What values have beta testers/pilots been found to be satisfactory for the RV-8? I did my initial flight test on my RV-8 autopilot today and so far haven't found the 'sweet spot'. I have a FltDek180, 2 servos, and an AP74. My heading wanders about 10 degrees left/right and altitude wanders 50-100 feet either way. I've tried torque values from 50 to 100 and sensitivity values of 4 to 25. This was over 2 1/2 hours of flight testing. The closest I've gotten to was with the roll servo set at 55 for torque and 8 for sensitivity, but it still wanders as I said. If I set sensitivity at 10 or higher, it will occassionally quickly twitch back and forth in roll. The pitch servo set at 70 for torque and 7 for sensitivity is the best I could come up with, but it still hunts altitude about 50 feet either way. If it gets more than 50 feet off it seems to use too much pitch for correction, varying pitch as much as 5 degrees above and below the horizon, overshooting the altitude, and then becoming unstable because of greater and greater atlitude excursions. I'm thinking it might have something to do with the AHRS accuracy. When hand flying the only way to hold altitude accurately by reference to the instrument is by using the pink vertical speed trend bar. The horizon line on the instrument isn't always referencing zero vertical speed. If the pitch servo referenced vertical speed trend, it should work very well, but if it's using zero pitch on the artificial horizon, it's not going to work very well. I don't plan on using this instrument or autopilot for IFR operation, but I hope I can fine tune it a little better than it is now. Anybody out there that has numbers that work on the RV-8, please pass them along...
Thanks,
Scott
Thanks,
Scott