How to fix open polygon mesh error in my Triply Period Surface element

Hi all,

I have created two different elements of a triply periodic minimal surface on Rhino and used the same Gh script for both…however I’m encountering problems in both of them as they keep on coming up as open polygon meshes…I’ve tried RepairMesh but it doesn’t fix the problem. I’ve tried ignoring this error before and carried on offsetting the meshes, however the final geometry just doesn’t look right… (the ultimate goal is to produce an STL and gcode files for 3d printing)…

Perhaps there’s something wrong in the way I created the flat surfaces?? I describe my workflow as below.

I created symmetrical sets of curves (squares and rectangles)inside a box in Rhino, after this I mirror them to have symmetrical elements. I then set these curves on to my GH definition to generate a mesh…and bake!

Attached are screenshots and the actual Rhino and GH files.

Any help would be very much appreciated as this persistent issue has started to frustrate me…

triply (15.4 KB)
triply help.3dm (2.3 MB)