The key is to design it in a way that such precision isn't really necessary. It probably isn't for most of it. Some things are, and for that, it puts the part

The key is to design it in a way that such precision isn't really necessary. It probably isn't for most of it. Some things are, and for that, it puts the part on a precision jig or whatnot, rather than relying on it's own precision. Also, if it works the way they say it does, where it is constantly comparing what it measures against its internal model and adjusting the model (similar to how our own arms and brain works), again, precision (in the geometry of the parts) isn't so necessary.