Why is there no Z-Offset setting in Cura at all?

[cnd 0]

GCode carries these commands..

 G28 Z0

 G92 Z0.2 

which let the user define the distance between the build plate and the nozzle (in my example above, it's 0.2mm)

 

That's a REALLY important number, because Cura will never output Z0 (if you set a layer height of 0.2mm, Cura's first layer will be Z0.2 - which, combined with the fact that my nozzle (and *Everyone else's*) does not touch the build platform at Z0, means that Cura is printing a 0.4mm high first layer, and wrongly thinking that it's 0.2mm high.

 

There are some ghastly kludges to try and overcome this mistake (like setting a first layer extra flow rate) - but this all seems really puzzling and bizarre to me.

 

The math to calculate exactly how much filament to extrude is going to get the answer 100% correct for EVERY layer (first included, no random kludges necessary) if Cura simply had some way for us to tell it what our Z Offset actually is.

 

Is there some sensible reason for this support being missing, or did the devs just never think about this properly in the first place?  It seems really bizarre to me - it's so incredibly obvious, and Cura is not the only slicer that skips right over this critical bit of information.  Maybe this is one of the contributing reasons for so many people having first-layer problems - software that has no way to properly compute a first-layer flow rate, because the programmers never gave anyone an input box to tell it what the Z offset is...

[cnd 0]

And before some smartypants says "edit the gcode" - keep in mind there's tens of millions of 3D printers in the world, and the overwhelming majority of them are run by "normal people" (not supercoders who know how to edit code)

[ahoeben 1,431]

There's a plugin for it in the Marketplace.

[Cuq 71]

@ahoeben : Don't feed the troll GitCnd is back : https://github.com/Ultimaker/Cura/issues/10893#event-5777330110

[GregValiant 548]

"edit the gcode"

[ahoeben 1,431]

I don't see this post as particularly trollish. Not everyone knows there's a plugin for this, so why not be helpful and say spread the word? (if only for others who find this post through some search).

 

https://marketplace.ultimaker.com/app/cura/plugins/fieldofview/ZOffsetPlugin

[cnd 0]

Interesting! - and 317,000+ downloads, from a guy who actually worked on Cura for Utilmaker... which begs the question: why was he forced to release this as a plugin, and what politics prevented this setting finding its way into the product?

 

I wonder if it's some kind of marketing decision, to deliberately give non-Utilmaker users more difficulty with their first layers...

[AndersK 58]

I have used Ultimakers for about 4 years and never had a need to adjust z offset

I have other machines where it is necessary (not done in the slicer though) but I do believe the auto calibration actually works for the Ultimakers.

 

For those who need to fiddle with it, the plugin is right there for it.