How do I enable MESH leveling for the print?

PaulHew

In my experience I manually level the bed using to 4 screws on my ender3.
I try and make it as level as possible using paper gauge between nozzle and bed.
Not teaching sucking eggs, I release the x/y steppers so I can move the gantry. Z is jogged down to grip paper, but stepper is engaged.

The I run the mesh after heating the nozzle to 160 and bed to 60
I also have 2 mirrors I use. I rename each heightmap to mirror 1 or 2 and call each mirror from cura’s start code.

devleon

@Rat_Patrol

I too had my offset from CAD, but turns out, it's not correct, since tolerances make things imperfect. Put a paper on the Heatbed, and slowly and manually run the nozzle into it, leaving a tiny mark, and also mark where your bed Probe is. Now measure everything and use that.

I had the same issue of thinking that mesh bed leveling was doing a bad job, until I remeasured my offset and realized I was off my 10mm.

Phaedrux

@Rat_Patrol said in How do I enable MESH leveling for the print?:

M558 P9 H5 F300 T6000 ; set Z probe type to bltouch and the dive height + speeds
G31 P500 X-32.201 Y-26.389 Z3.00

You can increase the accuracy and repeatability of the BLTouch by tweaking those settings a bit.

M558 P5 H5 F100 T6000 R0.5 A5
G31 P25

Then use this link to calibrate the trigger height and measure the X Y offset for the rest of G31.

https://duet3d.dozuki.com/Wiki/Test_and_calibrate_the_Z_probe#Section_Calibrate_the_Z_probe_trigger_height

droftarts

@Phaedrux said in How do I enable MESH leveling for the print?:

M558 P5 H5 F100 T6000 R0.5 A5
G31 P25

Don’t you mean M558 P9 H5 F100 T6000 R0.5 A5 ?

Ian

Phaedrux

@droftarts absolutely I did!

Rat_Patrol

Its not that the initial layer height is just wrong everywhere, some parts of the print have major squish and others are just fine.

Rat_Patrol

I did run through the BLTouch probe calibration procedure (ended up at 2.95mm IIRC). I designed my extruder carriage, so I just took the probe offset from the nozzle from Fusion, so it should be darned accurate.

Phaedrux

@Rat_Patrol said in How do I enable MESH leveling for the print?:

so it should be darned accurate.

There was a post just yesterday of someone using the measurement from CAD and then measuring it physically and it was off enough to matter. So at least verify that it's accurate. A bad offset would give results similar to what you see.

The slower feed rate of the probe move helps to improve the consistency of the BLTouch and it's forced to have at least 2 probes match which helps reject off values. Again, a variation in probe trigger height could describe what you're seeing.

Rat_Patrol

Did I input my probe offset correctly in config.g?

Compared to X0 Y0, my probe is negative in both axis, so there is actually no way to measure the extreme right side of my bed with the probe.

I have the flu, but if I'm thinking properly, the probe offset should be negative, right?

Phaedrux

@Rat_Patrol said in How do I enable MESH leveling for the print?:

the probe offset should be negative, right?

X would be negative based on your description, but I'm not sure about your Y. Negative Y would put the probe in front of the nozzle.

Rat_Patrol

Yes, the probe is in front of the nozzle.

TaDDragonZ

Looks like the same error I have, I will check the probe offset right now.