You need to balance ALL props, ESPECIALLY WOOD PROPS. The density in each blade on a wood prop is frequently different. The easiest way I have found to balance a wood prop is to paint a bright color (red or yellow) on the tip of the light blade and let dry. When dry recheck the balance and repeat as needed. The bright color serves as a visual warning of where the tip of the spinning blade is.

APC props SAY they do not need balancing. While the majority of them are typically quite close, they are usually off a little.

Whether you fly glow, gas or electric you need to balance your props. The vibration to the airframe from an unbalanced prop can litteraly shake the firewall off the plane.

As for spinners, unless you have to cut the prop openings larger, I don't bother balancing the spinners. Any weight difference will be neglidgable AND it will be close to the crankshaft (not way out like a prop blade ) so it will have little if any effect.

If you have to enlarge the prop openings I balance mine as follows:

1. I have a 2/56 bolt that is 1" long that has a wire soldered to the middle of the bolt head.

2. From the INSIDE of the spinner drill a 3/32" hole in the tip of the spinner.

3. Insert the bolt and secure with a 2/56 washer and nut (It does not have to be tightened ).

4. Pull the bolt until it is against the tip of the spinner and then hang the spinner.

5. Mark the heavy side and carefully sand the INSIDE of the spinner.

6. Repeat as needed until the spinner hangs level.

If you are careful enlarging the prop openings this is usually not needed. If I need to enlarge the prop openings, I mount the spinner and a balanced prop on an engine and run the engine. If I have vibration, THEN I pull the spinner and balance it.