For those who are having problems getting TrackIR to work properly, a few tips from a battered and bruised TIR warrior.
1. Make sure there are no extraneous lights in the background that can interfere with the sensor reading the clips reflection or LEDs. Sunlight or bright lights in the background will often cause the sensor to get confused. When this happens it "tilts" (to use an old pinball expression). By that, I mean, the virtual head literally flips upside down and the screen goes kaflooey, to use another old expression, this time engineering.
If you look at the setup screen with the cross hairs that moves with your head, on the top left is a drop down box arrow. Click on that. You will see several views. One of these views shows the reflections the sensor sees as green dots. Any red is extraneous light that can cause interference. Try and remove as much as possible.
2. Calibrate, calibrate, calibrate. Don't just do a move your head and see if it works, calibration. Calibrate each axes individually. The default curves might work if you fly heavy iron and only stare straight out of the front. However, if you do a lot of pitch movements, looking up. Or behind you, 180 degrees, the default curves will not work well. You will need to move the pitch and yaw curves to a heavy vertical setting. The curves will look like a V. My pitch curve looks more like a checkmark. I want to see 90 degrees up but not down. So, I have my pitch curve fairly flat on the downward side.
The goal is to get your curves set so that your head movements will allow you to see wherever you need to see without moving the head so that the sensor cannot see one or more of the hat clip reflectors or LEDs. If this happens...kaflooey. There is another view on the setup screen that can help. It is the back of the head. This view shows you actual head movements AND the virtual head movements. So, you can see how much the virtual head moves when you move you head, say 15 degrees. To keep the sensors in sight of the receiver, you should limit your head movements to 20 degrees.
3. Those of you who suffer from vertigo. Use the smooth and speed sliders to get an even, not too fast movement of the virtual head. It can help with vertigo. Also, try the smooth profile and then modify it.
4. Set a button on your throttle or joystick to F12. I have the castle switch set where F12 is up and F9 (Pause) is down. Left and right are S and Shift S. to allow me to see outside, when necessary. If the screen goes kaflooey at a critical point, like just before rolling out 300 feet above the ground on a landing. F12! There, you just saved your life.
You can find YouTube videos posted by gamer kids showing how they set up their TrackIR. I know they helped me and gave me tips.
I consider TrackIR along with FSUIPC as an almost indispensable addon for flying in the sim.
