RunRyder RC
WATCH
 2 pages [ <<    <    ( 1 )     2     NEXT    >> ] 2101 views Post Reply
03-03-2012 09:04 PM  9 years ago
Topic Vote0Post 1
cudaboy_71

rrElite Veteran

sacramento, ca, u.s.

MyPosts All Forum Topic
Furion 450 tail vibes
I'm at a bit of a loss. I've been chasing a bad vibration lately with this helicopter. What's weird is it has slowly come on without warning or incident.

i started diagnosing when the vbar wasn't really performing to par...then, as it got worse was practically unflyable (as it is now). when it was still flyable, i was looking at the vbar live log and i was getting big red flags in the 16Khz range. right about the time of the flight i decided that must be tail related, the heli threw a tail grip as the hub failed (presumably from excessive vibration) and munched itself in the dirt.

so, i've completely rebuilt the tail. new bearings, throroughly inspected. also, the crash induced a complete rebuild of the head..new radial bearings, inspect repack the thrust bearings, new shafts all around.

so, taking a different tack at diagnosing since it can't really fly in its current state, running up the heli to speed without any blades (main or tails) it's smooth as silk.

as soon as i put on tail blades and get the headspeed up it hits a harmonic, and the heli begins a super-high frequency vibration that gets the boom supports going like guitar strings, and of course i can feel and hear the whole heli buzzing.

i've tried 3 sets of tails: hyperion carbons, curtis carbons, and KBB plastic blades. all 3 balanced, and filed down at the root to avoid touching the hub screws (modified and balanced only after out of the bag started vibrating).

i'm stuck. so, any advice or suggestions welcome.
if it ain't broke, break it.
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
03-03-2012 11:05 PM  9 years ago
gorn

rrElite Veteran

Western Australia

MyPosts All Forum Topic
I was right where you are with my Furion.
I balance the whole rotating assembly, and every part was new in the tail, including tail case bearings and belt.

Nothing I did would get this thing to stop vibrating.
I spent months trying to work it out, even had the Oz distributor for MA rebuild the tail himself, just to see if I had missed something.
Short answer, nope.

I will add, when I first got this heli, it didnt vibrate like this.
Crashed it once, and could never get it working again.
If I were into being a masochist, I would buy a new tail case, as thats the only thing I never replaced in my hunt for vibration.

I really liked the way the head flew (flybar), but the tail is a bad joke.

I literally threw it across the room over christmas, and felt damn good for doing so

Now I have an Embla 450 FBL, and am glad the Furion is just another thing cluttering up my garage.

Good luck with yours, I hope you find a solution
For the love of the hobby
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
03-04-2012 02:25 PM  9 years ago
articcat

rrNovice

binghamton new york

MyPosts All Forum Topic
Sounds just like the furion 6!!!! Something to be said about a torque tube....
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
03-04-2012 02:38 PM  9 years ago
Dauste

rrApprentice

ES - UK

MyPosts All Forum Topic
Just use the stock tail blades. A newly built tail will have no vibes if put together properly. Could be that vibes are being induced from elsewhere.

Furion 6 is maybe another issue, I'll get to that on the other thread.
SHARE  PM  EMAIL  Attn:RR  Quote
03-05-2012 03:36 AM  9 years ago
gorn

rrElite Veteran

Western Australia

MyPosts All Forum Topic
when I built mine, it always had stock tail blades, and I tried multiple sets.

The Furion is the only heli I have ever owned that I could not get rid of vibration.
As far as correctly built, I factored that out by also getting the MA distributor to rebuild the whole tail again, it still vibrated.

With or without head on, same.
New main and auto gears multiple times, new tail belt, all new bearings, hubs shafts and even grips.

In the end I decided I was wasting my time on what is meant to be a fun size classs.

It was sure fun when I hurled it across the room
Very satisfying after months of messing around.

I loved the look of the heli, and the head flew like a much larger heli, but the tail is crap, far too much hassle anytime something goes wrong, start chasing vibes again.

I know Im not alone with this issue, besides what Shawn has said in his post as well, I know other that have had the same prob.
For the love of the hobby
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
03-05-2012 04:13 AM  9 years ago
cudaboy_71

rrElite Veteran

sacramento, ca, u.s.

MyPosts All Forum Topic
Not really the news I was hoping to hear...but it does cut to the chase. I may look at modding an align tail to it.if it ain't broke, break it.
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
03-05-2012 07:40 AM  9 years ago
Dauste

rrApprentice

ES - UK

MyPosts All Forum Topic
Are you using the hardened main and tail shafts? If not, try those before you give up. Also make sure you have used new screws for fixing the blade grips to the hub.

Remember there are hundreds of people flying this tail with no problem, it has no design issue and after 4 years is still one of the best flying 450's out there. When set-up correctly the tail is rock solid

Just because someone distributes MA, doesn't mean they are any good at chasing down a vibe!
SHARE  PM  EMAIL  Attn:RR  Quote
03-05-2012 07:47 AM  9 years ago
gorn

rrElite Veteran

Western Australia

MyPosts All Forum Topic
Yes hardened main shaft.
Ive been working with helis as a job for maybe 5 years now, and can build to a high standard.

The only thing I never replaced was the tail case.
Always used new tail grip bearings, spacers, hubs and screws, bearings as well.
For the love of the hobby
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
03-05-2012 07:55 AM  9 years ago
rexxigpilot

rrProfessor

rexxig2@comcast.net

MyPosts All Forum Topic
Check to see if there is slop in the tail by pushing and pulling on the tail shaft.

I had this problem with my Furion 450. I found the cause on mine to be too much slop between the tail case bearings and the tail gear. The blades were rapidly changing pitch (and causing vibration) as the gear slid back and forth as it revolved. The cure is simple and cheap. Remove slop with appropriate thickness shims. Or even simpler, adjust the flanged bearing seating to remove slop. Glue it in new position with medium or thick CA to fill any gap between flange and CF tail case.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
03-05-2012 08:07 AM  9 years ago
gorn

rrElite Veteran

Western Australia

MyPosts All Forum Topic
for mine, I used a shim, no slop.
The vibes in mine were bad enough that it was almost painful to hold the boom in idle 2 (no main blades, with tails, gyro off and blades centered)
For the love of the hobby
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
03-05-2012 08:24 AM  9 years ago
Dauste

rrApprentice

ES - UK

MyPosts All Forum Topic
Well sounds like you were clearly missing something. I've rebuilt the tails on two Furions, maybe 10 times in total and never had a vibe issue (relating to a tail component) afterwards. Check the tail pulley as well as it can get worn down and the belt starts jumping around.
SHARE  PM  EMAIL  Attn:RR  Quote
03-05-2012 08:36 AM  9 years ago
gorn

rrElite Veteran

Western Australia

MyPosts All Forum Topic
That is one thing I never replaced, and it was a 2nd hand machineFor the love of the hobby
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
03-06-2012 01:02 AM  9 years ago
cudaboy_71

rrElite Veteran

sacramento, ca, u.s.

MyPosts All Forum Topic
mine had not been shimmed....though originally it flew fine without. wth...just shimmed out the slop. still resonates something horrible. can it be the belt itself hitting a resonance?

i would say this helicopter has not been crashed, except this vibration apparently caused a bad one that caused the hub to shear off in flight and break/bend the double-flange bearings.

it was flying good for the first 5-10 flights, then it started getting worse and worse, to the point it ate itself.

i've had this tail apart 1/2 dozen times---twice today. everything is smooth and slopless on the bench, and moves very smoothly. once the head hits idleup speeds it's like someone turns on a switch. it sounds like i'm the same boat as gorn. it is actually painful to hold the helicopter when it's resonating.
if it ain't broke, break it.
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
03-06-2012 07:21 AM  9 years ago
Dauste

rrApprentice

ES - UK

MyPosts All Forum Topic
You don't need to mod anything, no need for shims or anything else. If you are confident that the tail is properly built with no bent screws or parts, then I'm sure it is fine. Your issue is somewhere else, just because the tail vibes does not mean that is the source of your problem. I think you should be concentrating on the head end as frustrating yourself with the tail is getting you no where.

Put it aside for a bit and come back to it in a fresh frame of mind. Take things apart and carefully examine the components, if anything is suspect then look at swapping it out. Just randomly swapping out parts in the hope of resolving the issue is not the way to go, you may get the right one, but you will never really know what the root cause was.

Unfortunately we can't fix it for you and without having it in front of us it's impossible to suggest you look at one specific thing. Dampers, shafts, gears, loose screws any of these could be it. Stick with it and I'm sure you can get this licked!
SHARE  PM  EMAIL  Attn:RR  Quote
03-06-2012 10:06 PM  9 years ago
jason46

rrVeteran

MI

MyPosts All Forum Topic
With all due respect, I fail to see how how Gorn's posts are helpful.

Check the mainshaft bearings, if they are shot that would cause a vibe similar to a bent shaft, use to be constant fight on helis with poor quality bearings. Also, if you're running crazy high head speeds might be worth verifying the mainshaft is straight.

I've run the KBB blades without issue and I didn't bother checking the balance. After a tail first crash last fall I recently rebuilt mine with edge tail blades and it is silky smooth.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
03-06-2012 10:30 PM  9 years ago
rexxigpilot

rrProfessor

rexxig2@comcast.net

MyPosts All Forum Topic
cudaboy_71, can you try a different motor? Your motor may have slipped a magnet if it got hot.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
03-06-2012 11:24 PM  9 years ago
gorn

rrElite Veteran

Western Australia

MyPosts All Forum Topic
Jason
All I was adding was that I have been through the exact same thing, and had no joy in getting it resolved.
Not jumping in to be a Troll, or just to be negative.
I was just very disappointed that the problem was not able to be fixed.
No offence taken though, I understand where your coming from.

I will add this as my last comment in this thread so as not to draw it out to much.
My issue as described, same as Cuda, still presented itself with no rotor head fitted.

I had new main shaft bearings,new main shaft, new main and auto gears, new belt etc etc.

Do I still want to know what the cause of the issue is?
Of course I do, but it was involving far to much trouble for me to pursue it anymore.
So I will watch silently to see if Cuda gets a positive result.
For his sake I hope he has a win
For the love of the hobby
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
03-07-2012 02:14 AM  9 years ago
cudaboy_71

rrElite Veteran

sacramento, ca, u.s.

MyPosts All Forum Topic
Dang! I wa hoping horn would fix his first and find the gremlin ;-)if it ain't broke, break it.
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
03-09-2012 05:43 PM  9 years ago
cudaboy_71

rrElite Veteran

sacramento, ca, u.s.

MyPosts All Forum Topic
well, i can say with 100% certainty it is nothing in the furion tail assembly causing the problem.

i just replaced the entire tail with a NIP trex 450 tail. that's tailbox/fin, pitch slider, pitch control lever, grips. only the boom and belt forward remain MA.

same problem.

so, i guess i start working forward. i have NOT replaced the boom or belt yet. guess that's next.

the main shaft is new from the last crash. someone mentioned motor shaft. i guess i can look in there, too.

i have to admit, with the way the vibration was presenting itself i would have bet $$$ that it was tail related.
if it ain't broke, break it.
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
03-09-2012 06:45 PM  9 years ago
Dauste

rrApprentice

ES - UK

MyPosts All Forum Topic
Careful inspection should show you where the suspect part is. No point just changing everything as you go, it will cost a fortune!!
SHARE  PM  EMAIL  Attn:RR  Quote
WATCH
 2 pages [ <<    <    ( 1 )     2     NEXT    >> ] 2101 views Post Reply
Print TOPIC

 7  Topic Subscribe

Monday, July 26 - 1:28 pm - Copyright © 2000-2021 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online