Are there any graphics programs that work like AutoCad or Inventor where you can draw objects and give them precise dimensions? Even better, something parametric like Inventor. I don’t like lining stuff up by eye or using flaky snap grids. I’m hoping for something really extensive, and straight forward as if one was drawing simple parts (I plan on making icon vectors). Is there anything like this?
Presumably you mean “free” since you have mentioned two extensive packages that do what you want.
FreeCAD is an open source parametric 3D modeler.