Top layer fill shadows?

[Russ]

I'm running into a problem printing the top layers if there are standoff pillars on it. When doing the top fill it seems to skip the filling in the "shadow" of the standoff pillar. It fills as you would expect until it comes to a pillar. It fills up to the pillar, then moves past it continuing to fill in the rest of the level but it never goes back to fill in the area it skipped. It only happens on one side of the pillar depending on the direction of the fill. It happens on each layer of the top layers. I'm at a loss since both the model and the preview look like they should a nice flat surface. Looking at the relevant layers in the preview also look nice and flat without these non-filled in area. Any ideas?

Image of part

Preview Screen Shot

Model Screen Shot

[JoeJ]

The preview looks correct to me. And it looks like it DID print those shadow regions in your picture, they just have a slightly different texture than the rest

[Vasily]

Maybe hardware problem?
try check belt tension on each axis

[Russ]

It has 5 "Top Solid Layers" the first 4 have surface area's where it didn't fill. I watched it print so I saw this first hand. The final layer printed completely but the surface is uneven since the 4 lower layers have swaths with no material. I reprinted it using Cura and it printed without any of these artifacts.

[JoeJ]

What printer is this? Why don't you post the factory file for others to try? Should be pretty easy to know if it is a hardware problem then

[Russ]

I'm using a Printrbot Simple Metal with heated bed. Here is the Factory and stl file for the part.

[SockMonkey]

I'm using a Printrbot Simple Metal with heated bed. Here is the Factory and stl file for the part.

i took a look at your factory file and I think I see what you're talking about. It may be due to the transition from the base to the actual standoffs and the standoffs having thin walls and your process using 3 perimeters (not good for thin wall printing). in the advanced tab, enable allow gap fill up to 50%, in the infill tab, change the outline overlap to 40%, and then in your layer tab chagne the perimeter to 1. If you want more perimeters on the base you can set up multiple processes.

[Russ]

Thanks, I'll give that a try. I've already made the standoffs thicker and extended them 1mm into the base. It printed much cleaner but still had a few voids, luckily those will be hidden under pc boards.

[smartavionics]

I think this could be related to something I posted about a little while ago which is that when you put something on top of a outer layer (in your case pillars, in my case it was raised text), s3d tries to extend the lower infill into the raised object rather than just putting the raised object on top of unbroken outer layer(s).

Obviously, if the raised object is large then it makes sense for the lower infill to meet the infill within the raised object but for small objects I don't think it works well due to the resulting poor quality of the outer layer due to the fact that the outer layer is not solid below the raised objects.

Cheers,

mark

[dkightley]

I concur. This is a deficiency in the slicing, which I believe is the same as the following two issues:

http://forum.simplify3d.com/viewtopic.php?f=23&t=1809

http://forum.simplify3d.com/viewtopic.php?f=9&t=2086

I've taken a close look at the print simulation for the op's part and you can see the layer-by-layer slicing progress here. These follow a layer that's just the infill: