The hell skull

Here is a cool object to print, however, be warned, it crashes on my printer reliably at the same spot. So I'm curious if others have an idea on the cause. My suspicion is the joint where the horns were skulpted into the head, caused an overlapping vertex

Hell Skull on Thingiverse
Here are some images

hellskull2 by thetazzbot, on Flickr
hellskull1 by thetazzbot, on Flickr

The skull should be able to print without support. So I may have something awry in my temps or something else, but where there is a overhang, the plastic dips down. i think its too hot, so too melty.

hellskull4 by thetazzbot, on Flickr
hellskull3 by thetazzbot, on Flickr

Any comments on the texture, layering, or overall print?

Even if there is a problem with the model, the printer shouldn't crash. Are you sure it really is crashing, not just thinking the print is complete e.g. because the gcode file is incomplete? Does the printer response to manual commands at that point?

If it really is crashing, it sounds like a firmware bug to me. What type and version of firmware are you using?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Did you try to slice the skull with a different slicer? One thing which might sound stupid, you could try is, copy the gcode another time to your SDCard (if you are offline printing), with a different name keeping the old (probably broken one) on it. The cause here is that sdcards are incredibly unreliable and on Block on its chip might be unreadable. That might be the reason why it stops everytime at the same spot!

I really recommend you try a different slicer. To save some time you might try slic3r with "combine infill" option.

Edited 1 time(s). Last edit at 06/04/2015 07:58AM by blendmaker.

I'm using Cura slicer in Repetier. It is definately crashing because the first time, the top of the horns were still printed, but offset by 15 cm. thats when the belt was loose. i can see burn marks where the nozzel hit the right edge mid-section, there is that little loop looking thing.

i'm going to try slicr,

thanks

Combined with offset previously and the constant stopping in the same areas I suspect wrong setting in your slicer.
If the stepper motors are driven too fast during infill, bridging or other print moves the printer goes out of alignment.
If you have very rapid print moves in the area where the print stops I would first check the current setting for the motors then the acceleration control in the slicer.
If in doubt try a different slicer and a lower speed in general, if the print works out you know some setting were messed up.
Trying always the same slicer can be useless in some cases
Also make sure the model is free of errors, you can check with Netfab or Blender for example.

How about the overhangs, where it looks very rough and ugly? I'm getting this on other models. I try to change only one variable at a time when I have these kind of issues. In this case, less flow and lower temp had no effect.

You could try to cut that stl in some 3D software where it ended and try to print the rest of the piece separately. Then glue. If it ABS plastic, inexpensive ABS juice and it sticks almost even better than original layers. You could try also fan blowing very faintly or enough to the piece (better quality). Or just sand paper.

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Prusa i3, Ramps 1.4. Catnozzle 0.4mm
SketchUp - Enveloping Globoid Worm Gear - Part One - 3D Printed: [youtu.be]
DesignSpark Mechanical & more precise screw thread: [youtu.be]
Nicer Screw Thread In SketchUp ( Bolts,Nuts): [youtu.be]
How To Model A Heart Shape In SketchUp: [youtu.be]
How To Draw 3D Printable Snap Fit Ball Joint In SketchUp: [youtu.be]

Quote
Plasteroid
You could try to cut that stl in some 3D software where it ended and try to print the rest of the piece separately. Then glue. If it ABS plastic, inexpensive ABS juice and it sticks almost even better than original layers. You could try also fan blowing very faintly or enough to the piece (better quality). Or just sand paper.

Yeah, I have done that trick before. Slicr can do that. Also meshmixer is very cool.

One thing the guy mention in his post is that he printed it without infill or 5% tops, yours look like anywhere from 10 to 15%. Also he used 4 perimeters. Have you tried that way?

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ggherbaz
One thing the guy mention in his post is that he printed it without infill or 5% tops, yours look like anywhere from 10 to 15%. Also he used 4 perimeters. Have you tried that way?

hmmm... no, i think i missed that..

i used 15% on one, and 10% on the other. the 10% one i got bored and dug all the infill out lol. Thought, hmmmm i could put a small jewelry box hinge on the back and print the top of the horns, make an interesting stash box.

I kinda wonder how no infill would work on that... Thanks for the note.

Did you ever find a solution? I tried last night as I went to bed and woke up to this, lol. I used slicer with 30% rectilinear infill printed in pronterface. Thanks

Whatever goes into the horns there is most likely causing the issue on that first one. As for the most recent post others have also noted it dies right above the eyes, there is clearly something wrong with the model. Try running it through netfab first.

Thanks for the info, I'll give it a shot.

Quote
thetazzbot
How about the overhangs, where it looks very rough and ugly? I'm getting this on other models. I try to change only one variable at a time when I have these kind of issues. In this case, less flow and lower temp had no effect.

Try go down in layer hight, a little extra cooling helps too.