RC helicopter blade balancing is considered by some to be an art all by itself and some people never really master it. Sure, there RC helicopter rotor balancing tools that you buy, but why spend that money if you do not need to? Or what if you need to balance your rotor blades and do not have that tool nearby? Is it possible to balance your rotor blades without a balancing tool?
Yes, it is!
This article will lay out a free and very effective way for you to be able to dynamically and statically balance your rotor blades. All you'll need to do is spend a little time and energy to do it right.
Some people have wondered why they're even balancing the rotor blades to begin with and the answer is very simple: to get rid of unwanted vibrations in the RC helicopter. It's kind of like driving a car with one wheel out of balance – it just throws the whole ride off. With RC helicopters, instead of throwing the flight off, it can seriously affect its flight performance and the vibrations that ensue can even tear your RC helicopter apart!
The core idea with rotor balancing is to get rid of as much of the unwanted vibration as possible. You may not be able to get rid of them all, so do not be upset if there is a little vibration leftover.
The method that we're going to use is effective and does not take long at all, but it's important that you do it with caution and accuracy. When it's all done, you'll have blades that are static and dynamically balanced.
This is what you'll need – your main rotor blades, a round shaft (market, main shaft etc.) of some kind, a sharp pencil, electrical or balancing tape, some thread, and a nut and bolt.
How To Balance Your Blades Dynamically
1. First, we want to determine that out center of gravity is the same for each blade. Here's how we do it:
2. Place your round shaft on a flat surface.
3. Place one rotor blade at the top edge of the round shaft, balancing it with your fingers Slide the blade back and forth until you find its balancing spot (also know as the center of gravity).
4. Now mark that spot with a pencil and do not move the blade as you mark it.
5. Do this with the second blade as well.
6. Now, match up the blades by laying them on top of each other.
7. Move the top blade enough to see where the balancing point is for it and compare the two points.
8. If they're more than 1mm apart, you need to change the balancing point on the blade that has it's center of gravity closest to the blade tip, by transferring the balancing point closer to the bolt hole. You can do this by adding small strips of tape near the bolt hole until the center of gravity points match on both blades
9. Repeat this until you have applied enough tape to make the necessary correction to match the center of gravity (balancing point) of both blades and you're done!
How To Balance Your Blades Static
This type of balance matches the weight of each blade to the other and here's how we do it:
1. Take a nut and bolt and attach the blades together and set them symmetrically apart like they would be in flight.
2. Hang the rotor blades from your thread. You can do this with a wing nut or simply put the thread between the top blade and the nut before you tighten them together. Just make sure that the thread is lined up with the center of the blades or you've just wasted your time. You can also center the ends of the bold between two objects of equal height (like a 2 by 4) to balance them.
3. Pick up the blades by the thread and let them hang naturally. Look at them at eye-level to see if they're level or if one rotor blade is lower than the other. If they're level, then job well done! If they're not level, then we need to fix it by adding small strips of tape to the blade that is higher (it means it's lighter).
The key is to add the strips near the balancing point, or center of gravity, so that you do not undo all the work you've already done. Just add the tape until they're both level and when they're level, you'll know that they're balanced! You're now an official RC helicopter blade balancing guru! Well done!