back to set the paper so it will just slide around.
-Push the knob to accept and it will go to the next point, stepping through the grid you have defined in the firmware, giving you a chance to adjust each point with the knob.
-I recommend just setting you points to a 3x3 grid for your first run through and increasing the grid points as needed once you have confirmed it all works. I am using 5x5 points on an 18x24" bed

-On completion, go to your computer printer communication window and send G29 S0 or just G29. It should spit back an array of numbers at you. If it doesn't or says "Mesh leveling not installed", it didn't work.
-Now type M500 and send to save this grid to the EEPROM. Don't forget this or you will have to redo the manual leveling on restart.

-In your starting gcode scripts, you probably have your print start with a G28 (HOME all) followed by G29 if you have activated Auto Bed Leveling. You should remove the G29 code. It is not needed now that the Mesh Bed Leveling values are stored.

That's it! Now print that rectangle again and watch the magic. You may have to adjust your starting Z-offset to fine tune the first layer height. You will have to go through the leveling process again if something gets out of whack. As mentioned, the hope is that Mesh Bed Leveling and Auto Bed Leveling are merged in a future release so this is an automated process. Currently, this is still beta-level stuff and subject to change.

You can also manually adjust your grid points after the mesh level calibration. More info on all of this stuff is here. https://github.com/MarlinFirmware/Marli ... d-leveling

[willnewton]

Here is what you want to see G29 give you with a 5x5 mesh leveling grid.

Yes, this Mic6 bed is super flat. The frame however is made from EMT, with printed parts rolling on skateboard bearings, on a plywood base. It is rigid in general, but not precise the way a linear rail is, but the imperfections are repeatable!

The top left number is the X0 Y0 Z-offset (front left bed corner). The bottom right number is the X600 Y440 (back right bed corner) .

That back left corner is crazy off. There is .8mm difference from highest to lowest point.

MESH_BED_LEVEL don't care!

meshlevelshot.jpg (53.19 KiB) Viewed 9697 times

[Jules]

You guys are so scaring me off of auto-leveling!

[willnewton]

Hey Jules, I wrote that tutorial because it seemed like a piece of cake compared to your manual and dual extrusion!

I don't think leveling is scary anymore. I have screwed it up every way possible. I even broke my extruder mount smashing it into the bed. Get your probe triggering first (a battle unto itself) and only make a few changes at a time once you have the base settings done.

Thanks to insta's question, it lead to solving a MAJOR issue with my own large printer.

As for the M2, I just found that the longer I have had it, the better I learn to place prints at the correct first layer height, remove prints carefully, and keep the bed level in general. I might re-adjust my bed a couple of times a year. I don't think it needs this feature yet.

But imagine a day in the not-so-distant future when MGIII's ship from the MG factory with all the probe hardware installed and firmware with a fully realized automated mesh leveling feature!

[Jules]

Can't help it....it looks like so much Greek to me! (Think i'll stick with eyeing it at nozzle level...it's worked so far.)

I'm not having to sell prints though, so it might save time if I had a bunch of prints that needed to be perfect, and on time.

[ryaneb85]

Is there an easy way to check what version of Marlin is running on the M2? I may have forgotten what I put on it...

Also, can you not do this via the command line of S3d/Octoprint, or is an LCD display absolutely required?

[willnewton]

Sure, just watch the Comm window when you connect to the machine with Simpify3d. The firmware is one of the first stats to come up. You will probably need to deselect the "Verbose" box to stop the scrolling.

Yes, you can do this via the Comm window and gcodes and tuning the Z-height via Jog Control window. It's just not as easy to set the Z-heights as the knob on the LCD.

Check the link in my previous post with the tutorial for details on G29, G29 S0, G29 S1, and G29 S2 codes that are used for manual setup of the mesh.

[PcS]

With a mic 6 plate and the m2s new spider for leveling this is really not needed. Lol but thanks for the info and write up.

[insta]

With a mic 6 plate and the m2s new spider for leveling this is really not needed. Lol but thanks for the info and write up.

I'm doing this with thin (well, not as thin as I thought) sheets of steel and BuildTak, making DIY Zebra plates. The MIC6/spider has its place (on my dual) but these are the general purpose machines.