On October 21st I bought this at a Toys “R” Us because it was on sale for $25. If you have never flown a quadcopter and have the money to spare, I suggest that you buy one right now (today I’d recommend this one instead, it’s more stable and much better outdoors). At first I could barely get it to hover in place. I crashed it countless times until it stopped working, so I bought another one. I was fascinated by the fact that this tiny thing can take off vertically (even from my hand), hold its position in space, and also move really fast in any direction.
I had an intuition for how quad rotors fly (watch this video for a beginner-friendly explanation) but I wanted to learn more about the technology. As a teenager I’d had a brief period of playing with remote-controlled planes and boats, which back then used combustion engines. Batteries had terrible power/weight ratios so electric motors were rare for flying things. Having precise control over four combustion engines pointing upward would have been difficult, so that’s perhaps why quadcopters didn’t get popular until Lithium polymer batteries (LiPo) became affordable to hobbyists. I started checking out the multiple subreddits dedicated to multicopters, quadcopter specifically, and diy drones. I quickly learned the following things:
- There are two kinds of quadcopters: toys and hobby/pro ones. The first kind are very cheap (typically $20 to $100 ready to fly), come with their own proprietary transmitters, often have a camera. They are generally fragile and mostly harmless because they are very light.
- Non-toy quadcopters can be further split into two categories: ready-to-fly and DIY. The most popular one in the first category is probably the DJI Phantom in its various models starting at around $500. These copters are for people who are mostly interested in aerial cinematography. They are very easy to fly: they come with GPS and know to hold their position in the sky like a cursor on a screen. You don’t get turned around flying them, even if they rotate the sticks continue to move them in directions relative to their original heading by default. They often have a function to come home when they are running low on battery.
- DIY multicopters are significantly more involved. First you have to decide what kind of aircraft you’d like to build. One of the most popular kinds is the 250 (distance in millimeters between diagonal motor shafts). It’s very fast, so typically people use them for FPV racing/freestyle or acrobatics (watch those videos).
- Most people start flying LOS (line-of-sight) as opposed to FPV (first-person-view) because FPV gear is not cheap. Some pilots who are used to the videogame-like dynamics of FPV don’t know how to fly LOS.
Having said all that, an actual drone is something that flies itself. If it has a human pilot, technically it’s not a drone. This week I’m in the process of building a proper drone; I started with a cheap 360mm quadcopter using parts from HobbyKing as described here. I’m replacing the controller by an APM with a GPS/compass module ($70 for both). This hardware supports Mission Planner, which lets you program the aircraft to go do something you want. My next goal is to have it take off, move a short distance, hover for a few seconds, and come back to land where it started.
Also, last week I finished building a 250 “racer” quad with FPV capability that I’ve flown a few times. I’m relatively confident at LOS flying, but FPV seems much harder to me.
This is me flying LOS:
And FPV: