GCODE Z-offset

[amadois 0]

Hey guys,

 

I'm having some trouble with a fresh installation of Cura 3.1. When slicing my model Cura inserts a G0 (move) code and moves the nozzle 0.3mm upwards.

This causes the filament being painted too high, thus it has no contact with the heatbed.

 

When removing the 0.3mm offset everything works fine.

 

Does anybody know what's the problem here?

 

Thanks in advance

[gr5 2,189]

So Cura assumes that Z=0 has the head touching the glass and because your first layer is 0.3mm thick (that's the default bottom layer thickness even though the remaining layer heights are all 0.1mm).

 

So is there a way to level your head closer to your bed before starting the print?  If not you might be able to do:

G0 Z0

G92 Z0.3      ;tell marlin that we are now at position z=0.3 even though we know we are at position z=0.

[amadois 0]

Thanks for your reply.

 

Thanks for the hint. As it turns out Cura sets the initial layer height to 0.3mm which produces the error.

Setting the value to 0.1mm solves the problem.

 

Is it correct that selecting the 0.1mm profile sets the initial layer height to 0.3mm?

To me this looks like a bug. Who would want that?

[gr5 2,189]

It's definitely not a bug.  If you want the initial layer height to be 0.1 then it sets Z to 0.1 so the nozzle is 0.1 off the glass so there is room for a 0.1mm layer.

 

If you set the first layer height to 0.3 then it sets z to 0.3 so the nozzle is 0.3 off the glass so there is room for a 0.3mm layer.

 

So be aware that not only will you have the first layer starting closer to the bed, you will ALSO have 1/3 the extrusion because 0.1mm is 1/3 0.3mm and so you are getting 1/3 as much filament coming out of the nozzle.  So I'm not sure you are done with your adjustments.  I still think you need to level better such that Z=0 has the nozzle touching the bed.

[amadois 0]

Okay, I understand that point.

 

Actually I'm a bit confused about what you say about the leveling process. I learned that I should level the nozzle about the height of a receipt over the heatbed but what you say makes much more sense to me.

 

Thanks a lot for your help!