strange and incomprehensible mesh results

Dogma2k

I have a problem with the mesh. I have now made several meshes and whenever I define a large number (e.g. 144) of sample points, the deviation between the front and the back is approx. 0.18mm upwards.
However, if I only define e.g. 36 points, the deviation is only 0.08mm downwards.

Each mesh has the same conditions, 80 degrees bed temperature, 130 nozzle temperature, same speed, same area etc. only the number of points are different (in this example 6:6 to 12:12 mesh points)

How can that be?

PS My hardware Duet 6HC (2x X-Stepper, 2x Y-Stepper, 1xE-Stepper) and one Duet 3HC (3x Z-Stepper)

12:12 mesh

6:6 mesh

Dogma2k

I just found out something else.
I just made a G30 S-1 10x in a row (then the bed was always lowered 10mm).
Almost after each measurement, the distance measured by the sample increased. That would explain why it always ends up going so far into the +.
Why can that be?

Can it be because of this error?

dc42

@dogma2k this is a documented limitation, see https://duet3d.dozuki.com/Wiki/Duet_3_firmware_configuration_limitations#Section_Temporary_limitations. It is fixed in the latest 3.4beta build.

Dogma2k

@dc42
That's what I thought, thanks for the confirmation.
Which is the current beta7 (i.e. 7+4 or higher)
Or maybe the 3.4.0RC1 will come out soon? I'm actually not a friend of beta firmware

Phaedrux

3.4 RC1 should be soon if you wish to wait.