Separating a model into pieces

[micheus]

Hi gnat, welcome.

I cannot suggest much to you since I have no experience printing 3d objects.

From viewpoint of modelling on Wings3D, to break you one block object into parts will require you to identify the edge loops where that should be done, apply the Loop Cut command and make a reconstruction of mesh in that region.

If the object is multiple piece (separated pieces), but acts as one block object then you probably will need to use Separate command in section Body mode.

If you need to make a plain cut of a object session, then you can use Plane Cut.

There are some options depending on the object complexity and the result expected.