Duho...stupid tail wag

[chopstick]

I go with Sly.
Moving the ball in will give the servo more resolution, so it will be able to react in smaller steps. this way it will not oversteer fast.
mine is set on 10 mm. On a Ds650 fullsize servo.

[sly the dogman]

Did I also mention that Kyosho sticky pad is a good addition for holding a gyro down.
I have it under my DS760 and there is a difference...(just saying)

[maddog57]

Thanks guys. I've been really busy the last week or so and haven't had any time for helis. I have the 520 mounted, just need to set it up. Had to replace the AR6200 RX cuz one of the antenna broke off while I was working on the heli. Have a replacement mounted and bound, but now the CC75 ESC doesn't show a yellow light after initializing so I'll have to deal with that too (think I may need to set throttle end points again)

I'll post again when I get 'er going again.

Chris

[meherenow7]

Hi Chris,

Have you made any further progress on this problem of yours? I have the same issue and like you, have tried everything almost humanly possible. Mine wasn't the result of a tip over though, its just been like that from the start and it defies logic! Never had a problem setting up other helis before.

Thanks,

Mat

[maddog57]

Hey all, I finally had some time to work on Atom. I'm about ready to ditch this thing! Got the GY520 set-up and whadda ya know... the wag's still there!! Tried moving the tail servo ball in and out from the original position, but made no difference.

It's gotta be a machanical problem. Been thru three different gyros and two servos, so it seems it can't be electronic!?

I'm all out of things to try.

Mat I feel for ya, especially if yours has been wagging from day one. I wish I could help you, but as you've read, I'm not finding anything wrong either. Up til now, mine has been great.

Chris

[sly the dogman]

.....have you thought of stretching your 500. Looks like everything else has being done on this heli to stop it from waging.

A real pain man, I kinda know what your going throught, exasperating

[meherenow7]

Hey Chris,

Found this discussion from a guy with similar issue.

http:// myrcguide . com /index.php?topic=10694.0

After reading through to the end, the guy solves the problem by mounting the gyro in a different way and also securing the leads to the gyro.

So sounds like vibration issues. I think i'm going to try moving my gyro location and securing with the method this guy uses, can't hurt to try and don't have much else left to try at this stage!

Mat.

[maddog57]

Hey Mat good info find. Please post back and let us know what happens. I'm gonna try a new set of blades. I'm at a loss as to what else to try. I may stretch it as Sly suggested, I think that cured his wag, though I still don't understand how.

Chris

[sly the dogman]

Please understand, my heli was already stretched, so the longer boom did not resolve my problem, the stretch thing is just another idea.
I changed the wheel on the tail servo to get 7.5 instead of 13.5 from the center of the servo to the rod. I don't know why but it worked, meaning, that it did not work for you.
Lesser resolution, lesser gain and the DS760 is sitting on a Kyosho pad. It does have a slight drift nose right but I prefer a drift than a wag, in some odd way.

There's not many places you can install a gyro on these small frames and on the other hand the gyro has to accept the fact that its not setting where it is supposed too.

I imaging that the tail rod is in line with the boom and that the tail linkrod guides are both at a right angle. Do you have a spare guide that you can snap on real fast and kinda like split the boom in 3 parts, to get a steadier rod. At this point in time, weird ideas is all that's left.

Best of luck,

[leaverus]

omg! 2 months later and you still haven't figured this out? i woulda given up after 2 weeks max.

[Shogun71]

I have been able to get my tail gain to 84 on my dx8 and fail to be able to induce any sort of wag even with hard tail stops. I do have a drift though.....

[maddog57]

Originally Posted by leaverus

omg! 2 months later and you still haven't figured this out? i woulda given up after 2 weeks max.

you made me laugh with that one. It has been two months, but it's been off and on, maybe a total of three weeks total hands on time. Between work, watching our grand daughters, wife time, lawn work, etc., I don't get a lot of time for helis...unfortunately!

I hate to give up, I love my Atom. It's gotta be some stupid mechanical thing I'm over looking.
I will prevail!

Chris

[maddog57]

Sly, as always, thanks for the input. Yes, the rod is dead nuts straight down the boom. I've even tried moving the guides to various locations along the boom... no difference. I've never really liked the way the rod archs on the servo end, but it had always been fine before the tip over.

I'm still checking over and over for something... anything I could've missed. I now believe it's gotta be vibration induced cuz I'm confident I've ruled out the electronics causing it. Don't see any vibs in the skids or tail fin though.

Chris

[meherenow7]

Hey Chris,

Well just to let you know, i've had success, but it wasn't to do with the gyro. I changed location of the gyro and made sure it was secure. Same problem with the wag. So i tried the other thing suggested in that post I put the link to.

I took the main blades off and disconnected the rudder servo link. I strapped my heli down securely and then spun it up to half throttle. The i grabbed the tail control rod and tried to move it by hand. Well, it was almost impossible to move. Its like when the blades are spinning, it puts some sort of brake on and its not wonder it wasn't working right. So after investigating the tail mech a bit further, it looks like the slider sleeve has enough play in it so that when the blades are spinning and the centripedal force is holding the blade grips firm, the sleeve tilts ever so slightly and grips the tail shaft acting like a lock.

So just because its dead smooth with nothing running, doesn't mean its right.

Anyway, I replaced the tail shaft, slider sleeve and blade grips, then spun it up on the bench again and it was much easier to move by hand with it spinning. Put the main blades back on and took it out for a hover. Tail stayed almost perfectly still and with a bit of adjusting on the gain, is running sweet now, NO WAG!

So I hope that i've solved it once and for all and hopefully may help you with your problem aswell. Good luck.

Mat.

[maddog57]

Mat, thanks for getting back to us with your success. I'm really glad that method worked for you. I tried the link you posted but it doesn't work. But i did as you explained and mine too was almost impossible to move. i was amazed at the effort it took to move it! Doesn't seem like the servo could work it, but it does.

Anyway, I looked at the tail. All are new parts (from trouble shooting over the corse of I can't remember how many weeks), except the tail shaft brgs. and slider. i can't detect any play in the slider, but changed it anyway. I powered it to hallf throttle and it was STILL real hard to move the rod! So I put 'er back together anyway and gave it a test hover. Wag is still there.

OK... so now I'm fruustrated and pissed as can be and had to put it away before I do something with it that I'll regret. I'm ordering some new tail shaft brgs today and put them in.It still (as I mentioned very early in this thread) has a bunch of vibrations upon spoll up until the full HS (90%) is reached. Don't know if that has anything to do with anything or not.

Thanks again for letting us know you succeeded with your Atom

Chris

[highlightshadow]

Tried spooling up without blades and touching the frame, boom etc to find if it's vibration
I had an odd problem on 450 and by touching boom spooled up I got a real buzz from it so I tracked it down

[Clue!ess]

Maddog, What ever happened with this issue? Inquiring minds want to know....

[kelseh]

Did you ever try replacing your belt. Maybe you stretched it out or messed up a tooth on the belt or your tail pulley.

[maddog57]

Wow, you guys must be physic or something resurrecting this thread now, cuz I JUST got the wag fixed. Here's the story;

Late last fall I joined a RC club but by that time it was too late in the season to fly because of the weather. I was sooooo frustrated with the wag issue that I shelved Atom for the winter.

FF to last week, I got together with one of the club members (Bullitt on the Freak) who has a FB Atom also. After trying a few things, he suggested swapping the tail grip/hub assy's with his heli. Well whadda ya know, no more wag! Last fall I had replaced all parts in the tail except the tail box and shaft brgs. Having lots of spare parts, I put another set of blade grips/hub on after giving Bullitt his back, and my wonderful Atom is back! Took her to the field yesterday and after adjusting in rate mode to get the tail drift free and gyro gain, it flys beautifully!

I've yet to tear apart the bad grip assy. to find the problem, but will and I'll report back on what I find. It's great that you guys care enough to ask about it. It's funny cuz I was planning on bringing this thread back once I figured out what's bad with the assy.

Chris

[Clue!ess]

I love happy endings. Nicely done sir