Prior to flight, take a few precautions to ensure that your propeller will perform as needed. Inspect your propeller for visible nicks or damage. Particularly with a constant speed propeller, grab your blades and insure there is no play in any direction. Listen and feel for unusual noises and vibration. Look for loose bolts or a tip that might have separated during the start and taxi sequences. All props vibrate to some extent during operation. However, propeller roughness may be caused by 1) bent blades 2) blades out of track due to improper mounting of the propeller on the engine shaft, 3) imbalance, 4) a propeller loosely mounted on engine shaft, 5) angles between blades are out of tolerance 6) spinner imbalance due to improper mounting or dirt, snow or ice inside the shell.