[FIXED] Bridges not generated

[payala]

Hi All,

I'm having an issue where bridges are not recognized in the print. You can see the model in the preview mode of S3D, with the coloring set to "feature type":

A close-up from below of the bridged sections reveals that no bridges are detected:

Neither from above, obviously:

You can find the model here: http://www.thingiverse.com/thing:10398

Any clues?
Best regards,

[andrewk72]

Those perimeters are already going to be printed in the correct orientation, so it probably doesn't need to do bridging for that space

[payala]

Not really, you can see in the picture what happens:

And the printed part shows that many of the bridges are not correctly joined to the two helix bodies. After all, bridges are needed for a reason.

[dkightley]

Not sure about the bridging.....but here's what to do to sort out the apparent non-connection of the horizontal bars to the spiral tube.....

On the Mesh dropdown, select the Separate Connected Surfaces option. This will generate several extra items in the models list. Then go to the Other tab of your FFF settings and enter a Horizontal size compensation of 0.1mm.

The model consists of multiple meshes that don't overlap...they just touch. The Separate Connected Surfaces option breaks the model down into separate meshes....and the Horizontal size compensation makes the now separate objects actually overlap. And the slicer does the rest!

Personally, I think the bridging is not kicking in because the gap area is not large enough to trigger the bridging routine....and I think also that bridging doesn't operate on perimeters, and most of the bar is made up of perimeter.

[JasonA]

Hey Doug!

I wish I could rate posts because I've been trying to print one of my parts from SolidWorks for the last day or 2 and trying to figure out WTF is going on with the super small gap or area between my regions on my part. Driving me nuts until I just read your post!

Tried it and now the slicer shows one solid part!

Thanks for the tip!

[payala]

Hi Doug,

Your trick definitely did the job, I'm not sure how did you figure that out, but it's quite impressive.

I just have one question remaining, when I expected to have a bridge, I didn't mean on the small gap, I expected the lower layer of all the horizontal bars to be done as a bridge. Am I wrong to assume this? Why are they not printed as a bridge?

Thanks a lot for the tip,
Pedro

[jimc]

its not bridging because as doug said for some reason s3d doesnt do bridging for perimeters and what you have there is just perimeters. this has been brought up a few times in the past. if those were wider surfaces for instance, the perimeters would be shown in blue but then the solid infill between would show up in yellow as bridging.

[dkightley]

Thanks for confirming that, Jim.

[S3D-Jason]

I'm happy to say that this option has now been added in Version 4.0. You can now choose the exact settings that are used for the perimeters that are bridging across the model. You can enable this option on the Other tab of your process settings by checking the "Apply bridging settings to perimeters" option.

I tested the model that was posted at the beginning of this topic, and the bridges across the center are now printed in yellow as a bridging region if you enable this option.

Thanks for reporting the issue!