Z offset incorrect

Question

Repetier host 1.6.2. Used Slic3r and CuraEngine in RH1.6.2 to slice my prints.

OK, I have a problem. Z offset does not work. Well...

1. Flashed EEPROM clear.
2. Enabled EEPROM and CHIT CHAT within the firmware.
3. I've set -0.4 in Marlin firmware 1.0.2-1 stable and flashed it.

results in

    G28; home axis = works
    G29; auto level = works
    G28; it goes to home and then sets Z to 0.4
    G1 Z0; brings nozzle down from 0.4 to 0, so this works also.

But when I slice with Repetier host 1.6.2 with the latest slicer/curaengine, it does not go down 0.4 mm before starting to print. I've set the first layer to 0.2 mm, but when it starts printing the first layer, it goes from 0.4 mm (after home Z is on 0.4 mm) to 0.6 mm instead of 0.2 mm! ...

How do I fix this?

Gcode start:

    ;Generated with Cura_SteamEngine 15.01
    ; Default start code
    G28 ; Home extruder
    G29 ; Auto level
    G1 Z15 F100
    M107 ; Turn off fan
    G90 ; Absolute positioning
    M82 ; Extruder in absolute mode
    M190 S35
    ; Activate all used extruder
    M104 T0 S230
    G92 E0 ; Reset extruder position
    ; Wait for all used extruders to reach temperature
    M109 T0 S230
    ;Layer count: 226

It's definitely Repetier or its slicers. I'm using Cura 15.04.6 and it also calculates the offset set in Marlin when printing! I'm trying to use Cura 2.1 because it's newer, but I do not get the print USB option in Cura 2.1 :/

I just don't get it, it was printing very nice the first 4 layers, and suddenly it moved up more than 0.5 mm and continued printing there, in the air.

Yesterday's print:

Today's print:

Answer 1

Your question is a little hard to pin down, but I'll try to help anyway. :-)

Z-Offset:

• It appears you may be misunderstanding the way z-offset is supposed to work especially when it comes to Marlin setup and routine bed leveling and printing.
• This may help.
• And this

Print Quality and Skipped layer issues:

From your pictures, you do have some loose or wobbly belts, pulleys, rails, or other mechanical components causing excessive play in your x and y axis...very apparent with the way your layers don't align well resulting in the very visible lines. You can address this in two ways:

• Make sure your physical components are tight and rigid enough to handle the print speed you're using.
• Slow down your print speed to something that your machine can handle with reasonable quality...whatever reasonable is for you.

You mentioned skipped layers. I see that in your tower. This is most likely caused by:

• Tower legs too thin so Cura skips it because it can't fit there. I'd suggest using the layer preview in Cura, if the layer doesn't show in the preview, it won't print. If this is because the leg is too thin for your nozzle diameter, you could increase the scale of the tower, edit the model to have thicker legs, or install a finer nozzle.
• Issues with your mesh so Cura skips it. Also use Cura's x-ray view. If there are red areas, you have issues with your mesh. Search for ways to fix your mesh and make sure your model is good to print.

However, it could also be caused by issues with your filament feeding or your hot end. Clogs, snags, etc. If this were the case, your previews in Cura would all be fine. To solve this you could:

• Increase your print temperature slightly to ensure you're filament is melting quickly enough to support your print speed.
• Slow down to allow the filament plenty of time to melt.
• Make sure your feed system is snag-free.
• Make sure your feed system is clean and adequately gripping the filament so it can push the filament into your hot end reliably.

I hope this helps. :-)