Failed ABS Print

We had a major failure on a print we left to run overnight. It looks like the print started to fail and then at some point the head lost its position and started grinding into the print bed far away from where the print was to occur. Has anyone seen something like this, if so, what could cause this. We had used the CuraABSFine profile with 70% infill.



stl file:
PullTrim Bottom.stl (12.4 KB)

I have never seen that occur. It’s almost like it reversed direction on both Z axis motors mid print. The offset to the side is probably just due to the belts slipping when it hit the print, but the reversal of Z direction is weird. It’s set in firmware, and it’s set per motor on Z, so whatever happened had to have inverted both motors on that axis at once. The only thing I can think of is if someone or something accidentally managed to figure out what a reverse motor command would be, typed that into the control software (maybe by stepping on the keyboard?) causing the head to eventually crash.

You’ll want to replace that PET sheet with PEI or BUildtak since you have to replace it anyways now.

Does your printer seem to respond normally to Z axis move commands, or is it still reversed?

Was the part sitting under the bed? maybe it thought it had a section under the surface of the glass it needed to print?

The prints are run from the SD card, no computer / keyboard is connected.

I can move the Z axis using the control “Move Axis” and it does move in the correct direction.

The part was not under the bed, verified this on the stl file and gcode.

post the gcode also please.

Here is the zipped .gcode file.
PullTrim Bottom.zip (6.96 MB)

Thanks.

I’ll look into it tonight as i’m sure others will also.

The other thing that is wierd is the patern on the gouged out section of the bed doesn’t seem to match any part of the STL file. There should be a valley in the middle getting progressivly deeper as it goes up the part and no notches on the wings. It almost looks like it started a new part. Is there something stored on that SD card that looks closer to that profile than the one it was supposed to be printing?

My thoughts exactly. That’s why I asked for the gcode. It would appear from the photos that there is a “missing” part of this puzzle. The way the film is torn doesn’t match up my expectations either.

Initial impression is that there is another part that was removed and not pictured. The part depicted doesn’t seem to have been printed where it sits. The first layer of the part is squashed a lot and the squashing seems to exacerbate on the Z+ direction. It seems to me that there was binding or or some other mechanical issues that stopped the Z axis from moving up.

Disclaimer:

I’m at work and haven’t looked at the stl or gcode yet.

I seem to remember someone awhile ago that had issues with their SD card that retained parts of prior models. They had to use a new SD card to resolve the problem.

The actual gcode looks fine (see my comments below) As does the stl file. The part of the model that printed seems to be part of the upper sections of the model but it appears to be laying on the print bed upside down? is that right? At this point, I’m leaning more toward a hardware issue. It would seem as though the machine didn’t home properly.

as for the gcode, there are no provisions implemented for the bed and extruder to heat up prior to printing. They are commented out. I assume you have been preheating manually? I’d suggest using software control for manipulating the heaters.

;M190 S0 ;Uncomment to add your own bed temperature line
;M109 S0 ;Uncomment to add your own temperature line
G21                     ;metric values
G90                     ;absolute positioning
M82                     ;set extruder to absolute mode
M107                    ;start with the fan off
G28 X0 Y0               ;move X/Y to min endstops
G28 Z0                  ;move Z to min endstops
G1 Z15.0 F10500;move the platform down 15mm
G92 E0                  ; zero the extruded length
G1 F200 E0              ; extrude 3mm of feed stock
G92 E0                  ; zero the extruded length again
G1 F10500      ; set travel speed
M203 X192 Y208 Z3       ; speed limits
M117 Printing...        ; send message to LCD

Looking at the gcode with http://gcode.ws/ the .STL and the gcode do not match the print in the picture.

Has that print been removed and cut at? It doesn’t look adhered to the surface and has a white border similar to how black ABS looks after cutting off a raft.

Disregarding that, I had something similar happen to me today, it was only on the first layer infill when I caught the cable, so quickly I heard the fan dip a bit but when I looked round the print head had moved over into the one of the corners, well away from the actual print, and started randomly carrying on the infill in the middle of nowhere, although it wasn’t cutting in to the PEI.

I’ve noticed that when you power off the machine quickly, after turning it back on until you actually home an axis the printer treats the position it was turned off at as home. Perhaps a rapid power surge/drop could have sent the printer a bit mad with nobody watching to correct it, although you’d have thought the Z stop would have prevented it from digging in like that, the only reason I could think it wouldn’t was if the bed was really out of level.

This part is the only file currently on the SD card. It was a brand new card prior to this print.

The part was printed in the center of the bed, It was removed and the brim taken off. I placed the part back on the bed approximately where it had been printed.

Yes, the part was removed from the center of the bed and the brim was removed. I placed the part back on the bed in its approximate print location. The print was not in the location of the table gouging.