When I first got into the multirotor hype, I was not certain what all this quadcopter terms meant nor did I know what parts are good. I went down the most popular road during that time which was a 3S setup about a year and a half ago.
Now that I have gotten more experience in the quadcopter world, I learned what parts things will make you rotor feel like a Ferrari and what makes it feel a slug. Now that I have accumulated gear and tools designed for a 3S setup, it would cost me more money to change from a 3S to a 4S setup.
Today I will be sharing my 4 tricks to make your quadcopter perform like a 4S and get the most out of your 3S, also what I like to call, "Poor Man's 4S".
1. Upgrade Propellers:
The biggest improvement to anyone with a 3S setup is to change your props! If you are currently using Gemfan 5030 Propellers which means, 5 inches in length with 30-degree wing bend, switch to some DAL 5045! With the extra 15 degrees bend, you will instantly feel a drastic improvement to your throttle response. These props are also called "The Unbreakable Props" because it has a much thicker plastic (almost twice the amount of plastic than the Gem fan 5030). I have personally tried these and I have to say if you are a beginner, breaking more than 5 propellers in your flight session, purchase these magical props!
They do not flex as easily but when you do crash then bend slightly, but can easily be bent back in place and look like nothing ever happened. The DAL 5045 is also sold on Banggood.com with free shipping which is only about 40 cents more expensive than buying Gemfans 5030. Now if you are a little more serious and want even more thrust out of your 3S setup, I recommend the Gemfan 5045 Bullnose; also on Banggood. These props have nearly no flex at all, this allows it to slice through the air like a hot knife through butter. The only downside of these is that if you do crash, they easily snap because these aren't as flexible as the DAL 5045 or Gemfan 5030s.
*Please note that the larger the pitch the more amperage it needs to draw from the battery. I suggest 5045 props on a 20a ESC. If you currently have 12a or 10a ESC setup, it will not damage them but may get warm over time and not getting the full thrust. I would not even recommend anyone purchase 12a or 10a ESCs unless you are building an 180mm or below. C rating on your lipo is also important for providing the demanding number of amps from your motors.
2. Reduce Weight:
The second tip is to try to reduce weight as much as possible. If you have banana connectors installed between your motors and speed controllers. I suggest you directly solder the three motor wires directly on to the ESC's. This will remove few grams of weight and make your quad more aerodynamic.
Also, this makes your overall quad rotor appearance look clean without a bunch of wires and banana connectors crammed in the quadcopter. Another tip you may have not of thought of is, if you purchase motors that include these bulky prop nuts in its package, go to your hardware store and purchase some nylon nuts. They weigh less than the free included prop nuts and the inner lining of nylon helps the prop nut from coming off during flight which is a big plus.
3. Finding the Center of Gravity:
You may be asking yourself why does finding the center of gravity important to the amount of power your quadcopter lifts, well that’s an excellent question. Now how does this limit the power? If you go back to high school physics, you remember doing something called equilibrium and torque.
If you forgot all that don’t worry, here is an easy example: is it easier to lift something further away from your body or closer to yourself? That’s correct, the closer the object is the easier to lift, this concept is the same on the quadcopter.
If you have the battery all the way in the back without a counterweight in the front, the rear two motors will be forced to run faster than the two motors in the front. So, therefore, if the quadcopter is unbalanced, when you go full throttle it the front two motors is ru nning at 80% whereas the back motors are at 100%. The front motors cannot be at 100% because it needs to self-level the quadcopter, or it will overshoot the self-level. Usually, you can see your quadcopter leaning towards the heavier side if your I-gain in your PID's is too low.
How do you balance your quadcopter? The easiest way is to balance the center of the quadcopter on a block no thicker than your thumb. Overserve which direction it begins to fall. Try NOT to add counterweight but instead, remove weight on the other side that's heavy, if you absolutely cannot remove it, then place it closer to the middle i.e. having the battery way in the back, place it in the center. Now if you must have the battery in the back, try adding a GoPro or Mobius Action Cam in the front.
That is why many quadcopters have a camera onboard to offset the battery weight.
4. Tune the Multi-Rotor:
Ah, tuning the quadcopter, one of a drone newbie worst nightmare, don’t worry I went through the same stage. It is very important to make sure your quadcopter is tuned, not only will this save you the embarrassment of having to fly a quadcopter sounding like its having a seizure, or be flipped over by the wind; you will also relieve a lot of stress from the motors. You all have heard of oscillating quadcopter; if you didn't know it is drawing more power to oscillate.
When something is turned down and then needs to turn back up, the acceleration draws more power from the battery as well as limiting the max throttle you can push it. The oscillation needs leeway to go back and forth so it limits the throttle to about 80-90% depending how bad the oscillation is. I will not talk about PID settings and tuning in this article because it is quite a long topic. Although, the quickest way to fix this is to turn down P-gain on roll and pitch. Lastly, do not confuse yourself between a quadcopter with a high P-gain and quadcopter with imbalanced motors or propellers, check your props and motors!
I hope this article has helped you to maximize your 3S setup and get the most power out of it.
If you like this article, please share with others and if there is something you would like me to talk about please, feel free to let me know.