Undercranking a FX1?
 

Hello,

I'm going to be filming some scenes involving helicopters. I want to have one shot with me right under it and have the heli above me with the blades spinning. I know that on film the blades or propellers produce odd visual effects, I want to have a 1 second film so that I can slow it down in Vegas to get the individual blades spinning, if possible.

Anyone have any ideas how this could be done?

Only in post. The FX1 neither undercranks nor overcranks (which is what you want). You could use a very high shutter speed to reduce blur and make the blades more distinct.

But remember that the FX1 moves into CCD smear territory with shutter speeds higher than about 1/500th sec. I'd shoot at 1/50th and give your NLE more info to work with if you plan to slo-mo in post.