Mid Air Prints unless I Restart

Phaedrux

What do you have in homeall.g (G28)?
What do you have in bed.g (G32)?
What do you have in your slicer end gcode?

p40whk

; homeall.g
; called to home all axes
;
; generated by RepRapFirmware Configuration Tool v2 on Thu Jan 03 2019 13:44:38 GMT-0500 (Eastern Standard Time)
G91 ; relative positioning
G1 Z5 F6000 S2 ; lift Z relative to current position
G1 S1 X-240 Y-240 F1800 ; move quickly to X and Y axis endstops and stop there (first pass)
G1 X5 Y5 F6000 ; go back a few mm
G1 S1 X-240 Y-240 F360 ; move slowly to X and Y axis endstops once more (second pass)
G90 ; absolute positioning
G1 X15 Y15 F6000 ; go to first bed probe point and home Z
G30 ; home Z by probing the bed

; Uncomment the following lines to lift Z after probing
;G91 ; relative positioning
;G1 S2 Z5 F100 ; lift Z relative to current position
;G90 ; absolute positioning

; bed.g
; called to perform automatic bed compensation via G32
;
; generated by RepRapFirmware Configuration Tool v2 on Thu Jan 03 2019 13:44:38 GMT-0500 (Eastern Standard Time)
G28 ; home
G30 P0 X20 Y20 Z-99999 ; probe near a leadscrew
G30 P1 X115 Y115 Z-99999 ; probe near a leadscrew
G30 P2 X210 Y210 Z-99999 S2 ; probe near a leadscrew and calibrate 2 motors
G29 S0 ; probe the bed and enable compensation
G28 ; home

Slicer End-Code:

G91
G1 Z10 E-1 F1200 ; move Z up and retract filament 1mm
G28 X0 Y0 F1200 ; Home X and Y Axis
M104 S0 ; turn off extruder
M140 S0 ; turn off bed
M84 ; disable motors

Phaedrux

Does the printer not home itself when starting the new print?

What firmware version are you using? DWC version?

p40whk

It does home itself, and DWC is at 1.21.

Phaedrux

@p40whk is the firmware at 1.21 as well?

There was a bug around that version that would stack the z offset causing problems like you describe. I suggest you upgrade your firmwares.

p40whk

Thanks but I misspoke, I wasn't at the computer where my printer is but I am up to date on firmware

RandomFactoid

I've seen at least 3 posts of this kind (one from myself) about this exact issue - Z height increment between subsequent prints. Don't think there was ever a solution but to babystep for the 1st layer (in my case for instance the Z babystepping required would be around 0.4-0.5mm) and then reset babystepping for the 2nd layer and magically 2nd layer comes back to normal layerheight. Interestingly, even though it prints in air, stopping the print and sending G1 Z0 sends the nozzle to the bed as it should be. I ended up migrating to klipper for this very reason, but reverted back as DWC/PanelDue were too much of a sacrifice

Can't wait for a solution. Btw, if it'd help with debugging, i'm happy to post my configs.

dc42

When the G32 leadscrew bed levelling runs at the start of your print, does it run correctly at the start of the second print, and what corrections does it report?

dc42

@randomfactoid said in Mid Air Prints unless I Restart:

I've seen at least 3 posts of this kind (one from myself) about this exact issue - Z height increment between subsequent prints. Don't think there was ever a solution but to babystep for the 1st layer (in my case for instance the Z babystepping required would be around 0.4-0.5mm) and then reset babystepping for the 2nd layer and magically 2nd layer comes back to normal layerheight. Interestingly, even though it prints in air, stopping the print and sending G1 Z0 sends the nozzle to the bed as it should be. I ended up migrating to klipper for this very reason, but reverted back as DWC/PanelDue were too much of a sacrifice

Can't wait for a solution. Btw, if it'd help with debugging, i'm happy to post my configs.

Are you able to construct a short GCode file that demonstrates this if I run it twice? Preferably without involving heating or extrusion.

Are you also using G32 leadscrew bed levelling?

RandomFactoid

@dc42 will try to do that asap...maybe today.

I am using G32 gantry leveling on Voron 2.1 using 4 z steppers with corrections of 0.0x or 0.00x on each one after 3 passes.

p40whk

@dc42 said in Mid Air Prints unless I Restart:

When the G32 leadscrew bed levelling runs at the start of your print, does it run correctly at the start of the second print, and what corrections does it report?

Yes, it does run correctly at the start of the second print however, I didn't note what it reported, I'll set up a couple of jobs today and check that.

RandomFactoid

@dc42 thanks to your suggestion about the simple gcode, I think I found the problem.

Apparently if you have G10 in your pause.g (or, I suppose anywhere in your Gcode) and have Z hop defined in M207, after cancelling the print (or, I'd guess, finishing it without unretracting), after starting a new print, z=0 becomes the value of the Z hop height in M207, because it zhops, the print gets cancelled or finishes and never actually zhops down to previous height.

I tested this by uncommenting G10 from my pause.g and the problem disappeared. I also tried setting M207 Z(random number) and after starting a new print, Z=0 is at a height of (random number) and actually you can jog the nozzle into negative numbers after stopping the print...and it goes right to the negative height of M207 Z value.

This seems like a bug in the firmware as Zhop height doesn't get cancelled after the print finishes without unretracting.

p40whk

@randomfactoid So I just checked and don't have G10 anywhere in my code and am not using M207 yet I still have this issue. So, my problem even though related does not seem to be the same.

RandomFactoid

@p40whk what values does M207 return ?

p40whk

@randomfactoid said in Mid Air Prints unless I Restart:

@p40whk what values does M207 return ?

I'm in the middle of a print right now, where/when would I use the M207 command?

RandomFactoid

Overall - at any point, but it'll probably be hard to see the output while printing. Although try that in console - it might work.
Tbh your issue sounds exactly like mine, but, you're right, it's different if you aren't using G10 anywhere.

Phaedrux

@p40whk said in Mid Air Prints unless I Restart:

@randomfactoid said in Mid Air Prints unless I Restart:

@p40whk what values does M207 return ?

I'm in the middle of a print right now, where/when would I use the M207 command?

M207 sets the parameters for firmware retraction. If you haven't set it up in the slicer to use it, it won't tell you anything. If you were using it, you'd know.

p40whk

@phaedrux said in Mid Air Prints unless I Restart:

@p40whk said in Mid Air Prints unless I Restart:

@randomfactoid said in Mid Air Prints unless I Restart:

@p40whk what values does M207 return ?

I'm in the middle of a print right now, where/when would I use the M207 command?

M207 sets the parameters for firmware retraction. If you haven't set it up in the slicer to use it, it won't tell you anything. If you were using it, you'd know.

That's kind of what I thought, it's not set up in my slicing program.

I'm waiting for the first print to be done and I'll take a video of what it does when I go to print a new print.

jasperkm

@p40whk could you check if there is a G10 command at the end of the .gcode file that you're running? (just before the end gcodes will run)

p40whk

@jasperkm said in Mid Air Prints unless I Restart:

@p40whk could you check if there is a G10 command at the end of the .gcode file that you're running? (just before the end gcodes will run)

0_1550429099237_3030_filament_guide_v2.gcode

I've attached the file I'm currently printing. Checked a few others as well and there is no G10 command present.