27hour print, 3/4 spool ABS and failed thermistor Grrr

[seaton]

I came home today hoping to find a big print nearly finished, well it was but was printing nothing for most of the day today as it looks like I had a failed thermistor which had failsafes the heaters by the firmware, but it didn't stop printing, just turned off the heaters??

anyway it was about 90% through a 27hour print when it failed and has used about 3/4 of a spool of ABS, so as you can gather I don't want to restart it. It looks like it should be recoverable as the thermister must have failed at the end/start of the layer.

I have calculated what layer i need to start at, however the issue is now I've had to turn off my printer to reset the firmware after replacing it so I can't re-zero my Z Axis.

So I thought maybe I can set the Z axis 0 = top of my print, which is fine in theory, this then raises the second issue, how do I slice only a portion of my object so I can continue where I left off, easy simplify allows me to do this by specifying the height I can start printing at (which Ive worked out what layer number it is), so now is where my real problems lies, if I zero Z-axis to the top of my print, and I've got my slicer to only slice what I want to print, how do I make this start printing from Z-Axis 0 and not the true height cause if I start printing it will then want to lower my ZAxis to the correct height?

....well I don't have the answer just yet, but thought someone may know so am putting it out there while I research it a bit more.


Stephen...

[seaton]

...turns out its rather easy to do this.

I offset my model before I slice by the height it currently is then perform the slice.

voila!

now back to my print

[parkview]

Well done on figuring that all out, but...

what where you printing that takes 27 hours 750gm of ABS?

[Jubbp]

I had a similar experience. but my tardis model lifted off the bead so it was a total loss after 18 hrs. Didn't lose a thermister though.

Did it just fail and then come back after a reset? or did you have to replace it?

[seaton]

Well done on figuring that all out, but...

what where you printing that takes 27 hours 750gm of ABS?

Was a Vent Cowling I was printing up for someone, the biggest print I've done so far.

Screen Shot 2014-10-20 at 10.30.15 am.png (93.3 KiB) Viewed 15735 times

Wasn't my Thermistor in the end, looks like it's the newest firmware from Felix has a thermistor Failure sense that decouples the Heaters as a failsafe if it detects a certain temperature rise, turns out it's a little too sensitive grrr and have had to tune things.

[seaton]

I had a similar experience. but my tardis model lifted off the bead so it was a total loss after 18 hrs. Didn't lose a thermister though.

Did it just fail and then come back after a reset? or did you have to replace it?

No I came home and it was merrily doing the print, just so happens the firmware disconnected the heaters about 90% through thinking a thermistor had failed. so no filament was being laid down.

[parkview]

yes, that's a sizable print job there Stephen!

Did you manage to finished off ok?

[seaton]

yes, that's a sizable print job there Stephen!

Did you manage to finished off ok?

No in the end due to the size and being printed in ABS I getting problems with small delimitations on some corners, not huge problems but not perfect.

would have been ok in PLA but the temperatures involved it wouldn't have worked, so had to be ABS

so I put this down as a failed job.

Stephen...