Hi all. Has anyone had any issues with the main blades de-tracking when left right aileron is applied? My blades are track perfectly in hover, but de-track slightly during left/right aileron input. I have checked all linkages, and they are all good length-wise. I have noticed a small amount of play with the washout assembly. Has anyone had any issues with the SDX washout assembly in the past? Could the play in the washout assembly cause blades to de-track with aileron input? Its only just started to happen. Cheers - Adam

I would inspect the dampeners on the spindle as well as your thrust bearings in the grips.

The washout arms do have ball bearings so some play will be present, but excessive play should not be. The bolts should be nicely snugged up without any binding on the bearings, and the mounting bolts should not be loose.

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Hi. I have noticed that the two small rods that slide up and down on the centre hub with the washout block is not quite flush. If I move the washout block, the two rods move left to right etc... in the groves of the centre hub. Could this also cause the de-tracking?

Also check that your ball links are not loose or have been sized too much with a ball link sizing tool. If the airframe has many hours of flying on it, inspect the steel balls themselves for wear. They will develop grooves from the grit and grime of flying over time.

Again, I suspect dampeners, thrust bearings, or spindle/grip bearings.

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Do the checks that Tyler suggested just to make sure. In hundreds of flights I've never seen much if any wear in the spring rubbers in the head block.

Does the machine run smoothly with no vibration in the hover and when you kick the HS up?
What blades are you currently running?
Do you have a spare set that you can put on to verify that the issue will translate to another set of blades?

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May I also suggest you check for a loose ball link on the blade grip, they can back out and loosen up, strip threads in the plastic grip or reside in a blade grip that is fractured in a way that is not evident unless the ball link is under stress.

Also ensure all your swash ball links are secure.

Look for play between the inner and outer swash plate parts. A damaged or worn swash can cause odd results that change with loads on the head.

Are you sure each servo is secured firmly and equally into the frame, and each is mounted with the same servo rubber hardware and brass bushings?

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Hi All. I think I may have found the issue (maybe). I have noticed that there is a little play in the swash plate bearing. I'm going to replace the stock swash plate with a new one. For good measure, I've also replaced the feathering spindle. I will go through and check all the ball links, and check for play and wear. Blade-wise, I'm just running the standard FRP 600mm symmetrical blades.

Hi TMoore. In a hover, the helicopter is perfect. Blades track perfectly in the hover, to the point where you can see not a single ripple in the fuel in the tank. Could it be that the blades are potentially NOT balanced?

Those are great suggestions you have gotten......

However, you don’t provide any “history” of the heli.....ie, is it a newly completed model ?? Rebuilt from a crash ?? Has the problem just appeared after it’s been ok for a while?? The answers to these questions may help to further diagnose the issue.

Minimally, I would do one thing at a time ONLY so that you can pinpoint the problem......

And if it were me, the very FIRST thing I would do is to try another set of blades as has been suggested without doing any other repair or mod. If the problem still persists, then move one to the other suggestions one at a time .....

Been there, done that and old enough to know better.....

JuanR. is correct, only fix one issue at a time and test methodically.

I agree with starting with blades.

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Hold the flybar steady and twist the blades out at the end of the blade and see how much play there is in each one.

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Hi all. With regards to the history of the heli, she has never crashed, kept in immaculate condition (my military career OCD helps that), and is about 12 months old. However, just last night, I do recall one day coming home from about 2 hours worth of flight time, and as I removed the heli from the car, due to wind, the car door closed, and did knock one of the main blades. No damage to the blades visibly, but now that I think of it....?

All your questions about the swash and washout base will not cause blades to go out of track. It will either be loose ball links or notchy thrust bearings in the blade grips.

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I'll try new thrust bearings. Would you recommend greasing them, or just a nice coating of machine oil?

Grease, thicker the better. You can try removing them, clean them and re-grease. If nothing else any notches that have developed will be in a different place so might cure your tracking issue.

60% of the time, it works every time!