Auto_Bed_Leveling: Enhanced G29 command

[Roxy]

Hi Roxy, would it be possible to do something like they do with the Repetier firmware?

Yes, that should be possible. The logic should map over. But I don't think very many people are using Repetier. Is that assumption not correct?

With normal PLA I have no problems but I can't get Lay-wood to stick on my mirror build plate so I'm using a acrylic plate on top of it which seems to stick much better.
However this plate has a few bumps and cracks but nothing worth compensating for. But after doing the G29 I get a very messy first layer because of the uneven spots.
I would like the auto calibration to only pick 3 points (delta printer) and only compensate for that, do you think this is possible with Marlin?

Well... I'm not sure if I followed everything, but it sounds like that acrylic plate is not very flat. Is that what you mean by 'uneven spots' ? As far as only doing 3 spots on a Delta printer, that should be just a matter of turning on the right options and setting where the 3 measurements will be taken on the bed. I would encourage you to do more than 3 spots, but if your bed is pretty flat and level, you may get good results with that.

[Egon van Engelen]

I'm sorry I made a big mistake in the first question, I meant of course to do this in Marlin because in Repetier it already works like that for delta printers, I was wondering if something similar would be possible with Marlin.

[Roxy]

The G29 Auto_Bed_Leveling is independent from whether you are running on a Delta or not. The G28 command makes an 'identity' correction matrix (1's running down the diagonal) that it multiplies against any future coordinate it gets. The G29 command just warms over that correction matrix so it reflects what is really going on with the bed. If you turn on both Delta support and Auto_Bed_Leveling, you should have what you want.

Unfortunately, I don't have a Delta printer so I can't verify that.

[Finetime2994]

The G29 Auto_Bed_Leveling is independent from whether you are running on a Delta or not. The G28 command makes an 'identity' correction matrix (1's running down the diagonal) that it multiplies against any future coordinate it gets. The G29 command just warms over that correction matrix so it reflects what is really going on with the bed. If you turn on both Delta support and Auto_Bed_Leveling, you should have what you want.

Unfortunately, I don't have a Delta printer so I can't verify that.

I just built a GMax printer and the auto bed leveling is not compensating for the bed enough as it isn't the most level bed ever... I am using an MKS Base V1.4 with a BLTouch sensor and Marlin RC5 firmware. The whole process works and I can see the z-axis adjusting but it is not adjusting a significant enough amount for the nozzle to stay a consistent distance from the bed. Right now I am using the grid and 4 probe points in marlin (so 16 points recorded). Is there a way I can get the auto bed leveling to more closely follow the curvature of the bed? I am eventually going to upgrade to glass (have acrylic now) to get a more level surface but I should have to given that I have ABL and a fairly accurate sensor. Will just typing G29 V 4 into my start g-code make it work or will I need to do more?

[Roxy]

Will just typing G29 V 4 into my start g-code make it work or will I need to do more?

The default is a 3x3 grid if you don't specify the number of points. So you would want G29 u4 T V4 or G29 P4 T V4 depending on where you got your code from.

You might want to try the RCBugFix file at www.github.com/MarlinFirmware/Marlin and turn on Mesh Bed Leveling. That might help you with the not flat bed.

[inventabuild]

Hi Roxy,

I finally got my auto bed leveling working. Here's a video demonstrating it:

https://www.youtube.com/watch?v=AnHCrnXoj9k

and here's the more lengthy post that includes a little more detail about the setup:

https://forum.lulzbot.com/viewtopic.php?f=16&t=4309

When will auto bed leveling with matrix be ready? I'll have to do some mods to my setup when that comes out.

Thank you very much for your help!!!

Mitch

[Roxy]

When will auto bed leveling with matrix be ready? I'll have to do some mods to my setup when that comes out.

Thank you very much for your help!!!

It is difficult to predict. The problem is free time that can be allocated to it. But I'm hoping it will be available for download in a couple of months.