michael.t.albers wrote:

looking at the pics, I think the reason for the split is how thin the plastic is on those sales.  One way to prevent this is to run the extruder 5 degrees hotter.

I don't think that is it. I did this print prior at at 1/2 size and it completed without spliting. It was a bit stringy, but the layers stayed together.

but it was one half the size = one half the stress, on probably the same cross section of wall.

also, different colors of filament have different temperature response. your issue might be because you went from a heavily pigmented green to a totally unpigmented natural. just a thought.

looking at the pics, I think the reason for the split is how thin the plastic is on those sales.  One way to prevent this is to run the extruder 5 degrees hotter.

I don't think that is it. I did this print prior at at 1/2 size and it completed without spliting. It was a bit stringy, but the layers stayed together.

A lot of people have, but it seems like the kind of prints they do are flat things like signs, keychains, etc.  The cracking you got is usually due to a wider temperature difference across the height of the print, so letting the hot air out seems like a good possibility.  If you actively heat the inside with something like a small space heater, then that might minimize the effect of opening the enclosure.  You could also try printing it without the enclosure.  If it is something that would succeed in the open, then you wouldn't be changing the conditions when you go in to change filament.

Cool, thank you.

well, i think it might be a bit inconclusive.

I'd consider upping the flowrate by 5-10% on the first layer after a new roll. That way you can squish the filament a bit more down.  This might make the connection stronger and ensure any minute error on Z is compensated for.

But it looks like that piece might already have a lot of warping stress and at that height it was possibly going to peel anyway, since it was getting more thin on a few of the walls. The connection with the filament could be that there is a stress concentration on where you change the filament, and that's probably going to exist no matter what. There will be *some* discontinuity of strength at the new filament.

I'm not sure, I wonder if others have more advice or ideas

Next time I try to continue on to another filament I'll try to flow more of it through before continuing to print. Make sure the color change is complete and the temp is back as hot as it was. I hope someone else has had some success between rolls.

I'd consider upping the flowrate by 5-10% on the first layer after a new roll. That way you can squish the filament a bit more down.  This might make the connection stronger and ensure any minute error on Z is compensated for.

But it looks like that piece might already have a lot of warping stress and at that height it was possibly going to peel anyway, since it was getting more thin on a few of the walls. The connection with the filament could be that there is a stress concentration on where you change the filament, and that's probably going to exist no matter what. There will be *some* discontinuity of strength at the new filament.

I'm not sure, I wonder if others have more advice or ideas

As the well-known newbie I offer this for what its worth. But my guess would be maybe the heat loss when you opened the enclosure and changed filaments took a minute to sink in, a thermal flywheel effect. When it did, the colder filament didn't join well.  The layers above it were laid down when the heat came back up and the cooling filament pulled the weak striation apart.

If that be the case should I close the enclosure after the new plastic is loaded and let it sit there for 5 minutes or so for the heat to fill back in there? I would of course need to turn the hot-end off as to avoid clogs, but the bed would still heat the area up?

I was afraid it was an issue with the properties of different colored ABS. I've not seen too many examples of successful transitions.