Lomcevak Duck

My Feedback: (14)

Moderators: I posted this in the Futaba direct support forum and here because I want to get some other 9C/8U users' ideas and discussion here outside of Futaba reps.

I own a Futaba T9CAP purchased new in 2002 and have had no problems until recently. I am running a Futaba R149DP rx and Futaba S3010 servos all around, on 6V. The rx has never been in a crash, and the servos were all installed new and have about 10-15 flights on them in this plane. I have one aileron on ch.1, and the other aileron is ch.7 slaved to ch.1. About a week ago on the third flight of the day I turned on the plane and tx and one aileron (slaved, ch.7) was deflected about 30 degrees. No settings were changed, range check is good, voltage fine, servo is not stripped or weak, and it operates normally. I am using Dubro oversized servo arms made for Futaba servos, and they were tight. I don't believe they slipped, as the previous flight was uneventful, and no one else tampered with my plane or radio between flights. After I removed the servo arm and repositioned for center, no further problems occured. I have cycled the power several times and have failed to reproduce the problem.

I have seen this problem on another setup I previously used, Futaba T8UAFS with R127DF and S148 all around with standard Futaba servo arms, and 4.8V battery. The problem was very rare, occurring maybe once every 20 flights. The problem occured at power up, never during flight, and the fix was always the same, manually resetting the servo arm for center. In this case the problem was assumed to be in the tx and it was sold and replaced without ever being sent for service.

Ever heard of this before or have any ideas what might cause it? I hate to send a tx in for service when I can't even replicate the problem.

Thanks, Steve

Edit: Pushrod slipping can be ruled out as well because in both cases a 2-56 metal pushrod was used, threaded on one end, z-bend on the other.

LesUyeda

Is Channel 7 on a knob that can inadvertently be moved slightly??

Les

Lomcevak Duck

My Feedback: (14)

No, on the 9C channels 5-9 can be used in mixes or alone, with or without a switch assigned, and I do not have a switch assigned to channel 7. It is simply slaved to channel 1.

Danh4

My Feedback: (5)

I had a similar problem with a plane where occasionally the ailerons would deflect at power up like you described. The plane has an Airtronics receiver but I was using a Y-harness to connect the aileron servos. I recently changed two things which seems to have cured the problem- I got rid of the Y-harness and used 2 channels for the ailerons and repositioned the antenna from the bottom of the fuselage to the top of the fin. It's just a gut feeling but I think moving the antenna may have been the real cure. I had different glitches with this plane when I originally had a Futaba receiver in it and I thought the receiver was the problem which is why I switched to Airtronics gear. Now I think it may have been the antenna position all along.

Dan

Gulliver

I had exactly the same poblem and it drove me bananas until I discovered that the reset condition on the 9Cassigns ch7 to VR-C. Depending on whether VR-C has been moved, the aileron is offset on power up.