RunRyder - Carbon Extreme Dampers in Evo Freya Head Problem

rrTV-PHOTO

New HD TV

HOME rrTV-PHOTO GALLERIES MY GALLERY HELP-FAQ

myHOME PM pmRR MEMBERS 530 ONLINE 47 EVENTS SEARCH REGISTER START HERE

2 pages [ << < ( 1 ) 2 NEXT >> ]

2179 views

POST REPLY

Futaba-RC	.	Fast Lad Performance	.	Esprit Model
	.		.

HIROBO X-spec - Freya - Sceadu - Shuttle > Carbon Extreme Dampers in Evo Freya Head Problem

bobc1
Senior Heliman
Location: Southern California

I just sent the following message and photos to Augusto @ Carbon Extreme. Has anyone else had a similar problem?

Hey Augusto:

While installing my third set of your CX dampers (1st two: one in an
XSpec, second in an Evo Freya) in my second new Evo Freya, as I
tightened up the through bolts, the plastic head cracked on both sides.
Check out the photos. I used the "D" dampers with the 75 durometer
oring with no washer/shim as in my other Evo Freya that has functioned
very well. All the dampers & orings were lubed with DOW 111 oring
grease.

Also, re: quality control, the latest $58 damper kit (after tax &
shipping) did not contain the lock nuts for the through bolts. The T
bushings had significant burrs on them. One measured .3965" & the other
.3985". I realized that those measurements are probably within your
limits. BUT...take a look at the photos. Check out the inside ends of
the bushings. One side on each had a significant cut (like from a cut
off tool) that had not been machined smooth. Could the non
perpendicular surface been to blame for the cracked head? Or, did the
bushings allow the orings to be over compressed, cracking the head?

Obviously, I have been well satisfied with my first two sets of your
dampers. What is different about these. If you think the problem lies
with Hirobo quality control on their heads, let me & Jeff G. know.

The part # for the head is 0414-385.

Thanks,
Bob

02-06-2006 Over year old.

Jasper7
Key Veteran
Location: Birmingham , UK

Sorry to see that

But knowing Augusto and Jeff G from the customer service they provide, you should be lucked after.

May of been nice to of given them a chance to investigate, before going public.

Steve

Jasper 7
T-Rex 600N
Sceadu EVO 50
Lisa, the kids & a Morgage

02-06-2006 Over year old.

HOMEPAGE

Gary Steward
Senior Heliman
Location: Steele.Missouri

I`m running the new black dampeners from Hirobo with great results.
I just replaced a yoke that looked like that after a crash.
The crack was in the same place.

Gary Steward

02-06-2006 Over year old.

HOMEPAGE

Augusto
rrAdvertiser
Location: San Diego, CA

Just got the e-mail while checkin e-mails on monday morning.

Replacement dampeners are on the way and please send us those back for inspection.

I don't think it's a dampener issue. As you describe it was done at the time of installation and not while flying.

The dampeners go into the yokes and when installed they don't apply any outwards pressure on them except for the O-Ring. The plastic section only limits the total travel after the O-Ring is compressed. If the ypke broke simply for the O-Ring pressure my guess is that it might have been defective.

Also as posted above I also have seen a couple of yokes broken like that with regular dampeners.

Augusto.

Avant Aurora Ultimate

02-06-2006 Over year old.

bobc1
Senior Heliman
Location: Southern California

Jasper:

The problem occurred. My post is meant as an enquiry to see if anyone else has had a similar situation and possible solution.

If you read my message to Augusto, I made it clear that I have been a fan of his products.

My post is not meant to belittle a product, just investigate the issue/solution.

Bob

02-06-2006 Over year old.

tchavei
rrProfessor
Location: Portugal

I saw in a website somewhere that the CX Freya dampneres were only recommended when using a metal Yoke... I whish I could remember the site but I googled so many searching for dampneres for my Evo 50 + Freya...

Anyway, I'm sure Augusto would have brought this up if this were true.

Tony

--------------------
"Perfection and patience usually walk side by side..."

02-06-2006 Over year old.

HOMEPAGE

bobc1
Senior Heliman
Location: Southern California

I sent a PM to Jeff G. for his opinion.

Augusto:

Are the dimensions of the T bushings correct?

I agree that the outward pressure of the oring probably cracked the head. If the bushings are too short, couldn't the oring be over compressed?

Your dampers in my other Evo Freya have worked flawlessly.

Thanks,
Bob

02-06-2006 Over year old.

Augusto
rrAdvertiser
Location: San Diego, CA

No the pressure from the compressed O-Rings should have never broken the yoke. In flight the forces applied to the yoke are orders of magnitude larger than that.

Augusto.

Avant Aurora Ultimate

02-06-2006 Over year old.

Super Phreek
Veteran
Location: Sunny Lancaster, California

What was the outcome concerning this issue?

Were the bushings incorrectly machined? If they were, what would be the correct size??

Derek

If you're not flying low; you're not flying

02-12-2006 Over year old.

bobc1
Senior Heliman
Location: Southern California

Super:

Augusto advises that his factory is finishing a batch & will ship them to me this week.

I will report back re: dimensions.

Bob

02-13-2006 Over year old.

d3sbo
Senior Heliman
Location: cambridge uk

mine has done it to

02-15-2006 Over year old.

Scooterpilot
Key Veteran
Location: Southern, California

I see someone else has had an issue while installing the CX dampners!

Has anyone provided the spec's for the dampners to BobC1 yet? So he can compare it to the ones he has now has! It's been 10 days and no spec's have been provided to him.

What are the dimension for the parts within the CX kit? Anyone?

BTW, Augusto has a good product and I've bought parts and been very satisified with the product.

I too am very interested in the dimensions of the CX dampers for the Evo.

Regards,

Scooterpilot

Two N-9's,600N, MagnumFuel Rep, YS Rep

02-17-2006 Over year old.

bobc1
Senior Heliman
Location: Southern California

Ten days later & still waiting. The following has been my PM correspondence with Augusto.

If the ones at the factory were OK, why weren't they sent?

Maybe I'm missing something.

Jeff G. already sent another replacement head, although I'm uncertain that the original one was defective.

Those acceptable dimensions for the bushings and hard plastic inserts seem to be very evasive.

I'm trying to be objective but I think I'm getting the idiot treatment.

Also, it appears that another person from the UK suffered a similar problem.

If it's a real problem, how about solve it & move on, Mr. Vice-President?

Am I on ignore?

Re: CX Damper Problem in Evo Freya Head

What's the length of the bushings & hard plastic damper inserts supposed to be?

Quote
--------------------------------------------------------------------------------

Augusto wrote on 02-11-2006 09:21 PM:
Hi bobc1

They checked the ones at the factory and didn't find them with that problem. I placed the request to send you one and they are finishing a new batch that will ship this coming week.
Please send those back to us so I can take a look at them.

Regards,

Augusto.

Avant FX & Avant EFX

Quote
--------------------------------------------------------------------------------

bobc1 wrote on 02-11-2006 06:40 PM:
Hi Augusto

What have you found out?

Thanks,
Bob Campbell

Quote
--------------------------------------------------------------------------------

Augusto wrote on 02-06-2006 09:31 AM:
Hi bobc1

Why didn't you let me talk to the factory and find out about this problem before going and posting it all on the net?
It's only Monday morning and I'm just checking my e-mails.

I'll check on it and lt you know.

Augusto.

Avant FX & Avant EFX

Quote
--------------------------------------------------------------------------------

bobc1 wrote on 02-06-2006 09:21 AM:
Hi Augusto:

Please check out my post at:

http://www.runryder.com/helicopter/t233296p1/

Thanks,

Bob Campbell

02-17-2006 Over year old.

Augusto
rrAdvertiser
Location: San Diego, CA

This is an issue with the hirobo yoke. I got a few PMs from people that have broken them using the stock dampeners and were not using the CX dampeners at all. You didn't even fly it when they broke just installing them under no flight loads whatsoever.

If it makes you feel at ease please return the unit or units and we will refund your money for the dampeners so you don't run the risk of breaking your new yoke using our products. We simply don't want to get blamed for a defective plastic design issue. There are hundreds of people out there using the exact same dampeners in their EVO-90 yokes without any problems. There are defective yokes that will simply break using stock or CX dampeners.

I'm on my way to the Vegas funfly so I won't be able to respond to your replys until tuesday. I will PM you a way to contact me on the phone so that if you need to discuss this while I'm at Vegas you can do so.

Augusto.

Avant Aurora Ultimate

02-17-2006 Over year old.

RobRoy
Key Veteran
Location: Huntsville, Alabama

Just out of curiosity Agusto, bobc asked for the acceptable dimensions for the bushings and hard plastic inserts, I too would like to know this. These numbers would go a long way to proving exactly who, or what part was the problem here. If it's not your part that's the problem, then what do you have to lose? If it is, your handling of this is suspect to say the least. I believe in the inicent until proven guilty concept, but if you have an airtight alibi, then why not use it.

.

Ignorance is curable, stupidity is for life.

02-17-2006 Over year old.

Augusto
rrAdvertiser
Location: San Diego, CA

I simply don't have the dimensions right now. I passed his dimensions along and they took care of it. The issue is that it doesn't matter what the dimensions the dampeners are they simply won't compress to the point of breaking a yoke. The whole concept of the V2 dampeners is precisely that they don't compress so that you can have nice autoing. The hard dampener section slides in without much friction and they simply start getting in contact with the yoke after some deflection of the yoke happens in flight. The only thing putting a slight pressure on the yoke at the installation time is the o-ring not the hard plastic. They only contact the yoke during deflections. That's why I simply don't want to get into arguments until I get to inspect the units but despite all that the problem happens with yokes using stock rubber dampeners.

cya all in Vegas.

Augusto.

Avant Aurora Ultimate

02-17-2006 Over year old.

u.k. sailor
Veteran
Location: cambs uk

hi I don't want to get flamed here but please lets have a bit of calm and logic here. I am sorry anybody has a problem of any sort with their heli, but would like to remind people that Jeff Green has a legendary reputation for product support.
I recently had part of my EVO 50 plastic tail break off in cold weather, still love the heli though.
I also recently purchased an EVO 90 and avant conversion but only after finding Augusto to be fast to respond with help and answers to questions and found him to be very up front and straight with me, so I had and still have confidence in both him and his products.
That there is an issue here is clear but if there have been problems with this head and the stock dampners then it is more likely that there may be a problem with some of the heads, whether by design, fulty manufacture or plastic, but the reason may not be quick to find.
Personaly I am paranoid and prefer a metal head on the 90's but even they are known to fail in flight on some machines.
I am happy that the failure showed up without the loss of a machine and hope you are back in the air soon.

02-17-2006 Over year old.

d3sbo
Senior Heliman
Location: cambridge uk

hi all

i hope this will fix the problem

[url=http://www.ronlund.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=heli&Product_Code=414410]

mine is on tis way along with
404817 - STABILIZER CONTROL ARM SSR-V
414413 - COUNTER GEAR EX 18T
414229 - FREYA METAL AUTO HUB
2500102 - ONE WAY BEARING 12 X 16L EWC
2500047 - BEARING 12 X 21 X 5
404730 - RADIUS BLOCK BLUE CNC
404731 - SLIDE BLOCK BLUE CNC
404683 - EX WASHOUT CONTROL ARM

i know your going to say i should off got the CX head but i dont want to wait

02-17-2006 Over year old.

bobc1
Senior Heliman
Location: Southern California

The cause could certainly be the orings being overcompressed. I agree 100% with Augusto that the hard plastic bearings are a sliding fit both around the T Bushings and into the plastic head dampers bosses. However:

If the T Bushings were too short or if the hard plastic dampers were too long, it would over compress the orings & force the head bosses outward.

If you calculate the forces involved, just 5 ft lbs (60 in lbs) of torque on the 4mm (.7mm thread pitch) through bolts would produce 13,000 to 14,000 lbs of force/thrust on the bushings against the orings (if the dimensions were incorrect). The surface area of the orings is less than .5 square inches. This could produce over 27,000 PSI which is probably more that the plastic head could take.

This seems to have deteriorated into a P***ing match when my intent was to resolve the problem & move on. Obviously, I have been completely satisfied with the CX damper systems in the past to have purchased a third set.

The features that I like about the CX system is their longevity & the through bolt/lock nut system to avoid having to fight with locktite removal to install new dampers.

Jeff G. advises that the newest Hirobo dampers last 20 gallons with no problems. Now that I have drilled out my center hub to accept the CX dampers, I suppose I could use the Hirobo dampers with a through bolt system, in the worst scenario.

On the plus side, Augusto had his factory send me another set of dampers, last night after my post. I will be able to compare these to the ones that cracked the head.

He was also nice enough to provide a phone number to discuss the issue which I plan to utilize.

I assisted with the assembly of an Avant from CX several months ago & was very impressed with the quality and detail of the engineering & machine work. I did not begin this thread as a CX bashing forum.

02-17-2006 Over year old.

Davo
Veteran
Location: London, UK

I think I understand your concerns i.e. that the bushings were too short and this meant the o-rings were overcompressed leading to excessive radial force, but I don't quite follow your derivation of the pressure exerted on the head. Think you need to check the numbers/ mechanics.

02-17-2006 Over year old.

2 pages [ << < ( 1 ) 2 NEXT >> ]

2179 views

POST REPLY

Thunder Power RC	.	Real Raptors	.	Mikado Modellhubschrauber
	.		.

HIROBO X-spec - Freya - Sceadu - Shuttle > Carbon Extreme Dampers in Evo Freya Head Problem

UPDATE SCREEN PRINT TOPIC

Advertisers

Subscribe to This Topic