A whole section of my model is just disapearing

[joealarson]

So here's a weird one. I have a huge model, a little more than 12"x12", that when I slice it the whole bottom part disapears, and the top part is just hovering in space. I've attached the model here. I have some theories, and I'll check back here when I know more, but I wanted to document the problem here. Slic3r also has a problem with the model.

[dkightley]

I've just loaded your stl into one of my profiles....and apart from it being too big for my printer, it slices okay.

Suggest you attach the factory file so others can see how your profile fails to slice.

File menu...+ Safe factory file. Have the stl & your profile loaded before saving.

[joealarson]

Okay, I think I got it. Those huge side walls I think are too big a polygons to succeed in the layer intersect test. I don't know if there's a problem with roll over in the floating point math or something (And yes that is a thing because floating point math isn't infinite, it's just floating so it seems that way), but to test it I scaled up a cube to 400x400x10 and it too disappears, though if I do it 399x399x10 it suddenly reappears.

...okay, this is odd. As I was typing this I was playing around with the numbers and the box is appearing and disappearing in an odd way. To get my huge box I'm taking a 1mmx1mmx1mm cube that I keep around and scaling it up with the scale factor, so I type in a scale factor of 40000 to get my 400mm box. But if I type in 400 for the box size S3D reports a scale factor of 40000.01. Here's where it gets odd. scale factor of 40000 and the box is gone, but scale factor of 40000.01 and the box is there. Scale factor of 39900 and the box is gone, scale factor of 39900.01 and the box is there.

At this point I leave this in your hands. No idea what the problem is.

[joealarson]

I've just loaded your stl into one of my profiles....and apart from it being too big for my printer, it slices okay.

Suggest you attach the factory file so others can see how your profile fails to slice.

File menu...+ Safe factory file. Have the stl & your profile loaded before saving.

Well, I would, except that suddenly is't slicing fine. I swear it wasn't this morning, but now it is. The cube is still a problem, but it's intermitant. I'll attach that FFF file in it's failing state here.

[dkightley]

At this point I leave this in your hands. No idea what the problem is.

Just so you're aware.....I'm a S3D user....not a representative of Simplify3D....so leaving it to me is not appropriate!

[horst.w]

So here's a weird one. I have a huge model, a little more than 12"x12", that when I slice it the whole bottom part disapears, ...

thats only why your model is situated to deep in the space (problem of your CAD)
Dobble-chlick on lift up by using Z-Offset or use Edit > Drop down to .. .. and Center and Arrange which can be also pre-set in Tools > Options

[horst.w]

Your Factory-File has a big problem concerning a scale to 40,000 (fortythousand) %;
while using 1,000 % it will be a roundabout 10 mm cube and 100 % reduce it to a 1 mm cube.

I think that is a missmatch with feet / inch / meter / centimeter coming out of your CAD and please notice that a STL-File doesn't contain any dimension values .

With check or uncheck the box in Tools > Options > Models you can get different results, otherwise dobble-click to the object and minimize the scaling value.

Regards
horst.w, GER