Weird bridge first layer pattern

Hi guys! I'm getting a very weird pattern of 1st bridge layer. I'm printing this model, which is basically a square box split into 50 vertical cells with a horizontal "floor" layer in a middle. This requires filling square cells horizontally across the whole box at some point. First of all Slic3r does not generate any support, which might be okay because cell walls are close enough. But for some reason the very first layer is generated not as once monolithic layer across perimeter of the box, but only partially, with some spots where the pattern is inverted. See the Slic3r path visualization below.



Now, all the places where the fill patter was inversed have fallen down and did not connect. See how it looks like:



Any idea why Slic3r generates this kind of filling pattern and how to make it just fill it across the model perimeter???
Thanks!

I would check the Layers tab under Plater to make sure that sections start at one layer. It could be for those parts, the stl isn't flat. You could increase the layer height slightly to see if it changes. I had a part that an extra layer was printed at 0.2, but not at 0.3 layer height.

Edited 1 time(s). Last edit at 06/23/2016 03:11PM by stephenrc.

Slic3r does weird stuff sometimes. Try slicing with Cura.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Make sure that the base of the "floor" starts on an exact multiple of your layer height. e.g. if the floor starts at a height of 12.5mm and your layer height is 0.2mm, it will be starting midway between layers, but if your layer height is 0.25mm it will be on an exact multiple.

Dave

Changing geometrical parameters of the model and re-generated STL and it has helped to some level. I do not get these filling artifacts now but still it would fill up the mid-section of the square floor from wall to wall at approx 30 degree level and then would fill the side triangles in the opposite direction. While not idea, I do not get individual squares to fall through . On a side now, even if floor start in mid layer it should not result in this sort of random fill pattern as it was observed. I think Slic3r algorithm might have an issue here.

Was the model/STL generated in Sketchup?

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

I've the same issue.

There is also an other tread with this issue:
[forums.reprap.org]

Will the problem be fixed in the next version?
I tried older versions of slic3r but it is always the same.

The bridge is at 12MM. I use a layer high of 0,2MM

Best regards,

3d-print-ka

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