"curling" edge

[BlackCloud 1]

Early in this print this edge starts to curl up. I really have no idea where to start trouble shooting this. I've reduced the temp and print speed, increased fan speed because some thing I found suggested it was printing the layers too fast. Where do I even start? .06 layer height. PLA with PVA support material.

[kmanstudios 1,120]

What are you slicing with? What printer? This looks like the UM PVA and PLA that comes with the UM3 series. I am not sure what the others came with.

 

I am thinking it needs to maybe speed up a bit so the nozzle does not sit too long over an area. Fans at 100%? Temp on PLA? I find, in my environment, that 195°C works well for most of my  PLA choices.

[BlackCloud 1]

Oops. Forgot to include slicer and printer.

 

UM3 with latest firmware update. Cura 3.2.1

 

PLA temp is set at 210. Fan speed is 75%/100% max. Print speed is 60m/s

[kmanstudios 1,120]

I would try cutting back on the temp. The curling comes from the heat being there too long and the edges cooling faster. Also, make sure that your buildplate volume does not stay hot either. Maybe even cut back on buildplate temp to keep volume from holding too much heat.

[BlackCloud 1]

Worth a try. I'll let you know how it goes.

[geert_2 557]

On my UM2 (=single nozzle) I also have this when printing overhanging edges. They do curl up as they cool. Overhangs are not very stable anyway, since half of the extruded sausage is printed in the air, without something to support it (at least in single nozzle printers like mine). So, as long as it is flexible, it is likely to curl, in this case curl upwards due to shrinking. Small models suffer from this more than big models, due to less cooling time per layer.

 

The best solution for me was to provide way more cooling: put a desktop fan of 30cm diameter in front of the printer, and set it to its lowest speed. So that the heat is evacuated fast enough from the print. But not so much that the nozzle and bed have problems keeping their temperature. Of course, printing as cool as possible (and thus also slower) also helps, since that makes the new layer cool faster, and it is less liquid when deposited.

 

[BlackCloud 1]

This does seem to be an overhang issue. I've set the cooling fans up to max. Perhaps setting the minimum layer time higher?

[geert_2 557]

In my experience, minimum layer time causes other issues: this reduces the flow rate, so the plastic stays longer in the nozzle and thus becomes hotter and more liquid, which to some degree tends to destroy the desired effect: getting more cooling. The melt gets more liquid, instead of less. Try printing cooler and using the desktop fan first.

 

On an UM3 there may also be issues if there is too much distance between support and model, so the model does not glue well to the support. There has been a recent thread on this and how to solve it (if that would be a cause in your model). But I can not comment on this issua, as I don't have any experience with UM3.