Removing internal patches

[Darthlister]

Hey All,  got a model with a couple of 4-point internal patches that are causing Cura to show it as non-manifold.  How can I remove those patches?

 

Thanks,

         Rich

[robcat2075]

I have not tried this yet but it is a feature. I presume that some judicious reattaching of splines is needed after using it.

 

 

[Darthlister]

Thanks, Rob. Didn't work though.  Is there a way then reattaching a spline to make sure it only patches in a certain direction? (horizontal, but not vertical a la below)

Thanks,

        RIch

 

 

[robcat2075]

why do you need this spline (in red) at all? Isn't it interior?

 

[Darthlister]

It completes the external walls below. If I reattach that spline, is there a way to make it not form that inner patch?

 

[robcat2075]

The red group of splines needs to be one spline loop to prevent a patch from forming there.

Break and delete the four splines that make the red group (leave the CPS in place) and attach a single four-CP loop in their place.

[robcat2075]

Anther solution is to add a spline to any side so that four-CP group is no longer just four CPs.

[fae_alba]

Cura hates internal patches as well as normals facing the wrong way. I've also waged war with five point patches misbehaving when exported to STL. One thing you can try is to repair the mesh in an app like netfab. It can do wonders with STL files from questionable splining ( like mine). I've had to go the hard way and click on the internal spline, break it and delete. One at a time, over and over.