550 tail issues [Archive]

istandalone

01-08-2008, 06:34 PM

how many of us h550 owners are having or have had issues with the tail? i'm not too sure what the problem is yet- it just started doing it today but when the head gets to a certain speed there is a horrible flapping (can't really explain it better then that) sound that comes from the tail (i think, can't tell for sure), that will go away when i throttle down. i haven't dared to try throttling up to see if it goes away at a higher hs. i adjusted the belt both ways and no difference. lowering the throttle curve makes it go away, but of course doesn't fix the problem. i've seen bob's vid for fixing the tail for high hs's but with my setup i'm maybe getting 1800 rpm at the most, so i'm wondering if there is a completely different problem. anyone care to guess?

dave26985

01-09-2008, 12:25 AM

Have you checked the belt for any fray's or missing teeth ?

WhirlingBladesOfDeath

01-09-2008, 01:23 AM

Not sure if it's the same thing, but I also get some weird tail action at maybe around 1500-1800 rpm. As it spools up, the tail will kick a few times like the belt is getting hung up on something? As it reaches flying rpm (>2000), it runs smooth as silk. With my original gearing, I was running close to 3000 rpm with no ill effect, but am now running around 2500, and it runs like a champ.

At first I had the belt what I though was relatively loose. I now have it a bit tighter, which didn't make any difference. Next weekend I'll try really loosening up the belt and see if that helps?

ianjh123

01-09-2008, 04:21 AM

This seems to be a common problem. The Hurricane tail resonates (for the unlucky people) at about 1800rpm. Goes away at lower or higher rpm.

I put up with it for quite a while by flying at 2200rpm. I swapped out every tail part with no change. In the end I put a Trex 600 cnc tail on to fix it.

istandalone

01-09-2008, 06:08 AM

i have not checked the belt for damage yet, being that i maybe have 10 minutes of airtime with this. but i'll do that today after work, and see what it looks like. i also ordered from readyH a trex 600 tail shaft/grip/thrust bearing assembly. i did a search and came up with that as the most likely culprit. thanks for the replys, i'll be sure to post back about whether the belt is ok, and if the new parts fix the issue.

Happy|Harry

01-09-2008, 09:20 AM

you could have also tried the gaui thrust bearing tail grips to see if that helped any :)

phil

istandalone

01-09-2008, 12:21 PM

i acutally found a set of trex thrusted tail grips at readyheli for $15, so i got that instead. i didn't think the gaui ones were available, although i didn't even look.

Pinecone

01-09-2008, 01:15 PM

Ready Heli carries them:

http://www.readyheli.com/204720_Thrust_Bearing_Tail_Rotor_System_Gaui_Hurri _p/204720.htm

istandalone

01-09-2008, 01:39 PM

well i guess i should have looked first. on plus of the trex grips though, they are skinnier and i like the look of the align ones better. good to know though if the align's don't fit or work for some reason they have the gaui parts in stock. although i saw an old thread that readyheli says the trex 600's fit nicely.

ianjh123

01-09-2008, 02:55 PM

I tried the Trex thrusted grips also but it didn't cure the problem. Others reported small cracks in the tail case - try a close inspection there.

istandalone

01-09-2008, 03:03 PM

if there are small cracks in my tail case, then they were there from the factory as i've maybe got 10 minutes of flight time on it, and no crashes, no close calls even.
i'm going to have a hard time giving it more throttle when that noise is happening, but if higher headspeed cures it maybe i'll throw my 15t pinion on and hope that the point of "resonance" is about gone.

mjdee14

01-09-2008, 03:39 PM

Has anyone tried a different set of tail blades ? Not Gaui, maybe trex. Just maybe a different shape will not set up the same resonance.....?

istandalone

01-09-2008, 04:53 PM

i've got a set of trex 600 tail blades somewhere in my boneyard, as they got shipped to me by mistake and the store didn't bother to want them back. i'll have to try that, if the root (or whatever it's called) is the same size. also, i know that this is a stupid question and a hard to answer one at that, but how tight are you guys running your tail belts? say if you had your heli resting on it's side and you have a flathead screwdriver resting on the belt with just the weight of the driver on the belt. how close does your belt come to touching? the one complaint i have about the 550 is that it's a ***** to see the belt tension. on my 450 i can just look in between the frames and check, not quite so easy on this bird.

hommer75

01-09-2008, 06:08 PM

Finless said it in his build video; when you shake the tail, you can hear the belt in the boom. That is how tight mine is.

ukgroucho

01-09-2008, 07:06 PM

Has anyone tried a different set of tail blades ? Not Gaui, maybe trex. Just maybe a different shape will not set up the same resonance.....?

I use the K&B 30 size 'stiffies'. They are a little longer than stock but still clear the ground with the stock tail fin.

EDIT: Oh and I use Quick UK Raptor 30 CNC tail grips....

mjdee14

01-09-2008, 10:50 PM

I use the K&B 30 size 'stiffies'. They are a little longer than stock but still clear the ground with the stock tail fin.

EDIT: Oh and I use Quick UK Raptor 30 CNC tail grips....

UK did you have the vibration and resonance they are talking about before using the new tail blades?

What I thought might be that the bigger, smaller, or different style blades might run more smoothly and get rid of the tail vibration....just one thing to try.

it seems some people have had to switch to the trex tail.

That has to tell us it's not in the belt...if they use the same one, maybe the plastic tail flex under certain loads....

I would really like to see someone find the simple fix for this.....or maybe gaui will have to make another change to the kits.

ianjh123

01-10-2008, 01:21 AM

I'd have liked a simple fix! My Hurricane was shaking from new. I first tried Trex tail blades, then Trex tail grips, then Trex tail stays, new gaui gearbox case, new gaui tail shaft. Still shaking!

Only after the Trex cnc tail box did I fix it. Have not tried the Trex plastic case. At least I have a very smooth Hurricane now!

ukgroucho

01-10-2008, 06:17 AM

No... I never flew with the Gaui plastic grips but I did use the Gaui tail blades for a while and they were fine. My move to the K&Bs was driven by two things... more visibility of the tail (I use neon yellow tail blades) and a desire to speed up the piro rate a little. I'm so used to the super fast piro rates that you get on Trex 450s (where I often end up slowing the nose left piro rate) that the 550 seemed slow.

Out of interest, which length tail boom are we taling about here? I use the shorter boom with 500 CF blades.

istandalone

01-10-2008, 09:13 AM

it's the xes with short boom and rcp 515's.

Zoobie

01-13-2008, 11:57 AM

I noticed the little kick every now and then on spool up, but on close inspection, what is actually happening (in my case anyway) is that the entire tail case is pivoting a few degrees around the boom and settling in a new position. In other words it is loose. I will try tighten it up with some tape and see if this eliminates it. This might explain why some people are a) seeing cracks in the case and b) eliminating the problems by using a different case?

istandalone

01-13-2008, 02:04 PM

very good point made. i'll have to try and recreate that issue on the bench, and i'll post back my findings.

woz

01-13-2008, 03:17 PM

Hi Guys I have only recently developed a tail issue. This is my second Hurricane CF with stock set up and have really had NO problems. BTW this is also after 2 crashes .
What is strange after the rebuild, everything was fine, except I noticed the tail case rotate a little. After I repaired this issue , my tail now appears to 'hunt' if I explain it as undercontroll but with out accuracy. I thought it was the gyro, but this resonance sounds like the thing.
also loosened main blade grip tension and tail grip tension. tomorrow we will test !! don't you just love this hobby !

woz

01-13-2008, 04:25 PM

One last thing i think may also play a roll is the boom itself. After my last rebuild, the tail hub didn't sit tightly in the cut out hole.There was alot of play, and the thickness of the aluminium seemed thinner. These pieces came in genuine Gaui parts packets Red/white label.
Just milling this over.
Warren

istandalone

01-13-2008, 07:20 PM

i tried, and could move the tail case very slightly, maybe 1mm of movement if that. i just tightened it as much as i could and it seems to hold now. also put a small drop of thin ca glue between the tailcase and the boom.

rcxm

01-14-2008, 05:10 AM