rockhouse

My Feedback: (5)

My Raptor 60 w/OS70 has a tail issue. First flight is fine for about 4-5 minutes then the tail sort of pulses when hovering. Until then the tail is rock solid. I have swapped gyros ( from a JR 500t to a 401 & back), swapped tail servos (both digital), & yes the gyros were set to high speed servos. The drive train has no visible issues & minimal slop. I am beginning to think that the engine is causing the problem. There seems to be a slight change in tone. Mixture is good (lots of power & cool rear case). Running Cool Power 30% heli. Could worn ball link balls be causing this?

RCer22

More than likely you are too lean and the gyro is picking up on it after a few minutes of flight.

BarracudaHockey

My Feedback: (11)

If the engine is changing tone have you checked your clunk lines? If its leaning out they could be on thier way out, especially as the flight goes on.

rockhouse

My Feedback: (5)

Thanks for the help!
I don't think it's the clunk, the tank drains fully during flight. I don't think I'm running too lean - lots of smoke & a cool back plate. Is it possible that the midrange needle is too lean? Could this be a gyro setup problem?

Thanks

RCer22

Worn ball links are either worn or they aren't. Maybe after a few minutes of running and as the tank empties it's starting to run lean. Richen it up some when it begins to happen and you will know.

rockhouse

My Feedback: (5)

The ball links were worn. I've changed them. No difference. Gonna try running a little richer. The 70 has a mid range adjustment. Is it possible that that setting is too lean? After 1 min. hover I can shut it down & hold my finger to the back plate with little to no heat. Ambient temp. is in the 50's.

RCer22

A cool engine can still be lean. Although being lean might be your problem I would set the mixture a few clicks one way or the other to see where you are on the settings. If your engine sounds like it's teetering between rich and lean the gyro could be picking up on that. If you do have a mid range set screw try setting that one first. Favor the rich side rather than the lean side. You can still back off on the gain to see if that gets rid of your problem. Also make sure the revo mix is turned off in your radio. Did you set your mechanical trim in non heading hold? There is a small chance that if it isn't set up right it can cause a problem though not likely. Check for smoothness in the linkage and make sure the gyro is not in contact with any of the frame parts. It should be on foam and be able to move slightly. Even a stretched or taut wire can transmit vibrations to the gyro.