How about we try some numbers?
- You want one microfarad of capacitance between your moving plate and a fixed plate.
- You'll need some space between the fixed and the moving plate - if they are too close together they'll drag and you don't want that.
- Capacitance of a parallel plate capacitor is given by \$C = \epsilon_0\frac{A}{d} \$ where \$C \$ is in farads, A is in the area of the plates square meters, \$d\$ is the separation distance between the plates in meters, and \$\epsilon_0\$ is \$8.8541878128(13)×10^{−12}\$.
As you can see, it takes a very large area and a very small separation to get large capacitances.
Assuming a separation of 0.5 mm, and a capacitance of 1 microfarad, you'll need an area of an area of about 60 square meters. Spinning. At 60 rotations per second - that's 3600 rotations per minute. That's a thing nearly eight meters across rotating at a very high rate - with a clearance of 0.5 mm between the surfaces.
Do you see a problem here?
Your idea is impractical, even if by some chance you got the physics and mechanics correct.
I see on re-reading your question that the moving plates have a capacitance of 5 microfarads.
That makes the area much larger.
You'll need around 300 square meters.
That's a thing 17 meters across, spinning at 3600 RPM, at 0.5 millimeters from the fixed parts.