For CAD/CAM type stuff, Rhino seems to be the main one I've seen around these parts. It appears to do most of the NURBS and draftsman/engie things, short of getting really spendy with Autocad or Solidworks. Visit the forum/gallery and invetigate what people are doing. There's a lot of neat cars/airplanes/etc. to be seen.

If it was just general poly-pushing, I would have said Wings because it's free, has little overhead, and you can quickly learn how Catmull-Clark subdiv works (which is what every polygon app uses to some degree.) A lot of poly programs also export to file formats like .stl, which is useful for rapid-prototyping. Still the problem that arises is to what degree you can get any precision may vary. I suppose that's why the NURBS route is preferred for this type of application. (But if you're just doing figurines or something of that sort with no real mechanical fits, then you could probably get by with .stl exported from a poly-based application.)

Also since you're already on Maya, I'm surprised you haven't checked out some of the CAD related plugins and things like T-Splines. Seems like those options may be easier than learning a whole new software. (But then again, ask around about costs and workflow considerations.)

---

Barbequed Pixels?

Your friendly neighborhood Wings3D nut.
Also feel free to browse my freebies at ShareCG.
There might be something worth downloading.