Hi there, need a little help, I have been using Rhino for years and always found help online when stuck but unfortunately this time a very simple issue but can’t seem to find the answer, I have attached a video to aid understanding but basically trying to join 2 surfaces, a tube surface with overhanging end cap; the 2 surfaces do not join…
Asssumed this may be because lack of edge so split the end cap into 2 surfaces; 2 surfaces will join either pipe/tube to outer end cap or outer end cap to inner end cap or inner end cap to tube/pipe but no way to join the 3.
I have tried boolean, joined the edges and a number of other potential fixes but no luck so far.
You are trying to join 3 surfaces at the same edge. That is what is called a non-manifold edge. In general, that is not allowed in Rhino. Join will only work when only two surfaces share the same edge.
You can use the command NonmanifoldMerge to join the 3 surfaces into a non-manifold construct but be aware that may cause problems for future operations in Rhino.
In real life the cylinder and plate would have thickness and you can easily model that as a solid object without violating the principle that every edge must be shared by only two surfaces. Not_nonmanifold.3dm (625.3 KB)
Thanks very much for the help, I will try this; in this case real life isn’t exactly relevant; I need to model an offshore wind turbine foundation to export to Ansys Aqua for seakeeping / radiation diffraction analysis. The program uses the panel method for this and only accept surfaces not solids, adding the thickness ends up yielding a terrible mesh due to the small thickness that I cannot fix easily in that software; could maybe export mesh directly but that’s a different level of hassle that I can’t be dealing with right now. Thanks again for reply and explaination, going to give it a try now.