Z Axis Offset won't go negative

[ShipModeler 1]

I am trying to set the Z Axis offset within Cura and I am having an issue. I am using Cura 5.3. I tried installing the add-on for Z offset but it won't take a negative number. If I use a positive number (3.3mm) then it makes the distance between the nozzle and bed 6.6mm

 

So I thought I would just set it in the GCode startup. Again no luck. 

This is the code I used

 

; Ender 3 Max Custom Start G-code
G92 E0 ; Reset Extruder
G28 ; Home all axes
G29
G92 Z-3.3 ; Z offset setting
;G420 S Works for stored leveling settings
G1 Z2.0 F3000 ; Move Z Axis up little to

 

The line "G92 Z-3.3 ; Z offset setting"  seems to make the distance between the nozzle and the bed 6.6 whether the setting is Z3.3 or Z-3.3

 

Next how would I do a pause in GCode such that it would wait for me to acknowledge. I would like to have Cura pause the print right after the G29 (Level bed) command but I would need it to keep the bed and nozzle temp constant.

Thanks Ray

[Slashee_the_Cow 277]

I thought most people adjusted the Z axis offset in their printers, but I've come across plenty of situations where people need odd fixes for things, so I'm not here to judge.

If your nozzle is starting high enough to move it down 3.3mm, you could try the following:

G91 ; Relative positioning
G0 Z-3.3 ; Move Z axis down 3.3mm
G90 ; Absolute positioning
G92 Z0 ; Set current Z position to 0

Some Creality printers don't obey all commands, so I can't guarantee the following will work, but to make it pause and wait for you, it's just

M0

I prefer to let my printer tell me where it's up to but not wait for me, so I get it to beep and pause for a few seconds:

M300 P500 ; Play tone at default frequency for half a second
G4 S5 ; Waits for 5 seconds

 

 

A few more notes on your code:

53 minutes ago, ShipModeler said:

G28 ; Home all axes
G29

G28 disables bed levelling. G29 doesn't necessarily turn it back on (some printers will, some won't). I run an M420 S after my G28 to make sure bed levelling is enabled.

 

53 minutes ago, ShipModeler said:

;G420 S Works for stored leveling settings

M420 S enables bed levelling. To use specific levelling settings stored in the printer's EEPROM is M420 L<number>.

 

53 minutes ago, ShipModeler said:

G1 Z2.0 F3000 ; Move Z Axis up little to

Ideally, travel moves (without extrusion) are done using G0 to separate them from extrusion moves which use G1

Edited November 5, 2023 by Slashee_the_Cow

[ShipModeler 1]

Thanks Slashee, I will try those options.

 

Just as a note, I was using the printer to control the z offset but for whatever reason it quit retaining the settings even though I tell it to store settings. It did originally and then just quit storing them. I think it was about the time I installed the printer driver and connected a computer to the printer. I am no where good enough to tinker with the firmware so i thought if I could have Cura do the necessary steps ( preheat, level, z offset ) it would just be something I don't have to remember. If I can't get it all to work I can always go back to manually doing the steps.

 

Thanks Again.

[dbrandwood 0]

A lot of printers are set NOT to go below what it classes as zero, the issue effects those trying to setup BL touch's etc, a M211 S0 disables the limit (M211 S1 puts the limit back on) However, use extreme caution as it's easy to slam your nozzle into the bed if you get it wrong

[Slashee_the_Cow 277]

2 hours ago, dbrandwood said:

A lot of printers are set NOT to go below what it classes as zero, the issue effects those trying to setup BL touch's etc, a M211 S0 disables the limit (M211 S1 puts the limit back on) However, use extreme caution as it's easy to slam your nozzle into the bed if you get it wrong

If you're going to do that then please be aware that it will disable limits for every axis, so a bad command could have your print head constantly banging the edge of the gantry trying to move to a negative or out of bounds co-ordinate.

 

It's much better to just set a constant offset, depending on your needs.