"OH NO" I have the "WAG"

[mjdee14]

Well...I have finally developed the dreaded WAG everyone has been talking about....

Until you see it....you really don't understand it....it is definately not the gyro hunting..

Is everyone else also hearing the gear wine that accompanies the wag?

As you spoll up it comes up nice and smooth then when the rpms catch up "Wham" you hear a funny gear noise and the wag starts...spool a little higer and load the gears and the noise and wag go away till the rpms stabilize and the noise and wag start again.....I also have the thrusted tail bearings

Is everyone else getting the noise ?

Sound like th gear train loading and unloading either causing the tail rpm to fluctuate or something...

Has enyone else found a definate fix? Did the metal gearbox always cause it to go away? i wouldn't think so given the noise and problem I hear...

Well i'll start to investigate and will report on any findings.....

never really understood it until I saw it......I already tightend the belt...made no difference at all.

Also went to get a few flights in and only took 4 sets of lipos TX, and heli....after the first flight the nose/tail was drifting so I went to make an adjustment to the tail rod and "BROKE" the servo arm !!:mad: All spare parts at home.....well that was a wast of 10 miles of driving to a field....:arggg::arggg::arggg:

Hope everyone else had a beter day of flying than I did...

*** UPDATE, GOT RID OF THE WAG **** see post #11

[Wazzer]

Man what a bummer

Its like when you havent flown all week got itchy fingers and then when saturday morning comes round you load the car get to the field mount your batteries preflight checks spool her up lift off into a nice stable hover then the wind picks up and the rain starts!

2 mins of flight in a week is NOT enough!!

Guess what happend to me last week!

Ben

[bearwood]

I am trying to sort this wag out as my flying level is Hover only and it is very disconcerting having the tail wag. I am very reluctant to let the Heli go more than 45 degrees to me and then have it wag. This is a distraction that I don't relly need right now.

Anyway I have fitted a complete metal tail http://www.takeoffandland.com.au/product_info.php?cPath=131_139&products_id=2584&osCsid=a698292afcd000f28a51ed63d8e301d0 and so far it is looking good. I used to get Wag everyflight but only in the first few minutes of the flight. I have run 3 packs through and so far no wag. I hope to get a few more packs through today, wx permitting so I will report back.

Can't say I have noticed a noise but I upgraded to a Z20-1470 which has changed the noises a bit.

[Cralis]

Mike, I'm assuming you have your heli setup that you can hold a hover in non heading hold mode? Mines swining a lot so I need to sort that out. I'm wondering if it's related? Also, have you tried a headspeed increase? Tail blades maybe a bit too loose?

[xfaega]

bearwood, How do you like the cnc tail? I wanted to know the quality of the cnc. I have been looking for a good upgrade but haven't heard much of the helidirect cnc tail that you bought. So let us know how you like it. Also for the tail wag have all of you checked the belt to make sure it is not to loose? I have the same problem and tighten the belt slightly and the wag went away. I also had to increase the tail blade pitch to the left by two turns on the link hook.

[bearwood]

OK I got 3 packs flown/hovered this afternoon and the wag is still there. I tried adding more delay from the gyro and made no difference.

I think it is now more pertinent to collect some setup data from those that have the WAG and those that don't. I can only hope that this points to a common element.

I have a CNC tail a GY401 gyro and a no name brand tail servo.There is 5mm of belt deflection measured from the rear of the triangular hole from either side of the frame. The hover is stable in non-heading hold. I am using a Z20-1470 with a 14tooth pinion and a 61 tooth front gear, my throtle curve is quite low, point 3 is at 60% DX7

xfaega
I am impressed with the quality of the CNC tail that I have. It is very smooth and the screws I checked had locktite so I did not disassembled the whole thing. It is a Sonix brand. The boom clamp is nice and tight, much better than the Gaui plastic tail. It uses the Gaui tail shaft and pulley.
If the Helidirect CNC rotor head is anything like the tail I would be very interested in it, when I come to need one. I assume the Helidirect tail is a sonix unit as it looks very much the same.

[mjdee14]

I have tried tightening the belt...

When out flying to day..the heli was drifting to the left...so I landed and tried to make some ajustments in non -HH... broke the servo arm :arggg: left my ball link pliers home...

Came home and swapped arm...while trying to adjust the wag started....

NOW, I also switched from the Gaui 50 amp to the Align 75 amp ESC just before today...the noise I heard was like it was winding up OK then when it got to where the rpms match the stick it would wag, increase a little more it would go away till it evened out and it would wag again....sounded like the gears were unloading, so maybe my problem is the ESC pulsating.


Bearwood....when you say stable in non-hh you still have the Wag correct? you just mean it's not drifting, but it's still wagging?

I have a new in the box CF frame so I swapped out the OWB and main and primary gears.... Hopefully I'll try it tomorrow and see if it makes any difference.....if not I'll swap back to the Gaui ESC did not have this problem before today...

I'll report back any findings...

[bearwood]

The ESC is an interesting thing as I too have fitted new ESC (Hobbywing clone). I don't remember the wag beforehand now that I think about it.

[bbagle1]

I had the wag. Pissed me off pretty good for a couple of weeks. I Have the CF frame. Went through every bolt on the frame, loosened, re-loctited, and snugged. Not tight at all. Just snug. Also make sure the belt tension is just right, it should push in 6mm when you check the tension of the belt near the tail pully. These two things eliminated the shake/wag. I didn't have any gear noise.

[istandalone]

i do believe that this "mystery wag" is belt related. the belt has to be just perfect tension.

[mjdee14]

OK the WAG is gone !!! :thumbup:

Not sure exactly what did it but let me tell you what i did....

1. changed the OWb, main and first gear with new parts. ....No Help

2. tried all different settings on the Align 75 a....gov...non-gov....med, fast, and low start...
all...No Help .

3. Swapped back to the Gaui 50 amp and thought it was better...tried all settings but still had the wag, just not as bad...so I'll say ....No Help.

Since several have said they got rid of it with a CNC tail...I figured that was a good place to start.

1. I split the tail case on the shaft after removing the holders, slider and hub assembly.

2. I ensured the belt was not twisted in the tail.

3. I found the slider bearing to be a little rough....I back off the bushing 1/8 or so of a turn and it worked much smoother.

4. I found evidence that the tail control arm was rubbing a little on the bottom of the tail case..maybe more at high RPM's( but I don't know for sure) I put a small washer under the arm and it moved it out and gave some clearance.

5. I was running thrusted tail holders and they seemed dry..I lubbed them and also changed the position from next to the hub, to out by the bolt head. The holders seemed tighter than before but moved very freely.

I also took this oportunity to check the slider arm pins....they were loose as anything and could be EASILY punched out....put a drop of CA on one end of the pin and on both sides of the arm.....hit it with accelerator, it's not going anywhere now.

6. lastly, tightenend the belt more than before....just a few mm of travel.



Took it outside for a test and it spooled up Smoothly, and never got a wag. had to readjust the nuetral hover in non-HH since I moved everything around.

hoverd through a whole pack and spooled up and down at least 10 times without even
a hint of a wag.....

So, what fixed it :thinking Your guess is as good as mine,

I think some binding along with the belt tension, maybe even the ESC...the only way I will be able to tell that is to re-install the Align ESC. Since I'm running the Z20 I really don't need it right now as the gaui is running great. So I'm going to leave well enough alone...and since many with the Wag are running Gaui, I doubt it was that, but I'll try it some day.


I'm happy with it and now I can relax and enjoy the Heli again.....because that was really a pain in the arse.

Mike D

[xfaega]

"4. I found evidence that the tail control arm was rubbing a little on the bottom of the tail case..maybe more at high RPM's( but I don't know for sure) I put a small washer under the arm and it moved it out and gave some clearance."

I found this to be a problem also but didn't really think that would cause the wag until after flying. I also includes extra washer to get more clearance and that made a big difference also the tail servo had to work less (no buzzing while on the ground).

All of the others things that you found could have or could be others problem with the wag.

Thanks for sharing your finds and fixes.

[Wazzer]

Great info Mike

I dont have the wag but i will go through your list anyway as some of those are good points to look for.

Thanks for sharing

Ben

[istandalone]

try tightening the piss out of the belt. it's possible that your belt hasn't broken in yet and needs to stretch. all of my tail vib seemed to center around belt tension, and you've got to have it just so. pita for sure.

[mjdee14]

try tightening the piss out of the belt. it's possible that your belt hasn't broken in yet and needs to stretch. all of my tail vib seemed to center around belt tension, and you've got to have it just so. pita for sure.

I definately tightened the belt much more than before...and that may have been the problem....it was good to rectify the other small problems I found also...

It runs great now... i just need to try the Align 75a again and see if that works as good or better than the Gaui 50a

[xfaega]

mjdee14
Let me know how you have your Align 75A setup. I keep getting the cutting in and out at 1/4 thr. I am running 2 3s1p TP 2100mAh prolites and the Tonic-X Z20A with 14T pinion and 42T front gear and 61T back gear. I started after I installed the Tonic-X Z20A. Before I had a no name BL motor which ran hot with only a minute run time. Here is my Align 75A beeps 1B 3B 3B 3B 3B.

[mjdee14]

mjdee14
Let me know how you have your Align 75A setup. I keep getting the cutting in and out at 1/4 thr. I am running 2 3s1p TP 2100mAh prolites and the Tonic-X Z20A with 14T pinion and 42T front gear and 61T back gear. I started after I installed the Tonic-X Z20A. Before I had a no name BL motor which ran hot with only a minute run time. Here is my Align 75A beeps 1B 3B 3B 3B 3B.

When you say "cutting in and out" is headspeed coming down or is the tail wagging and you hear the gear noiose like it's unwinding?

I had it set up the same way except on the last I used medium speed...it did not cut out on me at all, but I did get the wag after installing the Align...it may have just been a coincidence.

Several have said the Align does not work good with the Z power motrs....(Tonic)..

I wonder why?



Anyone else out ther using the Align with a Z power and not having problems.?

Do you have an Eagle tree or some way to check and see whatis going on at the point of cutout?

I wonder if Align would be any help?

[X30PILOT]

xfaega,

You have your ESC set to governor mode. At low power settings it may be confused as what you are trying to do. I have the same ESC set to 1-3-2-2-3 and it works well with my Z20-980, I no issues at all.

X30

[xfaega]

mjdee14 - what I meant was the motor cuts out the starts again.

X30PILOT - I will try your setting. I just followed finless video he had on how to setup the Align 75A. Couldn't find anything else.

Thanks
XFaega

[bearwood]

I have managed to get rid of my wag as well. :banana
I changed back to the Gaui 50A esc and tightened the belt, not much but it is tighter.
Ran 2 packs thru it hovering, no wag.
But what fixed it? the esc or the belt?
So I changed the Esc back to the EMGC-60A as I didn't want to disturb the belt if it was in the "magical tension range".
Ran another pack thru and still no wag, so it looks like the belt tension is fairly critical as a number of people have already stated.

mjdee14, I will be most interested to hear what happens when you fit the Aligh esc.

If it proves to be the belt tension how can the tension be repeated?
A measurement of deflection of the belt is fairly meaningless as the amount of resistance from the belt will vary from person to person. If I shake the tail hard I can hear a slight "tink" as the belt hits the boom.

[Madedon]

I have managed to get rid of my wag as well. :banana
If it proves to be the belt tension how can the tension be repeated?
A measurement of deflection of the belt is fairly meaningless as the amount of resistance from the belt will vary from person to person.

I have this wag in my hurricane as well and after trying a number of different things which didn't help I believe the cause is the tension of the belt. (I have install the cnc tail upgrade recently)

For all of you that you get rid of the wag is there any way to share how much is this magical tension on the belt. Possibly a photo or even a measurement with a specific weight on the belt would help.

[bearwood]

My belt tension is: using a 2mm allen key, I get 4mm till the belt goes really tight (can't push much harder with 2 finger grip). This measurement is at the rear of the triangle on the left side.
Thats about the best I can give as I have no way of measuring the amount of force required

[mjdee14]

.

If it proves to be the belt tension how can the tension be repeated?
A measurement of deflection of the belt is fairly meaningless as the amount of resistance from the belt will vary from person to person. If I shake the tail hard I can hear a slight "tink" as the belt hits the boom.

On spool down I also heard a "tink" as the blades came to a stop..the belt felt tight but I tightenend the heck out of it....

I am really surprised that the belt would cause the wag I felt, BUT I guess having that long a run in the boom and the air load on the tail blades must cause the pulsation or momentory loss of power. My Eagle tree doesn't show any significant change in rpm's.

Maybe all the wags can be fixed with a belt adjustment. Hope that's all it is.

[Zoobie]

I have often thought about ways of standardzing belt tension. In full sized machines they have a little gadget which reads pounds/kilograms per square inch/cm. We use a similar thing in medical research to assess pain tolerance (dont ask!!), but they are quite pricey. I thought of using one of those little trout fishing scales and hooking it around the belt at a specific point and then measuring the "weight" it takes to just get the belt to touch. Anyone got any similar ideas?

[bearwood]

Zoobie,
On real aircraft we use cable tensioners which hang on the cable and then push the cable and measure the deflection which as you correctly state is measured in lb/sqin. They are normally used in the middle of a cable run.
The fish scale may work but it would have to be for really small fish (my scales don't read below 5kg and its not worth fishing for anything less;) ). But seriously the scale may work using some nylon fishing line to loop around the far belt and pull it towards the near belt. The main problem I see is that we would be measuring the belt very close to the pulley and should ideally be measuring it half way down the boom which is obviously not possible.
Perhaps as mjdee14 says the belt has to be tight due to the length and the stretch/play in the belt when it is running. Maybe it was going into resonance.
My "Wags" were happening often, like every 3-4 secs. The tail kicked quickly to the right about 10-15cm. Almost as if the belt had skipped a tooth, then it would return to original position just as quickly. The tail would make a noise almost like a bark as the blades gripped the air.
As a side note my headspeed is quite low due to my flying abilities at the moment. I am slowly increasing the throttle curve as my confidence increases.