RunRyder RC
WATCH
 2 pages [ <<    <    ( 1 )     2     NEXT    >> ] 1306 views POST REPLY
HomeScale✈️AircraftScale HeliScale Helicopter Main Discussion › epic fail ~ whole lot of shaking going on.
06-05-2011 03:02 AM  8 years ago
Topic Vote0Post 1
SuperSixTwo

rrVeteran

Virginia City, NV ---USA

MyPosts All Forum Topic
epic fail ~ whole lot of shaking going on.
So here it is, my epic fail of today. Not really sure what happened, but there is a whole lot of shaking going on!
It was braced stiff, perhaps to stiff. It is an old fuse with aluminum gear legs and skid tubes.

Thanks Charlie for the video! Great editing with the slomo!

http://vimeo.com/24665902
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
06-05-2011 05:24 AM  8 years ago
hampilot

rrApprentice

Sparks, NV USA

MyPosts All Forum Topic
It was a mean day at Tiger field, Kenny's mustang almost ate me, Paul's heli exploded mid air, Brad needs a nose wheel, and my foamie doesnt like the wind!
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
06-05-2011 07:08 AM  8 years ago
mdm

rrApprentice

PVD

MyPosts All Forum Topic
Incredible to see those parts flex like that in slo-mo. Wouldn't think they could move like that. Cool video.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
06-05-2011 08:27 AM  8 years ago
SuperSixTwo

rrVeteran

Virginia City, NV ---USA

MyPosts All Forum Topic
Yes Charlie, and your black canopy was like camo to! Thankfully pinky has that hot pink stripe to see against the clouds.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
06-05-2011 11:23 AM  8 years ago
FloridaHeli

rrVeteran

jacksonville, florida

MyPosts All Forum Topic
Did you figure out what happened?

It LOOKS Like the tail became unbalanced and came apart. I've had plastic tail grips break and look like this. Never videoed it to see the shaking going on.

Please post the crash analysis so we have a chance to prevent from happening to our helis.

By the way beautiful paint job and finish on the Hughes.
This hobby is WAY too expensive!!
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
06-05-2011 03:51 PM  8 years ago
Mojave

rrElite Veteran

Palos Verdes, Ca. USA

MyPosts All Forum Topic
Wow, great slow-mo vid! It looks like it lost 1 tail blade, shook violently then lost the second blade. You can see the tail blades landing in the background. That's my .02All helis and planes have an expiration date stamped on them...you only find it after you crash!!
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
06-05-2011 06:23 PM  8 years ago
SuperSixTwo

rrVeteran

Virginia City, NV ---USA

MyPosts All Forum Topic
This heli had the tail assy from a 1005 gas MA. For those that don't know them, the tail hub has a rubber dampner kinda like fuel line, and a pin thru the tail shaft. The tail did separate from the shaft, broken at the hole. One blade was broken to, and clearly lands after the heli hits the deck.
The slomo part of the vid, right at 34 seconds, shows the tail fin shaking. It also looks like both blades are still there. At least the "disk" looks there. I think its a resonance thing....

Back to pod and boom for a mechanical vibration study....
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
06-05-2011 11:30 PM  8 years ago
Mojave

rrElite Veteran

Palos Verdes, Ca. USA

MyPosts All Forum Topic
I have watched this vid 20 times trying to see when the crap hits the fan. If the one blade split/broke at the bolt hole, followed by the other, I would venture to say that the out of balance condition just prior to the shake caused the resonance. Given the fact that you were in a resonance free hover when all heck broke loose, that's my best guess.All helis and planes have an expiration date stamped on them...you only find it after you crash!!
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
06-06-2011 02:28 AM  8 years ago
Christopher J

rrElite Veteran

Kansas City, MO Californian lost in land of Oz

MyPosts All Forum Topic
I second that. It looks like all well, the heli is smooth and then the tail gives up the ghost. I've tail failures in the past and what yours did reminds me of mine.Christopher J
same as I ever was
"Still all set & Flying the original"
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
06-06-2011 02:35 AM  8 years ago
Steff Giguere

rrProfessor

St-Eustache, Quebec, Canada

MyPosts All Forum Topic
Hope the damages aren't too big.Team Synergy, Rail blades, Team Scorpion, V-Team
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
06-06-2011 03:31 AM  8 years ago
SuperSixTwo

rrVeteran

Virginia City, NV ---USA

MyPosts All Forum Topic
One of the tail blades broke mid length. Then the whole assy departed stage left...
Damage is easy to fix, i just need to find the AHAH! so i can put it back together without another round of self destruction.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
06-06-2011 03:46 AM  8 years ago
wifeorheli

rrElite Veteran

reno, nevada usa

MyPosts All Forum Topic
Great video and was amazing to see it in person. I still cant believe what happened or what happened spooled up perfectly!! then BAMMM. Well hope to see it again soon(flying that is!)
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
06-06-2011 03:55 AM  8 years ago
Inverted CNC

rrNovice

olympic valley, ca

MyPosts All Forum Topic
At 32/33 seconds you can see the skids tweak way out of line almost a second before the tail starts to show signs of explosion. Whats crazy is those skids have such little mass to get moving like that if it was a resonance from the tail even though the tail is still solid at that point. I'm going with something in the drive train. Is the two stage tranny still intact?

on a positive note....it darn sure sounds like a turbine spooling up!!!!

cant wait to see you guys this weekend at RRR!!
SHARE  PM  EMAIL  Attn:RR  Quote
06-06-2011 06:11 AM  8 years ago
Christopher J

rrElite Veteran

Kansas City, MO Californian lost in land of Oz

MyPosts All Forum Topic
I looked at the vid several more times. I still feel youlhad one heck of a tail failure, but now wonder if it was induced by something in the body. Right about the time the skids flex it looks like something on the mechs went wrong because right about the time the battery can be seen being tossed upwards inside the body flexes, then the boom, then the tail comes apart. Maybe I'm seeing things but that looks too be the sequence. Hopfully the repairs arent too bad and you find your gremlin.Christopher J
same as I ever was
"Still all set & Flying the original"
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
06-06-2011 06:19 AM  8 years ago
seattle_helo

rrKey Veteran

Seattle, WA USA

MyPosts All Forum Topic
Wow- sorry to see this. I think Christopher is on the right track. The skids seem to start shaking before anything else and you can see the innards shifting around quite a bit before the TR fails. Maybe the TR failure was just a symptom of whatever caused the resonance?
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
06-06-2011 04:25 PM  8 years ago
Inverted CNC

rrNovice

olympic valley, ca

MyPosts All Forum Topic
yup, 32/33 seconds the skids get pulled apart by the invisible hand of god and then at 33 second you can see what appears to be the radio tray take a 3 inch vertical leap...then the tail boom gets groovy and finally the tail exists stage left.

The skids are really intriguing. Just look at how much force was applied to deform them like that...literally imagine grabbing them with you hands and pulling them apart how much it would take. Now considering how little mass they have.....that vib must have been off the charts strong to inpart that much force to make them flex like they did.
SHARE  PM  EMAIL  Attn:RR  Quote
06-06-2011 07:03 PM  8 years ago
Christopher J

rrElite Veteran

Kansas City, MO Californian lost in land of Oz

MyPosts All Forum Topic
Inverteted CNC is right, those skids got "wishboned". Suprised you could land on them.Christopher J
same as I ever was
"Still all set & Flying the original"
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
06-07-2011 04:31 AM  8 years ago
Mojave

rrElite Veteran

Palos Verdes, Ca. USA

MyPosts All Forum Topic
I still think that the tail blade caused it. I think what we are all seeing is the airframe reacting to the out of balance condition of the tail rotor disc just before it pukes the blade. If the tail blade split, but was still holding on for a second or two, the tail rotor disc would be out of balance causing that huge resonance through the airframe and it would still appear as though the rotor disc was intact. Then all heck breaks loose. That's my .02, can't wait to hear if he finds some other root cause for the resonance/failure.All helis and planes have an expiration date stamped on them...you only find it after you crash!!
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
06-07-2011 08:02 AM  8 years ago
Inverted CNC

rrNovice

olympic valley, ca

MyPosts All Forum Topic
granted it was a pod and boom 700, but I witnessed a tail grip let go in the middle of a 3D flight. Needless to say it was an instant explosion than bent the boom to the point it struck the blades. the remaining grip stayed intact on the hub and shaft.

From talking to Paul the frame, boom and torque tube are still intact.

From the violence of the vib in the skids and mechanical compartment, my gut still tells me its something inthe drive train with more mass.

Guess we will be conducting a NTSB investigation on the wreckage this weekend at the Reno Fun Fly.
SHARE  PM  EMAIL  Attn:RR  Quote
06-07-2011 05:37 PM  8 years ago
SuperSixTwo

rrVeteran

Virginia City, NV ---USA

MyPosts All Forum Topic
After looking at the airframe i think.....

The torque tube has something to do with it. Maybe its just a freakish length and vibrates, or out of balance, something is going on with it. I did cut 1 inch from it, and replace one of the ends. The bearing is smooth, and not directly in the middle, but if you hold it and spin the tube it feels funny. A vibration type thing.
Perhaps i got to much epoxy down the tube when i reassembled it.

The main mechanincs sit at an angle towards the rear. With the tailboom on, it has to. They also sit tilted to one side, slightly. Again, its a fuse thing. I didnt design it or build in the what floor was there. Without a full cut out down to the glass, i did what i could. Didnt think it would matter. Most helis hovering sit one skid low anyway.

When i mounted the top of the "dog house" to a home made spacer, it was offset. Again this is due to how it sat in the body. I drilled the top mounting hole in the exact center. Then i had to loosen the lower mounting (on the floor) and pull it sideways. This induced some tension in the body. Now it wasnt much. Of a 3mm bolt, it was only off by 1mm, but it did tension the fiberglass.

The tail blades may have hit the mains. Watching the video on a high res monitor at super slo mo, it looks like they flexed up enough to do so. I cant find any damage to the mains, but carbon against plastic tails may not leave much to see.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 2 pages [ <<    <    ( 1 )     2     NEXT    >> ] 1306 views POST REPLY
HomeScale✈️AircraftScale HeliScale Helicopter Main Discussion › epic fail ~ whole lot of shaking going on.
 Print TOPIC  Make Suggestion 

 4  Topic Subscribe

Monday, May 25 - 1:00 pm - Copyright © 2000-2020 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online