This may be a little late for you but AutoCAD FUSION is available for free for hobbyists. It is CAD/CAM and is fairly simple to learn the basics. It is made for machinist design and CNC. I have not explored if it outputs 3 view drawings. Give it a try.
While Inventor, Solidworks, Pro E, etc. are powerful and are meant for 3D design, don't count AutoCAD out. It isn't parametric like the big boys, but it still works great for 3D. I've been using AutoCAD to design piping systems and structural steel for years now. The lack of some features is somewhat offset by the ease of learning AutoCAD 3D.
The main commands for creating 3D solids are by creating and combining primitives (Cubes, Cylinders, etc.) and through using commands Extrude, Revolve, Sweep, Loft, Union, Subtract, etc. with closed Polyline perimeters. Change the alignment of the plane you're drawing on by rotating the User Coordinate System (UCS). Remember that extrusions only project out in the Z axis. Use Views (Top, Front Right, Back, etc.) to swivel both your view and the X,Y,Z orientation. Press Shift&Middle Mouse button to rotate your view perspective without altering the current X,Y,Z orientation. Use commands like Union, Subtract, and Intersect to join or carve-out solids. Regular commands like Mirror, and Array can be used to make patterns of features like holes or stiffening ribs. Check out Youtube videos, and the AutoCAD help files for examples of how the commands can be used. I'll be happy to share what I know; just give a shout.