Trouble with slicing an object

[jccdesign]

Hi im designing a lamp fixture and made the 3d model , wanted to print a scale model , but when i preview the slicing it appears its creating gaps in the slicing . What could be the problem .

[jimc]

you will need to post up pictures of what your talking about. a screen shot of the preview.

[Dale Reed]

jcc,

Any place in the design that's thinner than your extrusion width will result in a gap. People have this problem when the design vases and such. Try making the outer shell thicker. (You'll need it to be thicker anyway to support a lamp and shade....) I'm guessing that when you scaled the item down to print a "scale model", you scaled the thickness of the shell down to something thinner than what the printer extrudes. (In S3D, with an 0.35 mm nozzle and typical filament diameter and extrusion multiplier, the extrusion thickness is 0.43 mm - ish. Part needs to be at least that thick everywhere.

Unless I'm mentally visualizing that all wrong. In that case, please attach a screenshot from the slicer and/or an .STL file (zipped) and process settings (.FFF file exported from S3D, for example).

Dale

[jccdesign]

you will need to post up pictures of what your talking about. a screen shot of the preview.

ok , let me see if i can attach the file,

[jccdesign]

i checked the model in netfabb and there was no problem with it, the model is a solid mesh , so why it isnt treating it like if it was a vase, in the 3d model the walls were .125" thick (3.1 mm) aprox

[Tim]

It's still sort of hard to see what's going on in the S3D gcode preview, but I would point out that there are known problems with the S3D slicer. It is better than other slicers, but occasionally you will come across geometry that it just can't slice right. I can't really tell if this is one of those cases. The errors I've seen or heard about all appeared to be caused by concentric filled areas, where S3D got confused and started filling the gaps in between the solid parts instead of filling in the solid parts.

[jccdesign]

Yeah basically is just starting to fill areas in the air , instead of following the geometry of the object.

[jsc]

The regions where the walls cross in an X pattern, they look thin. Are you sure they are thick enough in every layer to fit your filament thickness?

Try slicing at a ludicrously thin layer height with an unprintable filament thickness, like .1mm each, to see if that works.
Then try using a different slicer with your same settings, to see if it is a slicer issue.

Also, your design may or may not turn out to be printable; some of those overhangs look pretty severe.

[Tim]

I have heard from others that adjusting the 1st layer height can cause S3D to stop misbehaving. The theory is that it's just some numerical error, and by changing the height, all the numbers change, the calculations are all different, and the error goes away. Maybe. I haven't had much luck with that. One of my prints that S3D insisted on filling in white space on was never right, no matter what I changed.

You might try running it through slic3r. Poor toolpaths trumps great toolpaths with completely hosed geometry.

[jimc]

i agree they look too thin. i realize the wall of your object may be .125 BUT the holes go into your model at angles which means that the wall thickness at that particular layer may not be thick enough. as dale and jin said, your printer can only print so small. s3d knows this so anything smaller it simply wont accept. like jin said, for test purposes lower your extrusion width down to .1, slice and see what the preview looks like. if it looks better but not perfect then lower it even a bit more. dont print this way but you will be able to confirm this is the problem.