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Mysterious Stoppage

Posted: Sat Dec 16, 2017 4:46 pm
by Gwhite
I was running a job last night, and after printing 3 objects sequentially, it got to the 4th and just froze about 1/4 of the way through. The heaters were still on, but all the motors stopped. No motion & no filament feed (other than a bit of oozing...). I print from an SD card using the LCD interface, and have a switch to disconnect the USB cable from the computer to avoid crashes when the computer hiccups or goes to sleep.

The preview in S3D looks fine. I re-created the file and am running it again to see if it repeats.

It can't be a power outage, because both the heaters were still programmed & running at the desired temperatures.

Any idea what could cause this? I'm baffled.

Thanks!

Re: Mysterious Stoppage

Posted: Sat Dec 16, 2017 9:46 pm
by insta
I've encountered this a few times -- it's some kind of firmware hardlock in newer versions of Marlin.

Cue Ed...

Re: Mysterious Stoppage

Posted: Sat Dec 16, 2017 10:36 pm
by Gwhite
The second attempt ran fine, so it's not the file.

My headache at the moment is that a very minor tweak to the model has broken sequential printing. A single model slices & prints fine, but if I try to do more than 1, Simplify3D hangs while calculating the infil. I have to close the program to escape. I've posted a query to the S3D forum in the hopes there is a fix. I need to print ~ 50 brackets, and doing them one at a time will take me a week or more...

Re: Mysterious Stoppage

Posted: Mon Dec 18, 2017 2:20 am
by willnewton
Do they have to be printed sequentially?

Will it work if you create a single file with multiple STL models laid out to match the print bed? We’ll just say half a dozen parts in one STL file.

Import and print the single file in S3D that contains the half dozen parts.

Re: Mysterious Stoppage

Posted: Mon Dec 18, 2017 2:28 pm
by ednisley
Gwhite wrote:The second attempt ran fine, so it's not the file.
Opinion, not fact: a timing issue (*), deep inside Marlin, killing the path planner.

For example, the version I'm using sometimes never emerges from the "wait for temperature" countdown before the print, despite all the temperatures being Just Ducky. There's no obvious cause or dependable cure.

It's enough to drive one to Update The Firmware to see if the recent flurry of bugfixes and code refactoring has any positive effect, but I'm not there yet.

(*) Which is why depending on the printer's firmware to catch overtemperature problems is a Bad Idea. In your case, the temperature regulation continued to run, but that's not the way to bet.

Re: Mysterious Stoppage

Posted: Mon Dec 18, 2017 11:03 pm
by Gwhite
willnewton wrote:Do they have to be printed sequentially?

Will it work if you create a single file with multiple STL models laid out to match the print bed? We’ll just say half a dozen parts in one STL file.

Import and print the single file in S3D that contains the half dozen parts.
The "clear" filament I'm using really wants to be printed one model at a time. It's hard enough to get a vaguely transparent result printing them sequentially. I've got my fan turned off, and when the extruder comes around for the next layer, you really want to have the previous layer as warm as possible to get things to fuse together.

Re: Mysterious Stoppage

Posted: Mon Dec 18, 2017 11:54 pm
by zemlin
If S3D hangs while calculating infile, there's probably an issue with the STL file. Check the repair options in S3D. You might try exporting the STL with different precision settings to see if you can get a clean file.

Re: Mysterious Stoppage

Posted: Tue Dec 19, 2017 3:16 am
by Gwhite
zemlin wrote:If S3D hangs while calculating infile, there's probably an issue with the STL file. Check the repair options in S3D. You might try exporting the STL with different precision settings to see if you can get a clean file.
I considered that, but it printed a single model just fine. It turns out there is a bug in S3D 4.0 that causes this behavior, and it's been fixed in version 4.01. That all works fine now. The mysterious stoppage in mid-print is presumably another matter.