Issue with support materials on horizontal surface

I am having a problem with generating support material for horizontal surfaces in Slic3r version 1.2.6.





I created a test model to demonstrate the problem. It is a box with a central horizontal plane (red) and two fillets. When I slice with overhang thresholds of form 1 to about 20 I get support generated for the fillets but not the horizontal plane. I have attached the STL and slicer preview. Parameters:



Any thoughts appreciated. I did a workaround in CAD to resolve problem.

Perhaps you have to disable bridge detection. The horizontal plane is considered as doable with bridging capabilities supported at the two end by the support for fillets.

Quote
3Dmaker4U
Perhaps you have to disable bridge detection. The horizontal plane is considered as doable with bridging capabilities supported at the two end by the support for fillets.

I think that is the explanation. A horizontal area is a bridge and not an overhang, and I would normally not want supports under a bridge unless it is very long, in which case I add them in the design. S3D puts supports under bridges - but it allows you to remove them (IMO it is by far the best slicing application for items that require supports).

Dave

Thanks 3Dmaker4U, turning off don't support bridges under support material tab fixed problem. I've had this problem before and its good to know there is a simple solution once you know the answer. Wish this was documented on the WIKI under support material.

Roger