First Layer Calibration (MINI/MINI+)

Too high

You want the line flattened, but not squished. On the square at the end of the test line, you do not want any gaps between the lines (left picture), which means it is too high. In that case, the value will be too close to zero. Prints will not adhere and can come loose during printing, which can, in turn, cause a blob.

Too low

If the nozzle is set too low (right picture) you will see the line squished completely flat and the end square will have ridges between the lines. This is a clear sign of the nozzle being too close. The value will then be too far away from zero. When it is too low, the edges of the square can also start curling upwards. In the extreme, the filament will be spread so thin you will be able to see through the printed filament. This will clog your hotend.

Just right

A correct adjustment will show you an even surface (center picture), with no gaps, nor ridges, between the lines. As stated, the numeric value depends on the exact position of the SuperPINDA/M.I.N.D.A. sensor, which will be unique to each machine and means nothing without a visual reference. However, a common range is from -0.400 to -1.900.

Nozzle adjusted too high	Nozzle adjusted perfectly	Nozzle adjusted too close

Textured sheet

The textured sheets are thinner than the sheets with smooth PEI, therefore you need to move the nozzle bit closer, but you are seeking the same results as with the smooth sheet. Again, if it is set too low (right picture) the filament can start curling up around the edges like it is not adhering. The numeric value will be too far from zero and must be adjusted back.

If set too high, you will see the line being round, and have gaps between the lines of the end-square. In this case, the value is too close to zero.

When to run the first layer calibration

Generally, the first layer calibration should be performed every time there is a major change in the assembly. This includes changing the nozzle, extruder upgrades, or other updates to any axis. You should also run all calibrations if you move the printer to a different location.

For First Layer Calibrations with other nozzle diameters than 0.4 mm, please see this article.

Steel sheet profiles

Since the thickness of the different flexible steel sheets varies with the type, you will require a separate Live Z adjustment for each sheet. Therefore the printer offers 'Steel sheet profiles', where you can set a first layer calibration for each sheet you may have. More info in Steel sheet profiles.