Hi Greg - could you please attach a .3dm model file with your hexagons? That would help to see exactly what is going on.

From your description though, it sounds like you may have a set of individual line segments that are all touching each other? That would make for a kind of branching structure where each line was not just touching one other line. If so then that is the problem - MoI's extrude command does not know how to handle open curves that touch each other in a branching way like that, for open curves it is only expecting to have segments that touch only one other segment to form closed loops.

Instead, you'll want to have either each hexgon being a closed curve itself, or you would want to throw out all the "internal" segments and only have just one outline around the outside if you want it to extrude as all one block instead of as many different smaller solids.

But if you can post the file I can see if that was the problem or if it was something else, and maybe try to show you a screen capture to better illustrate what I am talking about above.

Also one quick note on making a hexagonal pattern - the Transform / Array / Dir command can be useful for that - for example here I apply it twice in different directions to get a full pattern:



- Michael