Inspired from the single rotor thread and RC plane thread. I have decided to make a multiroter thread. Many people already know that I am in the process of building a quadcopter. So far I have finished the frame with help from my dad and others. Now I am just pondering over the electronics required for it. I have done a lot of research, even though I have not built one yet I am happy to answer any questions. This is an upcoming area of controlled flight so I will walk you through the basics of what is involved. Frame: In terms of aerodynamics, the frames design does not have much effect.The rule of thumb is that you need 4 rods of a strong material that connect to a central point. Such as this Lots and lots of designs, can be made from as little as £15 ( this is what I did) up to £50 depending on what material you want. Also size can be from massive to small. Some people have successfully built 3" frames ( sorry for imperial units, I read rc groups which is a US site) The most important thing is that you need even weight distribution and you really want some sort of carbon that you land on and absorb the impact. Motors: All depends on the size and weight of the frame and electronics. I have not done many calculations and have just gone for emax 2822. Some people want their quadcopters to be very agile so they put a lot of work in deciding which ones to get. In most cases, if you pick up a 800 kv motor with 8" props it should be fine. Speed controller: Turniqy/Hobby wing are good. You need to get the same speed controllers so that you get even feedback across all motors. Also they need to be programmable and at the right ampage for your motor. Electronics: Probably many of you are wondering how the hell these things are controlled. It's all thanks to some electronics wizzadry. Basically there is a flight controller which takes signals from the receiver and outputs signal to the motors to make them the right speed to do what you want. One of the most popular platforms is multiwii which is an arduino controlled system. Usually ran off arduino pro minis. They then have sensors which allow the flight to be stable. Also lots of other nifty tricks such as direction hold, gps hold, altitude hold. Most people usually use these sensors ITG3200 -Gyroscope. BMA180 - Accelerometer. or take them from wii remote controllers and nun-chucks. Multiwii is not the only system, many chinese cheap knock offs are around that mean you can get a system for under £10 ( hobby king board for example). These are generally harder to fly. Besides that there is ardupirates which is very advanced and powerful, also there is open pilot which is cheap but they have supply issues. Multiwiicopter is a good place to get all the electronics, the sensors are very well priced and they sell everything you need excluding the arduino pro. Giant cod is a great place that has UK stock as well. What can you get out of it? With a bit of tweaking, adding a camera and some very expensive electronics you could get something like this http://vimeo.com/21494540 http://vimeo.com/18873955 Be aware that, that kind of stuff is not achievable for under £150, but this kind of stuff is ( well he is using ardupirates, it's more expensive than multiwii but the same sort of things can be achieved with multiwii) http://vimeo.com/20597641 http://vimeo.com/21494540 Hopefully, I will have pictures and videos of my project up in the next few weeks. Cheers and fly safe.