I have posted about building my own frame for under $10 and it is possible to build a frame very cheaply that will fly. However, it is hard to be precise without a CNC or laser cutter. Unless, you like to tinker, I would recommend buying a kit frame.
One of the best is the VC-450 from Hoverthings. It costs $75. It is easy to put together and is precisely engineered. For beginning or expert pilots, it is hard to beat the VC-450. (Update 06/09/12 – The VC-450 has recently been discontinued. It was replaced by an upgraded frame called the HT-450 which is a bit more expensive.)
Other good frames are available that cost even less. Some members at RCGroups and other forums will cut frames using their CNC or laser cutters for $50 or less. Usually these frames consist of center plates and motor mounts made of G10 and you provide your own wood or aluminum arms purchased locally.
There are many high end frames that I have not tried, and they may be great, but I don’t think it is necessary to spend over $100 to get a good frame.
4 Motors $65
There are so many choices for motors out there that it can be overwhelming. My best advice is to find motors that match up well with the frame and payload of your quadcopter. If the size and kv are wrong, they may be unusable.
Quality motors can be had in the $15-20 range and there are many choices. I have some KDA motors and some Turnigy SK3 motors that are in the $15-20 range that I am very happy with.
I would avoid motors under $10 and the ones over $20 are just too pricey for me.
Turnigy Plush ESC
4 ESCs $45
From what I have seen, the Turnigy Plush ESCs are one of the most popular ESCs around. They cost a little over $10 and are often sold out and on backorder from HobbyKing. Lots of sellers on Ebay get much higher prices for them because of this. I was lucky enough to get a set from HobbyKing and they work great.
When I have needed more ESCs, I have been able to find generic versions, under other brand names that are very similar to the Turnigy Plush ESCs for about the same price. I just look to see what kind of programming card the generics use. If it looks exactly like the Plush programming card, I assume it is a clone.
There are much higher priced ESCs, but from what I understand, these are sometimes rebranded versions of the same thing, so I suggest something like the Turnigy Plush or a low cost clone.
4 Props $5
I started out using APC propellers. For 8 inch props they are about $16 a set. They are great props, but I was crashing a lot when I started out, so I switched to Gemfans that can be had for less than $5 a set. Now, I am not crashing much, but I still like the Gemfans. I found the props I currently use for $4.00 per set at DIYQuadCopters.com. They are Gemfans and Dan who runs the site is very helpful and ships from the USA. A set of four includes 2 CW (labeled R on the prop) and 2 CCW props.
I prefer using prop adapters instead of prop savers. I had an old prop saver O-ring snap in mid air and down she came. However, if you make sure the O-rings are good, prop savers can save your motor shaft from getting bent in a crash.
Flight Controller $30
Choosing a flight control board depends on a pilots skills and what type of flying they want to do. This is an area where I don’t mind paying up for the features I want.
Easy Flier – I am an inexperienced pilot and need a board that does good self leveling. For line of site flying, I use the OpenPilot CopterControl board that cost $90. It has rock solid firmware and is easy to configure. Unfortunately, they have stopped making it. The new OpenPilot CC3D board is expected to be out soon and should be available in bigger quantities. I don’t know what the price will be.
Update – 7/19/12 The Hobbyking KK2.0 Multi-rotor LCD Flight Control Board is a great choice for a low cost flight control board with gyros and accelerometers. It is under $30! There are lots of other good alternatives, some of which are listed here.
FPV Flying – I recently got into FPV and spent $230 for a DJI Naza board because it has excellent altitude hold and very steady leveling. The altitude hold makes learning FPV much easier. The Naza is also very much a plug-n-play type board that doesn’t require a lot of configuration or tuning.
Expert Pilots – A more experienced pilot who wants to control everything with the sticks and do acrobatics may do just fine with a $15 Quadcopter board.
Turnigy Nano-Tech Lipo
Lipo Battery $20
Batteries also come in lots different price ranges. The C rating is important to insure the battery can deliver enough amps. Most of the batteries I have purchased are Turnigy nano-techs from HobbyKing. They are not super expensive and have high C ratings. The “nano” technology is supposed to have some added benefits. I don’t have anything to compare them against, but they cost a bit more than the B grade and lower priced standard batteries HobbyKing sells. The reviews of the B grade batteries aren’t too good.
I have both the 2200mah (less than $20) and the 3300mah (about $30) batteries. The 3300mah is quite a bit larger and heavier, but I get much longer flight times with this configuration.
HobbyKing 6 Channel TX/RX
Transmitter and Receiver $25
I started out with the $23 HobbyKing 6 Channel TX/RX and I love it. It is dirt cheap and works great. Unfortunately, it doesn’t have an lcd, but is configurable from a pc. Also, all of the trims are analog. For less than $25 it is a very good, cheap way for a beginner to get in the air. Also, it makes a great backup radio if you upgrade to a better radio later.
I recently purchased a Turnigy 9X, but haven’t used it yet. It has a lot more channels to maximize the capabilities of many flight controllers. It has an LCD and digital trims. Also, the ER9X open source firmware can be loaded on the transmitter for added functionality.
The Spektrum TX/RX systems are very popular among quad pilots. I considered the Spektrum for my second TX/RX, but they cost a bit more and the Turnigy 9X works with the HobbyKing 6 channnel receivers I already have, so I went with that.
Miscellaneous Hardware $20
Wire, connectors, zip ties, battery straps, heat shrink, solder, double sided tape, nylon standoffs, etc. are all needed to build you own quad. Not much to say here, except that if you plan to really get into the hobby, buy in bulk.
IMAX Battery Charger
Battery Charger $40
I started out with a $10 charger. It works fine, but takes forever to charge a battery. Recently, I purchased a $40 IMAX charger that has many more charging options and charges much faster. It comes with an AC power supply, which is nice. Unfortunately, my power supply died and they had to send me a new one. While I was waiting for the new one, I used the DC cables that come with it to charge off my car battery, a handy feature while in the field.
If I had known I was going to get into the hobby this seriously, I would have bought the $40 charger initially.