611 Problem Help!!

[thenewguy]

I have my 611 set up just like my old 601. My buddy Mr Travis Vtec helped me. So I know the set up is ok. The problem is when in a steady hover the tail kicks one way or another about a foot. The first time it did it, man scared the &$^% out of me. It only does it every couple10 to 12 seconds. It's not hunting. It looks like its going to spin around at first. Then stops. So its a kick. You'll be hovering and all of a sudden kick 6 inches to the right and stop. This gyro is new with 2 hovers on it now. If I reset it will that help.? How do I reset the gyro? It's on a new Stratus. it's also not going in to lock out cause I still have full control of the rest of the heli. Also it run by a 14 mz if that helps. :(

[tnreefguy]

It sounds like the motor is real rich. I assume the motor is new as is the heli. If it is lean it a click or two. also make sure that the sensor is firmly attached to its pad and metal piece but not too tight. I would also check the gear mesh of your tail drive system. It might be skipping teeth.

[vitek]

I've got Chris' machine. I'm going to do a look over and maybe a test flight tomorrow. I'm pretty sure it is the needles, but I could be wrong.

[thenewguy]

Travis is THE MAN !!!!!!!

[thenewguy]

Well it's fixed! Thank God!! It was the gyro mounted to close to the starter shaft. I moved the gyro to the battery plate and the kick went away. Travis helped me find the problem. I was able to fly with him there to see it first. I had read a post about others having this problem on RR. So thought I would give it a try. Thanks all for your help. Hey Russ, I look forward to flying with you again this summer. Now I cant wait to try my Stratus out. :D

[Russ McC]

I look forward to it to! Glad you got it sorted out, have fun and be careful :glasses2:

[Wa11banger]

I had the same problem and it started occuring on all of my 601's and my 611 roughly at the same time so I suspected my TX. Then come to find out it was the gyro tape.. Don't use the JR gyro tape when its cold out lol.. That tape works great in the summer and is more than sufficient and I dont think an elephant can pull it off but when it gets cold it gets hard, might of well just epoxied the gyro sensor to the frame. Replaced with Futaba tapes and now all is well again. I did some tests taking the JR tape inside to warm up and it got nice a plyable/flexible again.. Took it outside hard as a brick again. But unfortunately I changed out engines, gyros, gyro tape( yupp changed it as suspect but replaced with the same stuff so I no longer suspected it), Rx's, Tx's nothing seem to fix it until I was setting in the garage about to start a mosh pit out of my helis and noticed the tape was stiff. Then the little light went on. Just something to keep in the back of your mind through the winter months

Rick

[thenewguy]

Well the problem has come back now. After about 4 gallons of fuel threw the heli. I noticed the tail was starting to twich during flight. Not that big of one, you had to watch close. It has started getting worse. I checked the sensor to make sure it was secure. I have it taped and velcroed with a strap down. It's not going anywhere. I thought it might be excesive vibration from the motor. I did not check the run out when I built the heli. So I check the run out today at work. I'm at 6 thou, the stratus manual says +/- 2 thou. So I'm alittle over. I went ahead and ordered new ceramic bearing for the motor. After I put them in I will fix the run out. I want to reset the gyro also to see if that helps. Can someone tell me how to do so? Also any coment or help would be great. Keep in mind the heli has been flying great for awhile now. I have also checked all the links and stuff on the tail to make sure is all well.

[vitek]

I know you can reset the 601, and I'm sure the 611 is the same. Call me or bring it over and I'll walk you through it.

Travis

[DavidH]

Personally I would not mount the gyro where you have it mounted. And if you have it strapped down tight, the foam under the sensor is not being able to do what it is suppose to do. I would think where the gyro is mounted that if there is any vibration in the model it is being amplified to the gyro sensor. I would mount the sensor in a more secure location. If that is where you want to mount it as in the picture. At least move it back to where the plate is bolted to the main mechanics.
I don't think a reset is going to cure your problem. All a reset does is reset the settings back to default settings. You will have to set up the gyro again and I believe the twitch will still be happening.

David

[thenewguy]

I don't know where else to mount it. If I put it in the stock place, that is where I had the first problem. That problem went away when I moved it to where it is.

[vitek]

Chris,

If you remember right, David is saying the same thing I was when you mounted it in the front. I can't remember if you tried this or not, but you might try putting it back in the stock location and using the shielding plate.

It might just help to balance the fan and get it installed straight. I wouldn't think you would need to replace the bearings. That motor is pretty new.

Travis

[DavidH]

I would suggest getting the fan dialed in to under .001. Also here is another suggestion.
Don't know if you have been adjusting the needles. But I would think that Travis tuned the motor back in November and that also helped in correcting the problem along with moving the sensor. Now it is April and the temps are a little warmer. The motor is still probably rich from the colder temps adjustment. Just a thought.

But most definitely you want to dial the fan under .001. I doubt the bearings are the problem also. If your mounting the sensor directly on carbon fiber surface. You definitely want to use the steel plate provided with the gyro. That is what it was designed for, to insulate the gyro when mounted on a carbon surface.

David

[thenewguy]

I am replacing the bearings cause I had the motor out, and I like nice bearings in my motors. Thats the only reason. I plan on dialing in the fan under .001 thou and putting the gyro in the stock location witht the metal plate and all. Should have it all done by the weekend. I will post and let you know how it goes.

[EricLarson]

Just saw this post.

If your tail is acting up with the gyro in the stock location it is vibration related.

As David said:

Fan .001 max run-out
Good gyro mount tape
Motor should be tuned close.
You should have no visual signs of vibration in the model.

If it drifts or kicks in the stock location there are 2 possibilities. Vibration or a bad sensor. I have seen a bad sensor also cause issues. Will here at HeliFreak had a bad sensor at a FF and we got him fixed up. His would kick 4-6 inches all of a sudden but otherwise it worked fine. Changing the sensor fixed him up.

All carbon airframes transmit vibrations very well and are not tolerant of bearing or run-out problems.

Good luck in finding the issue.

[WillJames]

Thanks again Eric. It was a hard kick in either direction and changing sensors did the trick. Eric was nice enough to take one off his backup machine and let me try it. Problem solved, same tape and I also strap mine down with Vercro.

We knew it was not vibs because I had already tried everything to make sure vibs was not it, my fan was balanced to 15K+ RPM and dialed in to less than 1/2 thousandth by none other than Shannon Davis. I also tried mounting my sensor underneath the radio tray at the advice of someone (I think it was Eric) and I still had the kick with it there. Then I replaced the bearings on the clutch stack and main shaft, etc, still had the kick and was getting pretty frustrated....

Not sure if this helps, but I would get my kicks when the disk was unloaded, it never seemed to happen nearly as bad when the machine was loaded.


Mac Hodges where I got the 611 a month before, replaced the sensor no questions asked.

[thenewguy]

Well it looks like I got it fixed. Worked on the runout for about 3 hours. The best I could get it was .002 at best. That made a huge differance in vibration. Remounted the sensor with the sheld in the stock position, and went and flew. I use the stock dubble sided tape that comes with the gyro. Had a drift right from the get go. The twitch was gone, but the drift was there. So I changed the tape to some good 3m stuff I have. Drift went away. It seems to be rock soild. I only flew one tank cause of the great wind here right now. But all looks well so far. :D Thanks Guys for all the help. I will keep you posted after I get acouple more flights on it.

[EricLarson]

When you dial the fan here are a few pointers.

- Make sure the bottom collet is not tight on the crank. It needs to move a bit to get things straight.

- You NEED to have a washer on top of the top collet before you install the nut. If you do not, you will probably never get the fan straight.

- Do not over tighten the nut. If you crank the heck out of it, you will cause problems.

- If you need to straighten the install, support the crank by the back with a 1 inch wood dowel or similar and tap on something that will protect the fan from damage such as a wood block.

.002 is ok, but really .001 or less is much preferred. You will save yourself a lot of headaches down the road by getting things spot on to start with.

take it easy,

[thenewguy]

Just to give a update. I replace the 2 copper collars that hold the fan on. Was able to get the runout under .001. Seems to have helped. Have a slight drift to the right on the tail. I'm going to play with different gyro tapes to see if it well go away. It was perfict for awhile, but the tape I use brook in half. The velcro strap was the only thing that saved it. Any suggestions on tape.

[DavidH]

It was perfict for awhile, but the tape I use brook in half.

I would guess you were using the foam squares that come with the Futaba gyros. That is a known problem. I have not used the Futaba squares since the days of the G501 gyro about 12 years ago.
I use 3M products 4408 double sided vinyl tape. This is the same foam tape that MA and Ace packages and sells. You can get it at Rick's R/C.


David

[Aviation addict]

Just a thought regarding the drift - Is the tail set up well mechanically to give zero drift out of AVCS mode on a calm wind day? I understand that even if you don't wish to ever fly in Normal mode it helps the Gyro greatly if the mechanical set-up is perfect (zero rotation in Normal). You've probably done all this.
Cheers.

[thenewguy]

I did do that. Thanks thou for some input. :D

[WillJames]

So you have any rudder trim in there? Not subtrim, but trim?