You need a motor, a way to mount the motor, a method to mount flies to the motor (most use a styrofoam disc), and power for the thing...How you do all this is up to you, and not all that critical as long as it works for you....
I made mine with an old rotisserie motor..Found it cheap at the thrift store....I used an old line spool and some aligator clips stuck to it for holding the flies...works great....or...
You can get low RPM motors at
www.AllElectronics.com
They have lots of different ones for differing applications, and they are cheap.
Buddy
It Just Doesn't Matter....