gy 401 drifting

[hoagman]

Hi Everyone,
I went to fly my heli today and out of the blue i noticed that the nose of the heli was turning to the right while in HH mode.Any ideas out there why it would start to turn to the right.No crashes with this gyro and can't seem to find any other problems with heli.
Thanks

[Seeker]

Make sure when you initialize your gyro that you're not moving your heli. Let it initialize first.

I had this problem with my TRex. I would plug the battery in while holding the bird instead of letting it sit. The gyro did not initialize properly.

[flyinfool]

Also now that temps are getting colder, you must let the temp of the gyro stabilize for at least 15 minutes to the outside air temp before the first flight.

[WJackson]

make sure rudder trims are centered. Along with everything else! :D

[wren1702]

If the red light is solid and it continues to drift.........you may have a vibration problem.

[Striker]

Mine has this same problem and I have noticed the tail vibrating a bit while I'm hovering. What is the solution to this problem?

Right now I have my trim set 3/4 of the way to the left just to keep it from drifting.

Thanks,
Eric :shock:

http://www.expertmagic.com/

[Pinecone]

I had a drift problem because I had the ball to close to the shaft (S3154) and the limit was set up at 140 and still didn't get to the ends of travel. Moved the ball out to close to 8mm, and reset limit to 90 - 100 and drift was solved.

[BarracudaHockey]

Striker you should not have any trim or sub trim on your rudder channel with the 401.
http://www.futaba-rc.com/team/team-tip-002.html

[Striker]

AHHHHH!!

That must be my issue. I think I am having just slight turning to the right so I correct a little each flight and then the gyro sees this as the startup value next time.

Thanks for the link :)

Eric :shock:

http://www.expertmagic.com/

[spork]

Striker you should not have any trim or sub trim on your rudder channel with the 401.

This is absolutely true, but I fear he may still have the drift after fixing this. Striker, please post your results if you would. Thanks.

[Striker]

Hey Guys,
Alright so I tightened my belt and centered all the trim and sub trim. Everything is working much better now but I still have a slow drift.

I went to my servo display screen in my JR 7202 and I see the rudder servo is off to the left even tho eveything is centered. What could be causing this? Should I use sub trim until it is centered?

Thanks,
Eric James :shock:

http://www.expertmagic.com/

[BarracudaHockey]

Check your flight modes, you probably have trim enabled per flight mode and one of them is off.

[spork]

Also, you're sure you have no revo mixing enabled - right?

[jbrobin]

I am having the same problem. When you figure out what fixes it please let me know. I have the exact same setup. gy401 ect. Nose drifts to the right in the hover also.

[spork]

I have a bad feeling the gyro is not properly initializing to the zero-command rate and zero yaw sensed yaw rate. I hope I'm wrong - but it smells that way. Certainly vibration and temperature are a couple of likely culprits.

If my bet is right, you'll be able to trim the drift out once you're in a hover, and still get all the heading hold benefits. I'm not claiming that's a great answer, but I suspect it's the case.

[wren1702]

I chased the same problem forever, until a couple of the Freaks helped me out. My problem was vibration coming from the tail. You couldn't see the fins vibrating while in a hover, but we held the heli down and ran it up while touching the tail fin (Exercise extreme caution!) and you could feel it vibrating like crazy! Replaced (read...upgraded) tail rotor hub and balanced tail blades, problem solved. :mrgreen:

[spork]

My problem was vibration coming from the tail.

I do agree with Wren that vibration is a likely source of the problem. If you want to rule that out without replacing a lot of parts you can try a couple of things. You can mount your gyro on a MUCH softer mount, and you can mount a mass (like a little lead tape-a-weight) on the gyro case. This will almost certainly isolate the gyro well enough to determine whether vibes are your problem.

If so, remove the weight, re-mount your gyro as it was, and chase down the vibration. If not, remove the weight, re-mount your gyro as it was, and scratch your head some more. :mrgreen:

[flyinfool]

I like that one Spork. I never thought of putting an extra mass on the gyro before.

[spork]

I like that one Spork. I never thought of putting an extra mass on the gyro before.

Thanks. I use that same trick for stabilizing my crappy little CVS video cam. The thing is way too sensitive to vibration. I'd like to leave the batteries out and power it from my LiPo, but the batteries help so much with the vibes, that I decided to leave them in. That and a really soft mount.