Propellers. We all know what they are and what they do. We also know how important they are to keep your drone in the air. What you may not know, however, is the importance of balancing your propellers, primarily on larger drones. Good thing we'll be covering that today!
Why You Should Balance Your Props
Before we talk about how to balance your propellers, let's cover why it is so important. Let's say you're flying your drone. It's a calm day, with clear skies, no wind, and you haven't had too much coffee. Yet, when you are flying at a consistent altitude and bearing, you notice a little wobble and it's not quite as smooth as it should be.
This can easily be explained by the propellers being out of balance, much like a set of tires.
You may not notice it if it's high enough or if you don't have a camera on it.
But let's say you're doing an aerial shot. You are going over your scene with ease, and then when you upload your footage from the drone to your computer, you notice a slight wobble. Slight wobbles can ruin shots.
Now, most of the time you can fix that footage in post, but speaking from experience, sometimes you just can't, and it can be a pain. Instead, it's best to get rid of that issue entirely by keeping those things balanced. You'll save yourself tons of headache down the road.
Not only is it an issue with your quality of flight, this consistent wobble can start to cause extra wear on the motors and bearings in your drone. This leads to having to possibly replace parts much sooner, or in extreme circumstances, that drone falling out of the sky. Yikes!
How To Balance Your Propellers
Now that you know why it is so important to balance your props, let's cover how to do it correctly. First, you need a prop balancer. Though you can find these all over the place online, you need to be sure you are getting a quality balancer, otherwise you are just wasting your time (and money!).
Unfortunately, it does not come with a shaft that fits DJI blades, so you'll need this shaft.
Once you have your balancer, you might want to check to see if the balancer is…in balance. To do this, just put it on a level surface and confirm that the rod on top is completely level. You can use a symmetrical object to put under the balancer, and confirm it sits level on both sides.
Next, check to see if the propeller is unbalanced by placing it on the rod in the center, and see if either side tips one way or the other. Once you determine which side is heavier than the other, it's time to do some balancing.
There are really two schools of thought on this: You could either take away weight from the heavier side, or add weight to the lighter side.
You could remove weight by getting some sand paper to sand it down a bit, but this is pretty risky and you could end up over sanding it or causing more damage to the blade than you intend. This could lead to even worse results for flying quality.
Adding Lighter Blades
The more recommended way would be to add a little weight to the lighter blade. There are a few ways you can go about this. You could take some scotch tape or something similar, and put a small piece on and see how it weighs out.
You could also put some sort of small sticker or something else, as long as isn't too think and starts to affect the overall quality of the blade itself. A small piece of tape may not seem like much, but sure can make all the difference in the air.
The best spot to place the tape on the bottom of the outer edge of the propeller. By placing it on the outer end, you will need to use less tape to bring it into balance.
Once you have it adjusted, whether it's removing or adding weight, go ahead and put it back on that balancer. It should now balance perfectly without tilting. Make sure that it's facing the same way up as when you tested it last time, to assure that there aren't any issues.
Next, you should check out the hub. Go ahead and flip the propeller so that the side that was facing down is now facing up. If it's unbalanced, it'll tilt. You should then try adding a little weight to that side (maybe a pinch of glue?) and that should balance it out. You can also check the hub by tilting the propeller vertically to see if it tilts one way or another.
Once you've run your tests and adjusted accordingly, you now have an amazingly balanced propeller. Plop that thing back on your drone, secure it, and have some fun!
Here is an excellent video demonstrating how to properly balance your propeller: