20141130 F450 build notes Todd Stellanova
Pixhawk PX4FMU v2.4.5 or later with an appropriate 3s-6 power module (depending on your battery choice)
My current favorite is the HobbyKing "HKPilot32" which is HobbyKing's Pixhawk 2.4.5 build. I've had good results with their quality, though you can only sometimes get them from the HobbyKing USA warehouse, otherwise you need to order from Hong Kong HKPilot32 I no longer use any fancy vibration-isolating mounting system for the PX4FMU itself-- I simply cut the sticky foam provided with the PX4FMU into four small squares and stick them to the four extreme corners of the bottom of the FMU. I then stick the FMU inside the cage formed by the upper and lower decks of the F450, to provide additional crash protection.
For a compact GPS I prefer the Ublox LEA-6H, which you can sometimes get bundled with a Pixhawk. I do not recommend the Ublox Neo 6M or Ublox Neo 7N GPS units. They're cheaper but don't perform as well in my experience. Depending on how you decide to build your F450, you probably want a foldable GPS mount ...this allows you to fold down the GPS + compass antenna pod for transport.
You'll need at least one pair of SK1000 915MHz telemetry radios (or equivalent) for communicating between the ground control station and the drone. The connection options for drone-to-radio and ground-computer-to-radio are seemingly endless, but assuming your ground control is an android tablet with a free USB OTG port, you could use this HobbyKing telemetry set
Oftentimes you can find most of the essential flight controller stuff bundled up. For example, I've had good luck with the "GOODLUCKSELL" seller on ebay with their Pixhawk bundles
Here's a decent Goodlucksell Pixhawk bundle
You don't really need the PPM converter unless you have a crappy RC transmitter / receiver, which I do not recommend.
For RC receivers, it seems like the best deal right now is the 16 channel FrSky Taranis You probably want a Mode 2 transmitter (throttle vertical, on the left), which is what most pilots in the USA use.
You can use this with a FrSky X8R 16 channel ACCST receiver
(The X8R receiver outputs S.BUS, which the Pixhawk can take directly as input without using a hokey PPM converter.)
The cheaper option is to get a Turnigy 9XR
and install your own FrSky-compatible radio module...that bundle also comes with a X8R receiver which is convenient.
I most frequently use a 9XR transmitter with a lightweight FrSky D4RII ACCST receiver
It supports CPPM output, which the Pixhawk also supports, but you may need to reflash the D4RII firmware, which is a pain. Also, the D4RII doesn't support as many channels as the X8R, which might be a limitation if you want to eg activate lights or cameras. I wouldn't recommend this route unless you really need to shave weight and don't mind the channel limits.
For the F450 class and a 3s system, I like these Sunnysky 2212 980kV motors
I run those with 1047 or 1045 propellers such as these carbon fiber 1047 props The carbon is durable (suriving the occasional drone toppling over onto dirt) but very dangerous at high RPM. You might want to pick up a few sets of nylon props to experiment with before upgrading to carbon.
If you decide to run at a higher voltage, eg 4s or 6s, you'll need to ensure that your ESCs can handle it, and that your props are sized appropriately. The "kV" rating of motors is related to the RPM you will get per volt, and generally the higher the voltage, the shorter the prop you want to use. The combinations of props and battery voltages are endless-- rcgroups is a good source for info on combos people have used successfully.
I've used a bunch of different ESCs with varying success.
My current favorite are these Spider brand 30A opto ESCs...one nice thing about them is they can handle 2s-6s range
Another decent choice is the HobbyKing Afro 30A ESCs
Note that these ESCs don't really provide a BEC or UBEC (5v or 6v power supply) function. If you need that, for example to drive a gimbal, get a separate UBEC. For example, these dual voltage UBECs have started appearing on HobbyKing and eBay
The quality of these varies quite a bit, even from order to order from the same vendor. The cheapest USA source I've found is F450 frames from emilyandlily
You can safely solder the ESC power leads straight to the bottom PCB on this frame, for power distribution. If you're uncomfortable with that you can use a separate power distribution board or "octopus".
If you're going to carry anything in the drone's undercarriage and you don't want to land on it, for landing gear these simple Nylon skids for F450 are a good option that seems to work on F450 frames from multiple vendors. I haven't had much luck with the leg extensions that attach to the ends of the motor arms...I always seem to snap the arms, which are a pain to replace. The underbody skids are a bit bouncy/springy, so they take some practice to land softly without toppling.
I generally use these HobbyKing 4500mAH 3s Turnigy nano-tech batteries, though a 3300mAH or even 2200 mAH will work fine as well, you'll just get fewer minutes of flight. Note that you'll need some kind of power connector adapter to connect with the stock Pixhawk power supply (which has an XT-60 connector).