What's going on in this print?

Hi,

I'm trying to print some calibration objects from thingiverse including this "hollow cube." (pics attached). There seems to be some weird stuff going on. In picture one, you can excess strings of filament. It happened when the bridges were being formed. On the second picture you can see a surface artefact that I've had in all my prints so far but never this clear. The cube was sliced with skeinforge 0,2 PLA profile. The only settings I've changed were infill solidity ratio set from .25 to .10. And solid surface thickness from 5 to 3. I don't know much about skeinforge but I thought the lowering of these settings would spare some filament and make the print duration a bit shorter.

Any ideas what's going on?

Hi,

It is probably a little early to start changing infill solidity and solid surface thickness values.

There looks to be an excess of filament being extruded. I would re-check your Extruder Steps per mm calibration. I had similar effects to what you see here before I got my calibration spot-on and started using cooling effectively.

The patterning on the outside of the print is where the end-of-layer filament meets with the start-of-layer filament. Any excess of material being extruded seems to exaggerate this effect.

Regards,
Neil Darlow

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I try to write with consideration for all nationalities. Please let me know if something is unclear.
Printing with Mendel90 from fedora 25 using Cura, FreeCAD, MeshLab, OpenSCAD, Skeinforge and Slic3r tools.

Skeinforge only handlies bridges in one direction per layer so on the layer with bridges in two directions at right angles it looks like it is doing normal diagonal infill that just falls down (having nothing to attach to) giving the loops.

If I was designing that object to be printed I would have one layer difference in the position of the X and Y bridges so skienforge could bridge them properly.

Reducing the solidity and the number of solid layers is likely to give a poor top surface. As the layers get thinner it takes more solid ones to become flat.

The surface artefact is where the filament starts and ends on the outline. It is had to tell from a photo but it looks a bit hot. Are you using 185C as the supplied profile?

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[www.hydraraptor.blogspot.com]

Hi Neil and Chris, thank you for the replies. I've made sure that my extruder is calibrated to the best of my ability using the filament measuring procedure mentioned in the manual. But I now understand that the stringing is caused by the design of the object. That's one worry less then. As for the temperature of the filament, how can I verify that 185 C is used? I used the supplied profiles for Skeinforge. On the temperature tab I see temperatures mentioned that are no less than 195. Ranging up to 230 C. Might this be the culprit?

Thanks in advance,

Niels

If you are using Nophead's Skeinforge then temperatures are set in your .skeinforge/alterations/start_PLA.gcode file. The Skeinforge Temperature module should not be active and therefore not apply.

I tried printing that cube and, as Nophead says, the problem appears to be with the object design because I experienced the same result. I have done simple unidirectional bridges without any problem using the PLA0.2 profile.

Regards,
Neil Darlow

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I try to write with consideration for all nationalities. Please let me know if something is unclear.
Printing with Mendel90 from fedora 25 using Cura, FreeCAD, MeshLab, OpenSCAD, Skeinforge and Slic3r tools.

You should see the extruder temperature and bed temperature reported during the warmup sequence.

Other slicers can print that object because they don't have the limitation that all infill is the same direction on each layer.

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[www.hydraraptor.blogspot.com]

Ok I think the temperature at the beginning always shows 185 during the countdown before the start of a print but I'll check the temperature during a print with the check temp button

Edited 1 time(s). Last edit at 10/30/2013 03:36PM by Nilez.