Unable to join polysurface

Hi All

I’m having trouble joining 2 surfaces together. I extruded a curve upwards from a surface and now when I go to join the extruded surface and the previous surface I am unable to do so. I also used the show edges command and it shows some naked edges, but I can’t seem to find them when I look for them.
Hot-Cup.3dm (647.1 KB)

Hi there,

I am not clear exactly which part of the cup you are talking about, but if you mean the four circular indentations in the bottom of the cup (which won’t join as things stand), then the problem is probably that you still have four circles of the surface in place and joined to the rest where the openings should be. You can either remove the circles or shift them down (up?) a bit and use them to form the bottoms of the holes. After doing that the rings will join to the rest of the cup. (Use Extract Surface to select the four circles without having to explode the whole cup.)

Hope that helps