Hollow Sphere Bridging Issue/Question

[Erutan409]

So, I'm kinda lost for how I should attack the issue I'm having. I'm trying to save on material and decided to hollow out a print with Meshmixer (that part went ok). I'm trying to adjust my settings at different heights (multiple processes) and I'm not sure how to correct my settings to prevent S3D from printing in mid-air with no surrounding attachments as shown in this screenshot:

It gets noticeably worse as it gets closer to finishing off the top of the print, too:

I'm using the following settings for bridging and have tried removing it entirely by increasing unsupported area threshold to 200. However, doing that didn't seem to disable bridging. So, that's even more confusing to me.

S3D version: 4.0.1

[DarthRevan]

At the very least, you're going to want supports for the perimeters that are just printed in air inside the sphere. This will lead to not a ton of filament saved by your hollowing of the part, but it'll help there be something firm in the middle for your solid layers to bridge between.

I'd use at least 3 layers of dense supports and at least 2 perimeters. Auto generate supports should pretty much fill up the inside of the sphere for all areas where this'll be needed. If it doesn't I'd try reducing the support pillar resolution so it captures smaller areas that need supported.

[Erutan409]

At the very least, you're going to want supports for the perimeters that are just printed in air inside the sphere. This will lead to not a ton of filament saved by your hollowing of the part, but it'll help there be something firm in the middle for your solid layers to bridge between.

I'd use at least 3 layers of dense supports and at least 2 perimeters. Auto generate supports should pretty much fill up the inside of the sphere for all areas where this'll be needed. If it doesn't I'd try reducing the support pillar resolution so it captures smaller areas that need supported.

Thank you for that suggestion. Adding the larger perimeter definitely seemed to help with what I was describing. However, I opted not to go with the supports (which is why I was attempting to leverage the bridging functionality). The auto-generated supports added about 400% to my overall print time.

[DarthRevan]

There is always a balance of printing time and quality results with desktop 3D printing. So if the exterior finish is to your liking and you don't need to use the supports, go for it!