I'm with Rusty on this.
Whether in cartoon or realistically it may be better to lathe a disk or decal a patch and represent the spinning of the props that way versus actually rotating the blades.
One of the reasons this tends to be a better solution is that rotating objects tend to create a false sense of turning due to their symmetry. This is best demonstrated with the example of a character walking past a fence where all the fence planks are exactly the same. The lack of difference in the planks (or helicopter blades) can give the illusion that nothing has moved as the sequence plays.
Having said that there are approaches to this that can work with actual spinning. Those renderings can even be used to get the nice images you'd need to 'cheat' the effect.
I did notice that almost one year ago to this date the answer to your question was answered. I'm not sure you got a chance to read the responses then as you were more interested in the orientation of the blades. Looks like everyone anticipated your question by approximately one year. Check it out and see if this doesn't lead you to the solutions you are looking for. I see about four different approaches here and there, Euler Rotation, Expressions, MUFOOF and imagery.
Regarding the strobing phenomenon:
One of the issues we face when rendering a spin in 3D is that the images will be rendered onto a 2D plane; the screen. Something that looks like its rotating in 3D space may not convey the same movement within that plane. In some cases the rotation may appear to reverse or (something to avoid) not rotate at all. This is fairly easy to address with objects that we can change to create differences and avoid symmetry. In the fence example we might remove a fence plank or tilt one or two in a different direction. This is harder to do with objects such as rotor blades which have an expectation of being the same.
Regarding Euler Rotations.
This was my approach when I created my first rotor animation. Simple math will get it done and its almost as straightfoward as entering the number of rotations; 1, 2, 3 and so on. Just enter the numbers in increments of 360; a full rotation.
360=1 rotation
720=2 rotations
1080=3 rotations
etc.
If you need to rotate in increments of a full rotation (to make sure the spin looks right to the viewer) you can work in thirds/halves etc.:
480= 1 1/3 rotation
540=1 1/2 rotation
etc.
Here's your previous 'Rotor Fix' topic which may already have the solution you need.