Need calibration option for nozzle height from buildplate when active leveling is enabled

[bjorn 9]

Hi,

When I use active leveling, my first layer is printed to close to the bed. This results in a very wide layer (~ 150%) which gives a sharp edge on the bottom of my prints which I need to remove manually if tolerances are important .

I can imagine the active leveling process is perfectly capable of measuring the difference between multiple locations as a relative value, but it seems to me the absolute height might need some calibration options.

Ultimaker support told me there is no such possibility, other than switching to manual leveling, but imho that's not a solution to the problem. I'd like to use active leveling, since it's a great feature.

I would love to have this procedure or something similar:

First enable auto leveling

Not happy with first layer height? Go to Settings - > system -> calibrate -> Active leveling Z calibration

This would start a test print where some figures are printed with minor adjustments in the Z value. After this print, the user can select an offset from the automatic measured Z, for example +0.07mm.

Obviously, at the moment I would be more than happy with only the option to set the value without doing a test print.

This would greatly improve my prints.

Thanks for considering,

Regards,

Björn

[kristoffer 2]

I deactivated active leveling. Everything is fine now. I don't really see a need for it anyway.

There are 3 screws to adjust. Set it and forget it!

[bjorn 9]

Of course that's an option, but nevertheless, if the active leveling would be improved like suggested, I would still prefer it. It was one of the reasons to upgrade from UM2+ to UM3 actually.

[neotko 1,417]

If you make a program to access the store Z values inside the firmware (text files) you could do that, but far from onthefly.

I have forget about auto calibration. I edit the firmware to set paper at 0.00 and then I do calibration manually using the firmware sensgcode, that for me is the only way to get a really accurate and consistent calibration.

Also, calibration does shift the print on 1/16 steps resolution, so for accuracy on the first 20 layers or so, I prefer to be in control of what will happen to the printer.

Personally I don't see any use for the current way autopevel works, I would prefer a system that allows the user to do actually be able to level the bed. But ofc, that's just firmware, so is possible.

To bes bunt, I see clear visible first layer problems when the firmware tries to think for the user. For example internally the first layer is supposed to be 0.15, but the calibration paper is 0.1 (and hardly that paper is 0.1 exactly) so the firmware wants to force a 0.05 swuish on the bed for adhesion. That's stuff nice for new users, so they don't flood the forum with 'why it doesn't stick'. The downside is that the users that have been users printers al this years, already know how to do that.

Basically UM3 features try to make it more user friendly at the expense of real accuracy and precision that can only be achieved by gauge fellers, manual calibration and hours and hours of prints.

[tomnagel 126]

I've seen more requests for a feature to tweak the first layer. It is probably a very simple addition to Cura.

In the mean time, would it be possible to make a very simple Cura plugin that inserts a single command somewhere in the beginning of the gcode, instructing the printer to do a relative movement of for example 0.05mm upwards?

I've never made plugins, but it's probably not difficult.

Please note that Active leveling is also used to measure the z-offset between the nozzles. It does so very accurately, probably better than manual!