Tail Wag Cures

[mkoutnik]

Originally Posted by tommeke

The thimgs on the end of the pushrod where the bals go in

I think a picture would help...

[tommeke]

this is on the tail servo

[Steve Joblin]

Are you saying that you pushed the ball link past the ball and onto the post between the ball and the servo horn? This would create a "loose" fit that would enable play and slop between the Servo Horn and the Tail Control Rod. I could see how this would eliminate wag, but it would also lead to a mushy tail. In essence, you are saying that the tail wag is due to the tolerances being "too tight" and an "over active" servo. Interesting perspective!

[tommeke]

I experience no slop at all, it's holding rock solid

[conejo]

I tried a lot of things to cure the wag in my 250. Even the Microheli tail. And nothing worked at 100%. Recently I bound the 250 to my DX8 and the tail wag is almost gone. I will change the receiver (AR6100e DSM2) to AR61115 DSMX to get better resolution. Anybody has experienced tail fix when using DX8?

[Harbormaster]

Originally Posted by conejo

Anybody has experienced tail fix when using DX8?

That sounds pretty magical, but whatever works!

[paulrizzo2]

Just flew my 250se for the first time a few min ago. The tail wag was there, but was reduced quite a bit when I turned the gyro gain down. It isn't 100 percent gone however, I see a huge improvement. The little thing hovers rock solid though.

[bigstick]

Read most this post and the last big thing was added a mks ds95i and at almost 100 $ thought it was going to fix. Wrong. As more of what did I have to lose, happen to have a copterX for parts setting around. Took the tail assembly and put it on my T Rex 250 and I'll be sons of a B, wag gone. Flys great. Align should be ashamed of its self to sell such a piece of xxxx. I have 2 trex 600, 700, 550. I'm done with this brand. Keep what I have but for the cost of this 250 you'd think they would pony up and fix the problem. My 2cents worth.

[Beckler]

Originally Posted by bigstick

Keep what I have but for the cost of this 250 you'd think they would pony up and fix the problem. My 2cents worth.

That was my thought exactly when deciding between Trex250/gaui x2. Well I got the X2 and it's super-solid so far, no tail issues. But all machines have their issues. Like the boom support ends on the X2 aren't molded at an angle but rather bent as they're installed--so as a result they break essentially right away! Same thing--wth don't they just fix it!

[bchrny]

I found my problem, as listed on page 7. JRs ds3500g runs at 270hz, having my gyro set on digital is for 275hz or higher. I switched the gyro to analog and the tail is like a weather vane in no wind. Happy Tails

[Harbormaster]

Originally Posted by bchrny

I found my problem, as listed on page 7. JRs ds3500g runs at 270hz, having my gyro set on digital is for 275hz or higher. I switched the gyro to analog and the tail is like a weather vane in no wind.

Huh. I wouldn't think that 5 Hz would be a significant a difference (I really don't think it is), but whatever works!

[mayday1]

Like many of you, I've been struggling with the tail of my 250 (copterX) since day one. I've burnt out
two tail servos (align ds-420 and turnigy ds-480), and killed three kevlar belts in about 450 flights.
I've replaced the tailcase bearings and tailgrip bearings multiple times, added chinese weights
to the grips. After each service, my tail
would behave for one or two flights, and the wag would quickly come back.

This weekend I had 13 flights without any tail wag. I was also able to up my tail gyro gain from 35 to
50 while doing this (I would always get the violent wag of death when the gain went over 40 in the past).
So I suspect my tail problem may finally be fixed.

What changed? I switched to the align belt from the kevlar belt, and I changed the boom from
hobbyking/copterX boom to align boom. My gut feeling is that the align belt made the difference.
It is much softer and more pliable than the kelvar belt. The align tail boom seems heavier and stiffer
than the thin hobbyking boom so perhaps it dampened any tail vibration.

So if you've never tried the align belt, give it a try, it costs only a few bucks.

With the tail locked in, it is now my best flying heli (like the mcpx with a better tail and much more power). My setup: copterX 250se converted to FBL, microbeastx, Hitec hs65mg on cyclic, hs5084 tail
servo, stock align esc and 250sp motor, 15T pinion, plus a 6v sbec, align 205D mainblades, cheapie
hobbyking tailblades, 85% throttle on idle1, 100% on idle2.

[Phil76]

Glad to hear you have found resolution mayday1. Long may it continue

My question though is will it cause any issues if I switch my tail servo (ds420) around so arm end is closer to tail.. this will help me move linkage rod closer to servo pivot. as my gyro is in way. Atm gyro is sitting on 3ft of foam , so I moved it back a little so frame isnt vibrating it...

Having moved arm in from about 6mm to 4.5mm I noticed a difference and was able to up gain to 62% from 58 in dx6i... so i f I can squeeze a bit more in to pivot, then I pray the gain will go up to

Thanks

[mayday1]

Yes, I think you should keep the servo arm at 4-5mm since the 250's tail is very sensitive
to even small servo movement.

I ran my tail servo at 5V and the ds-420 only lasted a couple dozen flights before the motor
went kaput, I don't know if it was a general problem or a one off bad apple, so keep an eye
for any signs of impending failure.

I now have 23 wag-free flights without touching the tail, certainly by far my longest run of
trouble free flying.

[pinguin]

I am not sure about the belt. I use kevlar belt and Align tail boom. No problem on the tail.
I use InoLab 261HB servo.

If I recall correctly, DS420 only has less than 1 kg torque. Better get a higher torque servo.

[JoeW]

Originally Posted by pinguin

I am not sure about the belt. I use kevlar belt and Align tail boom. No problem on the tail.
I use InoLab 261HB servo.

If I recall correctly, DS420 only has less than 1 kg torque. Better get a higher torque servo.

Yes, I think it's about 0.75, the new 425 is up in the 1-1.2 range.

[glarepro]

Having too low of a headspeed can cause tail wag as well.

Thats what happened to me with my first T-REX 450 SE.

I didnt have my Throttle curve high enough to give me the headspeed I need to keep tail authority.

[Rockitglider]

Hello All,

Well I finally have my Align 250 running and flying after much problems with tail wag issues. I got the mechanics of the tail working very smooth from all the advice and videos from HIEM JOINT. I also purchased all the recommended parts for the tail, very good stuff. The problem was that my tail servo would not settle down no matter what I did (DS420 Tail servo). When throttle would increase the tail servo would chatter like crazy and get very hot quickly. I also added some upgrades that will help to smooth things out in other areas, but for me the fix was exspensive but I wanted to go FBL anyways. I put it a DFC head and the Align 3GX Compact FBL controller. It flies very well now, and the only complaint that I have if any is it sounds like the gear drive train may be a little too tight, but it's hard to tell because I've never heard a 250 run before. I fly by myself and don't have a local place to fly heli's, but I am a member of a glider club locally, not sure if anyone knows how 250 helis are supposed to sound. Other than that I very pleased, it was a long time comming to get this heli running, but worth it I think. If someone knows of a way to explain how to tell if the gears are too tight, please chime in and I'll give it a try. Thanks for everyones help with your comments in this thread.

Rockitglider

[mkoutnik]

Originally Posted by Rockitglider

I put it a DFC head and the Align 3GX Compact FBL controller.

How does the 3GX fit on the 250? Where do you have it mounted?

[Rockitglider]

It doesn't fit well. I am looking for a better place for it, I may have to fashion a mount made just for it. I now have it on the bottom of the main frame, so any hard landing doesn't look good for the gyro. I'm going to try to mount it facing down on the factory gyro mount, but it might get alot of vibration from being too close to the frame. I think I might just get some carbon fiber landing skid arms and install some cushion on the gyro to protect it, still out on that one. Any sugestions would be great! Thanks,

Some pics here:
https://www.helifreak.com/showpost.p...&postcount=156

Rockitglider