I can't get a successful gcode for this object  

Re: I can't get a successful gcode for this object

Lots of errors in this model.

From Rhino:
This is a bad mesh.

Here is what is wrong with this mesh:
Mesh has 179 degenerate faces.
Mesh has 88583 non manifold edges.
Mesh has 4306 duplicate faces.
Skipping face direction check because of positive non manifold edge count.

Important things to consider with this mesh:
Mesh has 221215 pairs of faces that intersect each other. Although this does not
necessarily mean that the mesh is bad, it can cause problems if you're doing mesh boolean operations with it.

I uploaded the model to NetFabb and while it was processing it I looked at your model more closely in Rhino, I can see small holes that pass all the way through. Look at the dotted line around the center of your model:

Here is a zoomed in view from the bottom:

And a zoomed in view from the top:

NetFabb worked on this for several minutes then reported:
FAILED: failed to load mesh (#103)

Even if you could repair this model, you should try to fix it (or re-start it from scratch) to eliminate all the holes.

Re: I can't get a successful gcode for this object

Wow, thanks for the feedback! I am going to start again and try to find a better way to make the "teeth" so it doesn't have holes like this.

I've never heard of NetFabb before... is that a good thing to use for any model?

Re: I can't get a successful gcode for this object

I've never heard of NetFabb before... is that a good thing to use for any model?

NetFabb is an online model repair site https://service.netfabb.com

If you have an STL file with errors in it, you can upload it to NetFabb and it will attempt to repair the errors. If it's successful, you can download the resulting file.

You'll find that many of the STL files you find on the internet have errors in them.