Auto_Bed_Leveling: Enhanced G29 command

[Roxy]

Hey Roxy,
So in the end this Auto leveling is it more precise as mapping the bed ?

It is a little hard to answer your question the way it is worded. The upgrade just provides additional functionality, but is intended to be fully compatible with the existing code base.

By doing a G29 n 5 you will get increased accuracy because any error's in your Z-Probe measurements will average out. Also, you should have:

#define AUTO_BED_LEVELING_GRID

turned on because the 3 Point bed leveling (that is still in the code) is not very accurate as you move towards the unprobed corner of the bed.

As with the current marlin well, i still see sometimes that it doesnt print evenly,

Well... For sure you can get perfectly even prints. I suspect you are not fully dialed in yet. There are going to be two areas that might need attention.

First, do a G29 n 5 T and use that to iteratively (manually) level the bed. You need to have the enhanced G29 code to do this. If you don't have it loaded and running, you might want to jump ahead to the second thing. But it is much easier to be accurate with the second thing if you have this part right.

Look at the Bed Height Topology map that gets printed out. (You can do a G29 n 2 T for the first couple of passes until you get close to speed things up.) It really is helpful to get the first digit after the decimal place to be '0' for each corner. As in +0.0xxx or --0.0xxx You might not be able to get things that 'flat' and the bed leveling will compensate for that. But the closer you start to level, the better off you are. You can find video's of people raising a corner of the bed by 15mm and everything works just fine. Probably, they aren't showing the first video they took. Most likely it took them a couple of tries.

The other (second) thing you want to check is if you really have your Z-Probe-Offset correct. Once your bed is pretty level, take a look at the bead that gets laid down as the printer is putting down the first layer. You will be able to impact how 'even' the first layer goes down pretty easily by dialing in a 'correct' Z-Probe-Offset for your setup. (And what you measure it to be is just a starting point. The problem is, it is really hard to measure exactly where the micro-switch toggles. So just use your manual measurements as a starting point. Figure out which direction it needs to move and move it a little bit at a time until you get the bead looking how you want it.) The direction it needs to move is sort of inverted. If the nozzle is too close to the bed, you want to make your

#define Z_PROBE_OFFSET_FROM_EXTRUDER -x.xx closer to 0.0


After you get both of these items dialed in... I suspect you are going to be saying "This is great!!!!"

Thinking about installing this one atm..

Also can i still change the depth between glass and nozzle on my Marlin screen at Control or is that gone once i installed your lvling script?

I don't understand your question. Marlin doesn't have a screen? Unless you are talking about having an LCD panel in use with Marlin??? If that is what you mean... Yes, you should be able to swap out different plates of different thicknesses and everything should just auto adjust. This code just provides extra functionality to the released G29 code. It doesn't take away any features.