Best of luck rpetersson
CNC machines were way out of our reach when I was having ideas like that. Rather than re-invent the wheel why don't you try doing something that has never done before (everything's been done before) with building a jet engine.
Here are some ideas, and I'm not promissing they are any good.
1) Forward swept axial flow compressor blades. Look cool too.
2) Outer rim air bearing. To prevent tip path losses the blade tip is connected solidly or cast to an outer rim which has tiny holes in it to let air pass through from centripital forces and form a boundary layer of air to act as a lubricant.
A friend of mine (ex aircraft engine maintenance engineer) who is now in the auto turbocharger reconditioning business told me a story about a buch of visiting scientists who in a laboratory were 'growing' turbine blades one crystal layer at a time and were looking for a machine that could balance their spining fan at 200,000 rpm. Incredible stuff.
Have fun.