Heater error mid print - how to restart

jens55

I have an 11 hour print job (yeah, of course it had to be a long one) and about half way through, a heater fault occurred.
Unlike a filament out error, there in no obvious 'resume' print option .... why ?
Is it hiding someplace ?

I tried messing with the example resurrect-prologue.g file but just got a LOT of ejected filament (the heaters were reset and turned back on by me) followed by a lot of bouncing against the X stop.
All axis are now un-homed so likelihood is that I am out of luck but it would be real handy if I was aware of what to do should this happen again.

Phaedrux

If you pause the print, it should save the resume state.

But it would be helpful if it saved the state in the case of a heater fault as well.

I've been able to resume prints in cases like this by finding the height of the model at the last printer layer and then reslicing the model cut so that only the remaining portion is sliced and then manually resuming. I usually manually home the Z axis by touching the nozzle to the print and sending G92 Z0 and then starting the print. You may need to edit the gcode file to remove any preamble gcode.

jens55

hmmm ... without thinking it through, it would seem that we already have the code in the software to do everything. Just do the same thing as is already done in the event of a filament out message - park the head and pause until the operator can fix the issue.

dc42

@jens55 said in Heater error mid print - how to restart:

I have an 11 hour print job (yeah, of course it had to be a long one) and about half way through, a heater fault occurred.
Unlike a filament out error, there in no obvious 'resume' print option .... why ?
Is it hiding someplace ?

I tried messing with the example resurrect-prologue.g file but just got a LOT of ejected filament (the heaters were reset and turned back on by me) followed by a lot of bouncing against the X stop.
All axis are now un-homed so likelihood is that I am out of luck but it would be real handy if I was aware of what to do should this happen again.

If you notice the fault early enough, you should be able to reset the heater fault using M562, bring the hot end up to temperature again, and resume the print.

If you don't notice it early then the print will be abandoned. If you've previously set up and tested your resurrect-prologue file, you should be able to resurrect the print using M916.

jens55

I discovered the error with everything still hot, just dropped a few degrees. I did reset the heaters and got them going again but there was no 'resume' option like there would be if the print was paused from for example a filament out error.
How do you resume the print?

On a related note, My attempt at reprinting the model got me to 80% this time around before the filament ran out (over night). This would be all fine if there wasn't a hook in the filament where it hooked into the empty spool. The hook caught on the filament out detector and prevented the 'filament out' signal from being raised. I am not a happy camper this morning
Would the Duet magnetic filament out detector have shut down the printer successfully under these circumstances ?

Phaedrux

@jens55 said in Heater error mid print - how to restart:

How do you resume the print?

M916 should do it.

https://duet3d.dozuki.com/Wiki/Setting_up_to_resume_a_print_after_a_power_failure

Phaedrux

@jens55 said in Heater error mid print - how to restart:

not a happy camper this morning
Would the Duet magnetic filament out detector have shut down the printer successfully under these circumstances ?

Ideally yes it should detect that no filament is moving and pause the print.

I had a similar situation the other day where someone bumped the spool and it came off the hub bearing enough that it eventually caught. I didn't notice for several layers. I really should give the laser filament monitor I have another try.

jens55

The laser unit is supposedly sensitive to different filaments so I am not enthusiastic to try it but the magnetic unit, if it would prevent this sort of thing, would be a worthwhile upgrade.
If the spool is almost empty, I usually unwind it and cut the end off before it gets to be an issue but this print is 500 gr and runs over night so that was not possible. There was also no access to the end via the spool mounting hole.

jens55

@Phaedrux said in Heater error mid print - how to restart:

@jens55 said in Heater error mid print - how to restart:

How do you resume the print?

M916 should do it.

https://duet3d.dozuki.com/Wiki/Setting_up_to_resume_a_print_after_a_power_failure

This assumes that you are set up - I wasn't. I did try to set up after the fact but I was not successful.
Again the question needs to be asked - why not just pause the print as if it was a filament out situation. It might require shutting down the heater that caused the fault and if it was the bed the print is likely lost but if it is the hot end then it would be very simple to just restart.

dc42

@jens55 said in Heater error mid print - how to restart:

I discovered the error with everything still hot, just dropped a few degrees. I did reset the heaters and got them going again but there was no 'resume' option like there would be if the print was paused from for example a filament out error.
How do you resume the print?

A heater fault pauses the print, so the Resume option in the Status page of DWC should be enabled.

jens55

Hmmm ..... don't know what happened then because there was no option to restart.
If it happens again, I have a few things to try. So far everything is going as it should (I unplugged and re-plugged all connections)

Thanks for all the help!

jens55

I figured out what was happening. The power cable to the heater was in the process of failing from flexing. Once it failed completely I was able to diagnose the issue. I also saw that I had the opportunity to reset the heaters and restart but after 600 seconds that option goes away and restart isn't possible any more.
Question - is there any way of changing the timeout value ?

wdenker

@dc42 Has this changed at all? It would be nice to have it pause and only stop heating the heater that faulted not the bed. Can this be changed somehow? Also if it was a true pause instead of timing out and going away after so long would be awesome as well. Most of the time the print stops in the middle of the night and I don't wake up early enough to get to it. I don't see any reason for making it time out or having the other heater stop.