Quadcopter Buying Guide

So you’ve decided to buy a quadcopter, now what?

DJI_T600_Inspire

The first plan would be to google something like “best quadcopter”. And I’m sure you will find thousands of websites that say they have the 5 or 10 best drones available for you to choose. If you haven’t tried this, you might find it instructive, as it will teach you how confusing all the options are.

What most websites don’t get is that each person wants a quadcopter for a different reason. Some people just want a small and safe Christmas gift for their 8-year-old daughter, while others might want to buy a quadcopter to inspect crops in their farms. However, they are all treated the same way in websites: “Get the best quadcopter here!”

My first goal is to show you how wrong that approach is.

As you might have seen in your previous searches, quadcopter prices vary from under $10 to $1000+. But how is that possible if they all sort of fly the same way, they all have 4 motors, and all their owners say they own a drone?

Well, as with many other products in life, the functionalities and features play a great part in this price difference. Also do the quality of the materials, the motors, batteries and even technical support. However, what other websites try to do is just push 5 or 10 (hopefully) good products that cost more than you would want to pay, and that have different features than what you really need. Instead of focusing on instructing and satisfying visitors, they hope to attract people to their “Best Drones” posts and just make a sale, which is clearly the wrong thing to do.

What I intend to do here is really show you, the awesome reader, what are the features and functionalities available, and help you decide what you need and what you don’t. This way, you can save some money, buy a quadcopter with only the features you need, and fly it around happily.

This guide will be separated in a few parts, each part will have a few items, and each item will have its description and examples. Feel free to check only those that interest you, or that you are curious about. And let me know if you’d like more info about any item in particular.

1. Number of rotors:

DJI_S1000_Octocopter

When we talk about quadcopters, they all have 4 rotors, but it’s not uncommon to find hexacopters (with 6 rotors) or octocopters (with 8 rotors). (And some of those certainly look more badass). The point is that it’s possible to have a drone with any number of rotors. (And if you consider a helicopter, the minimum is 2).

These extra rotors usually increase the load capacity of the drone (i.e. it can carry more weight, a heavier camera), the stability (i.e. it becomes easier to fly, less shaky), and the speed (i.e. it goes faster). However, when you have more motors, the battery life might suffer (i.e. the flight time can be reduced), and you also need a bigger and heavier frame to support them.

In sum, if you have a specific application that needs the extra load capacity and stability (e.g. filming), you might want to check drones with more than 4 motors. However, if you just want to have some fun, sticking to the good ol’ quadcopter is a good idea and can save you some bucks.

There is one exception, which is in the small-drone category, in which both 4- and 6-rotor drones seem to cost the same. But please bear in mind that having more rotors means more parts to break when it crashes.

2. Frame quality:

Makerfire_H250_3K_Frame

The frame is the central part of the drone, which holds everything else together. And there are two things to consider when looking for one: aesthetics and performance.

First, nobody wants an ugly frame, so beware that there are ugly frames. But this part is easy, you can just look at the pictures and decide if it fits your fashion requirements.

The second part is trickier. Basically, the more rigid the frame, the easier it will be to control the drone. By “rigid”, I mean how hard it is to twist the frame.  Cheap frames tend to be made out of plastic and have a bad geometry, so they might even look OK from the outside, but many times they are not rigid enough, so it becomes harder to control the drone (e.g. make it stand still and maneuver). This is a detail you need to be aware of, but usually it will not be possible to decide whether the frame is good or not only from the pictures.

There is a compromise between the rigidity of the frame, its weight, and cost. For example, it’s possible to have a very rigid frame that is very light, but it will be expensive! On the other hand, it is possible to have a very cheap frame that is rigid, but it will be heavy (and reduce the flight time and load capacity). Good frames tend to have reasonable performance in these three dimensions.

So, if you want a drone for filming, it needs to be reasonably stable, otherwise your video will be shaky even with the best gimbals (more on gimbals later!). But if you just want to have some fun, maybe price is king.

If you are interested in checking what I mean by rigidity of the frame, you can check this video.

3. Gimbal:

The gimbal is the structure in the quadcopter that holds the camera (if there is one). It is normally attached in the lower part of the frame and it can be fixed or movable. This is an important feature because it will say which type of camera you can use, how stable the filming will be and how much the drone will cost you. If you don’t want to do any filming nor use any camera, please skip this item.

There are two types of gimbals. When it is fixed, the camera will always be pointing in the same direction, so you have to maneuver the drone around to film what you want. In addition, the camera vibrates and shakes as much as the quadcopter. However, this is the cheapest type. You can use it if you don’t need professional, stabilized video, or maybe if you just want to see where your drone is going in First Person View (FPV).

When using a movable gimbal, it’s possible to control where the camera is pointing at with the remote control. For example, you can move the camera up and down and choose to film the ground or the horizon, without moving the drone. Also, for some more advanced gimbals, the camera can be stabilized, achieving a better filming quality.

If you decide to go for the movable gimbal, please note there are 2-axis and 3-axis gimbals available. The number of axis means in how many ways you can rotate the camera. In other words, in both 2- and 3-axis gimbals, it’s usually possible to rotate the camera 360 degrees (e.g. looking the horizon. This is called pan), and also look up and down (e.g. from the ground to the sky. This is called tilt). The 3rd axis refers to rotating the camera sideways, like how a dog looks at you when you try to explain how cool drones are, and this is called roll.

You might have noticed I didn’t say anything about 1-axis gimbals, that’s because they are hard to find, and most I’ve seen either already come with the drone or are homemade. In case you want to choose between 2- or 3-axis, it’s good to know that good 3-axis gimbals usually cost $100+ in retail, but 2-axis stay between $50-$100. So bear this in mind even if you choose a quadcopter that already comes with a gimbal.

4. Flight time:

Teenitor_Upgrade_600mAh_3.7V

When you are comparing quadcopters to buy, it’s important to observe for how long they can fly on a single battery charge. The flight time is an estimate of the maximum amount of time they can stay in the air.

For example, if it says 10 minutes of flight time, this means you can play with it to a limit of 10 minutes, which is the best case scenario. In other words, if you fly it for 10 minutes, the battery will be totally discharged. However, you must consider that you should never use it for that long, because if you do, the battery will discharge totally and your drone will fall mid-air (and probably break =/). So you should always have a security margin.

Having a security margin means you will bring the quadcopter back and land it safely despite you could still fly it for maybe 2-3 minutes. You can choose the size of your security margin, but I would recommend 2-3 minutes if you are flying outdoors and high in the sky. If you are close to the ground or indoors, then this security margin is not that important, since falling shouldn’t really break anything (but beware of the risk!).

So, how do you decide what’s the ideal flight time for you? If you are an enthusiast or use the drone only as a toy, a smaller flight time might be more interesting, especially if you won’t use a camera nor make videos. In the worst case, you can buy additional batteries, so you can have a small flight time, but use the quadcopter multiple times.

In many cases, buying additional batteries can be cheaper than buying a quadcopter with a longer flight time. For example, a quadcopter with 10 minutes of flight time with one additional battery can cost you less than buying another with 20 minutes of flight time and a single battery. In this situation, you would fly for 7-8 min, bring the drone back, change the battery, and then fly it for another 7-8 min, instead of just flying it once for 18 min.

Longer flight times are recommended if you have a specific application in mind like filming or racing. And if you do, you probably will also have additional batteries. In this case, keep in mind the longest stock flight time you will find is somewhere around 30 minutes, but it’s always possible to make mods or use larger batteries and increase it.

 


What do you think about number of rotors, frame quality, gimbals, and flight time? Let us know in the comments!

One thought on “Quadcopter Buying Guide

  1. Mini Drone says:

    Great little buying guide!

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