Duho...stupid tail wag

[maddog57]

Yeah Sly, we PM'd back and forth about this wag problem. In an earlier post here I asked how yours is flying... you must've missed it. Glad you're up and flying. I know I will be soon. I'm working on posting a vid of my wag... stay tuned!

Chris

[sly the dogman]

Humm ! my flying, well average but it will get better I installed a stabilizer on the heli
to help boost confidence.
Minor health issues prevent me from flying as often has I would like but when I do fly its very pleasent & fun.

[allenjames]

Just a thought. Are you perhaps getting static from the belt? Also, do you have the ferite core on the throttle wiring? Check that you have no servo or gyro wires next to the motor wiring.

Hope you get it sorted. I love my Atom as well. It's such an awesome heli.

Cheers

[maddog57]

AllenJames, hi. I haven't, until recently, given too much thought to static as I've read more than once that it doesn't seem to be an issue with the Atom due to it's extra large dia. boom. But I'm seriously thinking of grounding because hey, everything to gain and nothing to lose right?

I do have the ring on my ESC leads to RX. The motor to ESC wires are clear of any other wiring too.

I should have a vid of the wag up by sometime tomorrow guys.

Chris

[skunkworx]

You're right, definitely can't hurt to ground it out, but I don't think that would be the cause. I fly with a single sat on my BeastX and have it mounted right on the side of the tail block with no grounding or sprays on the belt. Never had a static hit or issue (or at least none I've ever noticed). Now on my 6HV, that's another deal. I had a lot of wierd tendencies that lead me to grounding it out and it resolved them all, but none of it affected the tail. Only the cyclics.

Grounding is easy. Just take a self-tapping screw with a loop end on it, drill into the center top or bottom of the boom and then run it up to the boom block bolt or motor mount bolt. The main thing is to have the metal touch the carbon to dissipate it to the rest of the heli.

[xspare]

In my experience, static hits tend to be more of an intermittent twitch or catastrophic failure than a wag. My money is on sly - the Align gyros don't seem to have the best track record - what are the chances that Align gyro got its bell rung during the tip over?

I think I noticed that Spartan Quarks are on sale at half price now.... the world has gone FBL I guess.

http://www.spartanrc.com/store/offer...13&partner=228

Alternatively, do you have another gyro you can swap in or borrow from a buddy?

[maddog57]

OK guyshere it is, sorry it took so long. Please pardon my crappy collective mang. skills. I'm at the top of my driveway on a 40'x40' apron and it's a bit gusty, (that's my story and I'm sticking to it, LOL). Hope you can see the wag.



Chris

edit; don't know why it posted two vids, never posted to utube before. Can't figure how to delete one, sorry

[sly the dogman]

At first the wag looks like the gain is set to high, not saying it is now, just looks like.

[maddog57]

+1...gain is at 68 (DX6i). Lowering gain only slows and "spreads" the wag. 85 is as high as I dare go, which has the wag crankin', above that the heli is almost uncontrolable. Can you hear the pulsing sound that's in sync with the wag?

Chris

[Apples]

@Maddog....

I'm a "hammer and chisel", 67 yr. old guy; my troubleshooting skills ain't that good. I usually rely on "Ah Clem", "The Bum", and "Sly" for advice ... But, the last time my stretched 550 wagged it's tail like in your video, ultimately they were caused by "brown-outs".

Like you, I was using a DX6i and a AR 6200 Rx (don't know if you are using that Rx). The heli would go out in HH, fly, wag, return, and the Futaba GY 401 light would blink, showing that it had rebooted in flight. Soooo, I started changing components... First I changed the gyro to a GY 520. Same results - your wag. Then, I changed to a XPS Rx and my Futaba 9C Tx... Same thing. Then, I realized that the XPS didn't like the low voltage caused by 4 digital servos... so I added a Western-Robotics, 5 AMP HBEC.... That did it... No more tail wag.

I hope the tech oriented posters can jump in here and explain to me what I just wrote.

[maddog57]

Originally Posted by xspare

In my experience, static hits tend to be more of an intermittent twitch or catastrophic failure than a wag. My money is on sly - the Align gyros don't seem to have the best track record - what are the chances that Align gyro got its bell rung during the tip over?

I think I noticed that Spartan Quarks are on sale at half price now.... the world has gone FBL I guess.

http://www.spartanrc.com/store/offer...13&partner=228

Alternatively, do you have another gyro you can swap in or borrow from a buddy?

Thanks for chiming in. I did try a spare GY401 I have and still had the wag. I thought it was good as it worked fine when i had it on my 400 size heli. I have a GY520 NIB that's slated for my 6HV (building, also FB) so I think I'll put that on and see how it goes.

Chris

[maddog57]

Originally Posted by Apples

@Maddog....

I'm a "hammer and chisel", 67 yr. old guy; my troubleshooting skills ain't that good. I usually rely on "Ah Clem", "The Bum", and "Sly" for advice ... But, the last time my stretched 550 wagged it's tail like in your video, ultimately they were caused by "brown-outs".

Like you, I was using a DX6i and a AR 6200 Rx (don't know if you are using that Rx). The heli would go out in HH, fly, wag, return, and the Futaba GY 401 light would blink, showing that it had rebooted in flight. Soooo, I started changing components... First I changed the gyro to a GY 520. Same results - your wag. Then, I changed to a XPS Rx and my Futaba 9C Tx... Same thing. Then, I realized that the XPS didn't like the low voltage caused by 4 digital servos... so I added a Western-Robotics, 5 AMP HBEC.... That did it... No more tail wag.

I hope the tech oriented posters can jump in here and explain to me what I just wrote.

Apples (like that...Apples), thanks for responding. Yes I have an AR6200 RX and am using a CC 10amp BEC. Even tried taking the BEC out of the circut and used the Ice75's internal BEC, which made no difference.

All seems good mechanically. Am starting to think electronics now. So I'll try a brand new GY520 I have and see how that goes.

Chris

[Apples]

@Maddog

While you are checking your electronics, you might try this tool, "The TattleTale, from XtremePowerSystems, or something comparable.



"The TattleTale is a tiny and lightweight device that plugs into a empty receiver channel (or through a Y-cable). This device measures the input voltage and displays the lowest voltage threshold that was captured after being powered on. With a programmable acquisition time of 10ms to 100ms, even the shortest voltage sags can be detected!"

http://www.xtremepowersystems.net/pr...hp?prod=XPS-TT

[skunkworx]

After watching that video, I would definitely say it's not static, nor is the gain being too high. Rather, it looks too low. When it 'hunts' like that, it's a good indication your servo isn't being given enough authority to overcome the wag and it's undercompensating. A faster wag or intermittent wags would indicate too high of gain and erratic, super fast wags means you have a bent shaft, vibration, or something out of balance.

I would suggest chaging your servo ball position. If it's in close to the servo output shaft, try moving it out. The further out you go, the less gyro gain you need.
Similarly but opposite: the futher in you go, the higher the gain in the gyro because you have less mechanical authority or gain.

I have a full-size 8900G on mine and it's set to 16mm or the furthest out position. I tried it at lower spacing and it ended up at like 90% before it held correctly, but that's making the gyro work way too hard. If you have the ball out too far, it will be hard for the gyro to find the correct center position it needs to keep the heading where it wants. It will also wag like crazy on anything higher than probably 60%, if it ever stops wagging at all.

[maddog57]

I think I'll try the GY520 I have , but first I'll try moving the servo arm ball a hole as you've suggested. The only thing I don't get is that it was all fine before the tip over, so unless the gyro took a hit,would moving the ball do anything? Nothing has changed as far as set-up. But hey, I could be wrong. Won't be able to get to it til tomorrow.

Chris

[sly the dogman]

Originally Posted by maddog57

snapped both tail blades and snapped the link ball off of both tail blade grips. Chris

I'd take a close look at those and see if everything is in order
(tailblade grips)

[sly the dogman]

The tail on mine (5.5) wasn't up to par either, could have been stiffer. I changed the wheel on the tail servo and the distance from the center of the servo to the rod. From 13.5 to 7.5, this greatly improved the HH, still has that slight drift but I can live with that (for now).
Now its practicaly hands off hovering.

Hope you get yours resolved soon.

[maddog57]

Originally Posted by sly the dogman

I'd take a close look at those and see if everything is in order
(tailblade grips)

Thanks Sly. All the tail section parts have been replaced except for the tail shaft bearings and the gear box. all seems perfect as far as I can tell.

Chris

[maddog57]

Originally Posted by sly the dogman

The tail on mine (5.5) wasn't up to par either, could have been stiffer. I changed the wheel on the tail servo and the distance from the center of the servo to the rod. From 13.5 to 7.5, this greatly improved the HH, still has that slight drift but I can live with that (for now).
Now its practicaly hands off hovering.

Hope you get yours resolved soon.

Skunkworx suggested moving the servo ball and I was gonna do it, but deceided to try the GY520 first. The ball is also at 13.5mm on mine as it has been since day one. Not sure yet if that measurement will work for the 520, may have to move it one way or the other. I have it mounted, just need to have the time to go thru set-up. I'll let you guys know how it works out.

Chris

[TallPaul]

I think Tim and others are on the right path. You didn't mention changing your tail bearings and I did have one fail. When I held the tail hub and the tail gear box, I could move the tail shaft slight laterally - obviously that wasn't right. When I took it apart, the bearing came apart.

One more item that probably isn't it, my Skookum helps point to the source of my vibrations. I've had more trouble than most with my motor shaft causing vibrations (I test crash my Atom more than most!). You might just get an extra can/motor and see if that helps. If you like the A500, an extra motor won't hurt.