We bumped into the AC3D 3D modeling tool and we like the price: only USD$89. But what do you get with AC3D? This multiplatform tool (multiplatform meaning Windows, Mac and Linux) includes the ability to work with almost 40 different 3D formats including most of the 3D printing-related ones: 3DS, Collada, KML (Google Earth), OBJ, MESH, and of course STL. You can import and export many of them.
It's a pretty capable product, as you can see in the 3D rendering above (click for larger image). Along with the usual 3D modeling capabilities like extrusion, rotation, mirroring, stretching, etc., AC3D has several advanced features:
- Warp and Bridge non-similar objects with their convex hull function
- Reduce polygon count but retain shape
- Paths and operations on them, like extrusion
- Drag and Drop object manipulation
- Align objects to each other, and grid snapping
- Drilling holes
- SpaceNavigator support
- Text operations
- Subdivision surfaces to easily create organic shapes
There's also a community support forum, tutorial videos and more. At this very low cost, it seems like a winner.