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Saturday, February 11, 2012

FPV

Homemade Head Tracker

What it takes to get Started in FPV Piloting:

If you are new to wireless video the first thing is to purchase a wireless video system that will fit your needs from a good FPV vendor like HobbyKing.com, etc.... First you must consider what type of FPV piloting you will be doing, long range (2 miles or more) or short range (less then 1 mile). Long range will require more equipment and a powerful wireless transmitter 500-1000mw (milliwatts) where shorter range requires less power like anywhere from 10mw to 300mw. More watts = further distance. For FPV pilots a 500mw system is the most popular since it can have as much as 2-3 miles of range without drawing lots of power like a 1000mw system. It's recommended to have more wireless video range then RC radio range so if you happen to lose the RC link at least you well be able to see the aircraft's view and OSD info. Helpful if the aircraft should go down making retreiving much easier.

We well assume that you already have an RC Plane, Helicopter, Car, Boat, HAM lic. and are familiar with the radio controlled hobby.
If not we suggest you start with a Radio Controlled Aircraft/Vehicle and become good at controlling it before you ever try FPV piloting. Even though some hobbyist may think it's easier to control a RC aircraft/vehicle through the use of FPV it might not be for you. Take your time getting into this hobby as it can be addicting:).

What you will need to get :

1. Small light weight security type color cameras like the KX-131(5 volts), WD700N (Hi-Res 12v) CCD imager is preferred. Available from site like:(HobbyKing.com)
There are 2 types of camera imaging sensors used, CMOS and CCD. Both have positives and negatives for FPV. Most CMOS will adjust to brightness and contrast for each pixel giving a better picture then CCD, along with using slightly less power. The CMOS camera draw back is it scans each image line by line which can cause waves or ripples in the video if there are vibrations from the aircraft. Also sudden turns or movements can look less natural.
CCD cameras are more popular with FPV pilots because they capture the image frame by frame which allows for better picture when there's vibrations and quick movements. They handle low light conditions better then CMOS and have more pixels for the size (more pixels the better the resolution/clearer picture). The draw back is they consume more power along with blurring when going from dark to bright objects like ground to sky (CCD cameras like the WD600N don't have this issue). 5 volts and 12 volts systems are common. Some prefer 5 volts because of the other electronics they are powering use the same voltage like servos and such so they might share the power source (not recommended). Also most 12volt cameras are really stepped down to 5 volts with a built in regulator.
12 volt cameras are popular because a separate power source like a 3cell 11.1 volt lipo battery easily powers the system along with the video transmitters which now are mostly 12 volts. 12 volt systems are becoming the most popular and are recommended.


2. Wireless video Transmitter and a matching Receiver
There are a few frequency bands to choose from when it comes to purchasing a wireless video system, 900MHz, 1.3ghz, 2.4GHz and the newer 5.8GHz.
Most popular video transmitter as of now is the 900MHz with 500 milliwatts due to the fact it has more range at the same power draw as the other bands. Gets around obstacles better then the other frequencies like trees and buildings. Works with all RC radios and the newer 2.4gHz radios like Spektrum/Futaba/JR without causing interference. The draw back is some countries do not allow 900MHz for public use so 1.3GHz or 5.8GHz is recommended. Milliwatts are important for range so if your going to fly at a far distance then 500mw is going to allow for 1-3 miles/2 km Line-of-Sight, where 10mw will give you much less like 200-300 yards. Some countries do not allow more then 10mw so check your local laws. Wireless video sellers well also have a matching receiver to go along with the frequency you choose.


3. A monitor 7" display or larger. The larger the monitor the better. Or video goggles with a minimum resolution of 640x480 if you plan on using an OSD and want to be able to read the text clearly. Most popular are "Fat Shark" and "Head-Play" brands. If using a monitor you will need to block out the sun light from hitting the screen. Most FPV pilots build an enclosure like a shoe box around the display and then cut a opening for viewing. (note: Fat Sharks are 2.4ghz wireless goggles so there not recommended when using 2.4ghz radios.)


4. A separate battery to run the video equipment inside the aircraft is highly recommended. Using the aircraft's battery can make for poor video and if the battery runs out you will lose your video feed (Video Drop Out) making it impossible to see where the aircraft might land/crash. Try to keep all your wireless video equipment using the same voltage like all 5volts or all 12volts, most companies have both. 12 volt systems make the most sense because a 3s 11.1 volt lipo can power these systems without having to use a voltage regulator like 5 volt systems need. It's not recommended to power 5 volt wireless gear with the radio RX power source even though they have the same voltage. Doing this may cause glitching and/or shorter radio range.

Not all wireless systems are "Plug N Play" so some soldering skills maybe needed depending on what you purchase. Some systems come with bulky RCA/BNC stereo/TV connectors which most serious FPV pilots like to replace with smaller, lighter servo type connectors especially if space and weight are a issue. Most FPV plug n play systems use servo connectors that match what most OSD's and data loggers use.
WDR700 CCD color camera is one of the best.

Basic Plug n Play 900MHz video system from HobbyKing


A good platform for FPV is a well built RC Aircraft/Vehicle keeping in mind that you will be adding more weight for a Video Transmitter (about 2oz), Camera (1.5oz) and a separate power source (battery 2oz) and that's just the basics.

Another thing to consider is the type of aircraft. Electric RC has come a long way in the past few years with the newer Brushless Motors and Lipo batteries that allow for more power and longer flights. They're recommend for FPV over gas (nitro fuel) and don't have the mess associated with fuel.

Trainer aircraft can make a good platform and some modifying of the equipment location may be necessary to keep the center of gravity (CG) correct along with a more powerful motor, larger prop, etc..
Some popular planes for getting started in FPV are the Multiplex (MPX) Easy Star and Skywalker which are made from a durable EPP/EPO foam. There's also the electric Easy Glider, HobbyKings FPV-UAV-168, GWS Slow Stick, Flying Wings, EPP-FPV, etc... Even though you might be a expert flier we suggest starting with something like an Easy Star when first learning FPV piloting.

It's also a good idea to have a plane/heli dedicated just for FPV as changing back and forth will cause you some headaches. Once you have the aircraft chosen you will need to install your wireless camera gear. It's a good idea to keep the wireless video TX 6" to 10" or more away from the planes RX and antenna (your results may vary..always Range Test 1st). If using GPS try to keep the GPS antenna far away as possible from the video TX. When ever possible keep servo wires separated from video wiring. Also use twisted or braided servo wires. This will help keep any interference down to a minimum or none. Some of the best FPV camera placement is usually in the cockpit area for planes and between the skids for heli's.
Some FPV pilots prefer to see part of the aircraft's nose and some don't want anything but the view so final camera placement will be up to you.

Another great way to practice FPV is to use a simulator like Great Planes "Real Flight" G3/G4/G5 RC Flight Sims which allow you to fly from the cockpit view (not able on photo fields sims like the Phoenix). Using the simulator for FPV helicopter practice helps tremendously, not to mention cutting down on repairs from crashes and saving money while learning.
Most popular recommended set-up for basic First Person View, FPV piloting:

1. **Multiplex Easy Star with a brushless motor (2400kv-3000kv, 6x5apc prop) and matching ESC (25-35 amp) Hi-Tec HS-81 servos**

2. Futaba , 9C,10C (10channel), 12Z, 14MZ if you plan on using a Plug n Play head-tracker (Head-Trackers not recommended for beginners)

3.SN-555 / WDR700 (12v) camera (mounted on Pan & Tilt servos if using Head-Tracker)

4. 100mw to 800mw 900MHz wireless audio/video transmitter with whip antenna.

5. Matching wireless receiver with a patch antenna (standard whip is fine for short range flights under 2000')

6. 3 cell (for 12v) 1000mAh or higher Lipo battery for powering wireless video gear

7. Video goggles or monitor with good resolution (640x480 min. if planning on using a OSD.)


Note: If using a 2.4ghz radio like Spektrum/JR/Futaba it will be necessary to use a 900MHz(.9GHz) or 1.2GHz, 1.3 GHz (UK), 5.8 GHz wireless video system and not a 2.4GHz system due to interference with 2.4GHz radios.

Notice: Video Transmitters can get HOT and need cooling like good airflow or a heatsink or fan. Never power a wireless video transmitter for more then a couple of minutes without proper cooling as doing so may ruin the range of the transmitter causing it to be much shorter....but it will still work so always range test if there is a chance it has been overheated.

Your First FPV Piloted Flights

Once you have done a range test you should fly your new FPV plane in normal view until you get the hang of how your new plane flies and get all the trims set to your liking. Record your flight and review it so you'll be familiar with the surroundings and you'll also be aware of any video drops/static before flying FPV. When you feel comfortable to move on to FPV it is recommended that you don't use Head-Tracking (HT) with a pan and tilt set-up for your first few FPV flights and that you use your camera in a fixed position Pointing Straight Ahead (don't point camera down). This will help with visual flight (VFR) in allowing you to put the horizon in the center of the screen during level flight. You will be better able to till whether your climbing, descending or banking a lot easier.
This will also help you become oriented with your aircraft and what to expect while flying FPV.
Another good idea and can't be said enough is "Have a Spotter" to watch your aircraft. Having a spotter is a important FPV tool and if possible have your spotter hooked to your radio with a buddy box/trainer cord. If you become disoriented or lose video feed you'll be able to select your trainer switch allowing the spotter to take over your aircraft until you can regain it. Don't fly over 400' altitude (in US) keeping in mind that your spotter must be able to see your plane and it's orientation. Try to keep level flight and refrain from doing loops, rolls, hammer heads, etc.. until you become a good FPV pilot.
Piloting by FPV takes a lot of concentration and might seem hard at first so if your thumbs (fingers) are shaking that's normal for most newbie's but should go away after a couple flights.

Don't fly to far!!! A lot of first time FPV pilots fly out of radio range on there first flights and it's easy to do so Stay Close by and expect shorter flights since most new FPV pilots also tend to use more power draining the battery faster.

Practice flying slow at a safe altitude (100'+) and Close by (400'-).

The possibilities are limitless



View some fantastic video shots taken via FPV somewhere in the Alps. The reason why specific details are missing from the write up is probably no accident, seeing that the flying appears to be totally illegal judging  from present RC club rules.


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