Published on August 23rd, 2013 | by Quadcopter News0
3 Steps to Balancing Your RC Props
You should know that when it comes to balancing your rc props, this is a simple thing to do, so you must not worry. Although it might take some time, it will all be worth it, as an rc propeller that is perfectly balanced will prevent your plane from vibrating so much. In turn, this will be highly beneficial for it because severe vibrations can unfortunately disturb both its electronic parts and its airframe, which is not desirable at all. All in all, if you take the time to balance its props, it will all be worthwhile.
Before actually starting the process of balancing your rc props, it is highly recommended to purchase a qualitative balancing tool. Although you could also build such a tool yourself, it is better to actually buy one, as it only costs a few dollars. One consisting of a prop-clamping device and a spindle is more than enough for the job you need to do.
Balancing Your RC Props: Step 1
First of all, you have to secure the props you need to balance in your balancing tool. The tool you bought should have its own instructions, so you should take a look over them as well. Nonetheless, make sure that your rc props will hang freely once on the tool. However, before doing this make sure that you are in a room with no air movement, as even breathing heavily near your props could give you a wrong impression of how balanced they actually are. After placing your props on the balancing tool, let it rest naturally. You will soon be able to observe that if one of the blades is heavier than the other, it will hang lower.
Balancing Your RC Props: Step 2
After you determine the weight difference between the props, you can choose solving the problem in two different ways.
- The first thing you can do is to try and balance the prop’s hub. If your props have at least 8” or more, you should know that this is the best way to go. In order to obtain this balance you have to carefully drill some very small holes on your lighter side hub’s back. These holes should then be filled with fishing shot, small lead pieces or liquid ballast. Each hole must be drilled and then filled one at a time. After each filled hole, you should place the props on your balancing tool in order to see if anything is changing.
If you have large diameter rc props, it is probable that they are already drilled from place to place. If this is the case, you should not drill any other holes, but just use the existing ones. As far as filling the holes is concerned, you should not use ballast for all of them. As soon as you see that your props are almost balanced, start using foam or balsa for the other holes. Since these materials are not heavy, they will be perfect for the final step of balancing the rc props. When you manage to balance them, use some CA glue or some foam in order to seal the ballast you used. It is not recommended to use any other kind of glue, such as epoxy for instance, as this will only add more weight to your props and put them out of balance once again.
- In case you have smaller rc props, you should use this second method of balancing them. In order to do this you need to start by balancing the blades of your hub. Either you decide to add some weight to your lighter blade or to remove a little bit of weight off your heavier one, both will do.
If you decide to add weight, you can do it by using some tape. This can be easily stuck to your lighter blade’s back. Although this is a very quick fix, you should know that you may have to repeat the process over time, as the tape will most likely fall off after a while. Another quick method of adding weight to the lighter one of your rc props is to paint it on the back. You might have to add multiple coats on it, reason for which it is highly recommended to recheck its balance on the balancing tool after each added layer. As far as the paint that you have to use goes, make sure that this is suitable for the material from which your props are made of. In case you want to give your rc props a safety advantage, you could also paint their tips in yellow or in white. However, you will still have to add more paint to your lighter prop, so that it will balance the other one.
On the other hand, if you decide to remove weight from the heavier prop, you should know that you can easily do this by removing material from it. This can be done by sanding away your blade’s back. However, the sanding must be done close to its hub. In addition, this procedure must also be kept to the blade’s inner 1/3 length. Bear in mind that this procedure is effective only in those cases where the blade’s imbalance is a minimal one. In case your rc props are quite out of balance, it is more recommended to add weight to the lighter prop rather than to remove weight from the heavier blade.
Balancing Your RC Props: Step 3
The third thing you need to do in balancing your rc props is to recheck their balance every time you do something that might alter it. This is how you will manage to find out just how much or how little weight you will need to remove or to add in order to restore their balance. As soon as you succeed in balancing your props, you will see that once you place them on your balancing tool, they will not rotate anymore, regardless of their position. Nevertheless, bear in mind that if the propeller stops for a little while and then begins rotating again, it means that it is still not properly balanced and that you must continue trying.
- Before starting the process of balancing your rc props, make sure that you remember to measure the distance between the hole’s inside and the blades’ tips. If everything is right, the distance between the two should be equal on both sides. However, if you notice any discrepancy, try and sand back a little bit the blade which is longer until this reaches the other’s length. While doing this, make sure to keep its tip shape as if you mess it up you will not be able to balance the two props anymore.
- In addition, before actually setting the rc props on your balancing tool, remember to check if your prop is rotating in an even manner on its own prop adapter or motor shaft. In case you notice a vibration or any other kind of trembling it means that your propeller’s hole is not 100% perpendicular to its hub. In order to correct this, you have to carefully ream the hole. Before actually doing this though, try another prop in order to see if the same thing happens.
- Another thing that you might want to take into consideration before actually balancing your rc props is to try and concentrate your entire attention to what you are doing. If you want to be able to observe any little plane vibration, make sure you recheck your propeller’s balance from time to time. Unfortunately, even if you might like it or not, your plane’s props will make ground contact and this will most likely result in an imbalance. Usually, these imbalances are a result of the fact that very tiny pieces of your rc props get lost with every ground contact that your plane has. This is why it is highly recommended to only fly your plane in open spaces and not indoors where there is a greater possibility of hitting something. In the unfortunate case that your plane’s propellers are very badly damaged though, you should also know that it is not indicated to try and repair them, since it is very unlikely that you will manage to get them balanced again. The only thing you can do in this case is to replace them with new ones.
All in all, the importance of balancing your rc props lays in the fact that as long as these are balanced, your plane will be flying properly as well. A plane that has balanced props will most likely have a longer lifespan, as the vibrations in it will not cause its other parts to damage. Unfortunately, if a plane’s props are not balanced, the entire device will vibrate more. In time, this will cause its inside parts to malfunction. Therefore, in case you have not thought about it until now, you should consider balancing your plane’s rc propellers as this will only increase its lifespan and bring you more joy when it comes to using it.