Hi danekshea,

> Is this necessary though or does MOI automatically make it a coherent structure when exporting?

MoI will not attempt to alter the overall structure of your objects when doing an export.


re:
> but can I just keep them all as separate parts?

Generally no not for STL export to a single STL file unless there was some space between them. Most of the time for STL format the receiving programs that will process the STL up into slices to send to the printer does not expect for there to be multiple triangles sticking through each other or grazing right on top of one another, it expects for triangles to only touch one another at their boundary edges only.

But like Mike mentions above if the pieces are going to be printed separately you could export each of the pieces to its own STL file rather than doing it all in one STL file. You do that by selecting the individual object you want to write and then use File > Export rather than File > "Save As". File > Export will only write the selected objects to the file rather than writing everything.

The thing that won't work properly is to have multiple different objects that are touching each other all exported to a single STL file, that will make it hard for the receiving program to figure things out.


re:
> For some reason if I union this design then 2 of the legs disappear(not sure why)

Having tubes that come together like that tends to be a difficult case for the surface/surface intersection mechanism to resolve. Are you using version 2 or version 3 though? There have been some tune ups to that particular area in v3.

If you can post your 3DM model file or e-mail it to me at moi@moi3d.com, I can take a look at it and try to give you some suggestions on how to get this unioned together. Sometimes it can work better for many tubes of the same radius to come together at a hub rather than colliding directly into one another.

- Michael