You should always balance your RC model airplane propellers before using them. Running your RC model airplanes with properly balanced propellers will increase motor or engine lifespan, prevent fuel from foaming, and even extend the life of your electronic components. This article will show you how to balance your RC model airplane propellers using simple and inexpensive equipment.
The best way to balance your RC model airplane propellers is to use one of the many prebuilt balancers available. Blade balancers usually come in two varieties:
- finger prop balancers – sufficient for most modelers, you can get good results using a simple blade balancer for 5 to 10 dollars depending on the supplier. Great Hobbies has a balancer which works sufficiently well to balance most model airplane props.
- magnetic prop balancers – produce highly accurate results and are usually more expensive than finger balances.
Use the blade balancer by unscrewing the two metal rings and then placing your propeller in between them. Tighten the metal rings so that the prop doesn’t move and support the entire apparatus with one finger tip on each hand. The prop is balanced if it remains motionless. If it tips forward or backward then you will have to adjust it according to the following procedure:
- Mark the heavy side (which tips downwards) with a felt tip pen.
- Sand one side of the propellers heavy end with medium to fine grit sandpaper. Do not sand the propeller tip – this will cause a dynamic imbalance when the engine is running.
- After removing a very small amount of material from the heavy side of the propeller, test it again using your blade balancer.
- Repeat steps 2 and 3 until the propeller remains motionless while held in the blade balancer.
This procedure will balance your propeller accurately enough to eliminate the most severe vibration during flight. 3D aerobatics, racing, or other demanding flying requires propellers to be balanced more precisely. You can get a higher end magnetic balancer for 20 to 30 dollars. It’s usage is about the same as the finger balancer except that the propeller is held between two magnets.
Check your propeller’s balance using the above method and be sure to follow the manufacturers instructions when putting the propeller in the balancer.