| Hi Paul,
The Tru Trak is working great since January 2010 when I starting to fly my Lancair. My AP is a DigiFlight II and I do not have auto trim. I also do not have trim speed potentiometer and the trim is really very sensitive, just a fast tap on it to trim. The problem I found in one last trip at FL 9.5 is that in the ALT HOLD mode the AP was not able to maintain altitude forcing the plane slowly down. This did not happened from 8.5 down. The IAS was far above 100 kt I set to minimum. I'll fly again when back home (I'll be in Europe up to ends of April) and try to better understand what is happing.
Thank you for you interest.
Silvio Novelli
Lancair 320 PP-XSN +55 (14) 9.9614-3129
On 19 Jan 2014,w 12, at 11:07 AM, Paul Miller wrote: Silvio, the servos are not really altitude sensitive but if you have a pitch trim that has reduced voltage for speed reduction, that can be suspect. At altitude try and see if pitch trim operates by gently holding very light pitch up or pitch down while in altitude hold mode. You should get a response within a second or two from pitch trim. Without pitch trim, you cannot control pitch. Have you a reduced trim speed potentiometer?
Paul Legacy tru trak I also have a problem with my Tru Trak, it is not able to hold altitude above 9000 ft. Any comments? Bob weight is there to better stick force. My recommendation is to keep it.
Silvio Novelli
Lancair 320 PP-XSN +55 (14) 9.9614-3129
On 18 Jan 2014,w 12, at 11:41 AM, John Barrett wrote: Bob weight is there to balance the control surface . Out of balance can carry risk of flutter. Be sure to research before changing that relationship.
My Tru Trak autopilot altitude hold is inconsistent, and opinions are that the servo had difficulty working properly because of the mass of the bobweight on the elevator idler arm. One possibility is to remove the weight and expect more pitch sensitivity (lighter stick force) in turns. Has anyone found other alternatives? What if the mass of the bobweight is reduced? My servo is behind the seat and connected to a ring clamp on the elevator control tube with a smaller, roughly parallel, rod with bearing ends. Jack Dysart
|