Aero Cruze 100 Settings Tweaking

[Mark White]

I just installed the BK Aero Cruze 100 in my 1974 PA-28-180. I have done some research and followed a thread in here on the settings used to overcome idiosyncrasies for each individual installation. My problems are concerning Altitude hold and tracking.
When set to altitude hold there is a constant porpoising plus or minus 200 feet of set altitude. I have considered a static system problem but saw a few posts that had the same problem and were able to negate the severity by using vertical setting adjustments. I just finished my annual and re set the cable tensions to spec.
Also the autopilot has a problem turning to a track that is more than 40 degrees from the original track. If you say move from 90 degrees to 180 degrees it will turn about 30 degrees toward the new heading then stop short and seem to hunt and adjust then after a minute or so slowly start moving again to the new setting.
I am soliciting help in interpreting the settings and directions i need to go based on other people that have addressed these problems. I plan on calling tech support Monday but wanted to see if there was any knowledge I could tap in this forum.

 

[Mike W.]

I installed an AeroCruze 100 in my PA28-140 recently and had a similar problem with the turn. My airplane would track a heading, but then start a shallow right turn that got progressively steeper. The screen showed the proper desired heading and it showed that the airplane was in a turn...it just wasn't correcting. BK support was great. We worked through several different setting and hardware changes and it never corrected the problem (switching the servos and new control head). I was referred to an engineer that asked me to check cable tension. I told him I had the airplane rigged prior to install, but I decided to check it again. All cables were right on... Then my A/P wanted to put it through the ground checks again. We noticed that the cable looked like it was contacting the airframe during a left turn. He removed the foam/rubber cover where the cable went through the airframe and confirmed that it was actually hitting the airframe and causing enough friction to stop the servo. He verified that the cable was not damaged and began trying to figure out how to fix the problem. In the end, he switched the connection point on the cable clap from the bottom row to the top row. That then allowed the servo to move full distance without hitting the airframe. Test flight was perfect. I guess the friction was causing it to not be able to make a left turn...hence the slow right turn. I hope this helps someone.