Anyone actually seen wood blades explode?

[rfequity1]

I read on here not to run them over 2000 rpm. On the Trex 450 those blades turn at close to 3000 if I'm not mistaken, and I use woodies on that heli. All sorts of wood blades are made for 50 size helis. What would cause them to explode at high rpm? As far as I know wood is a very strong material. Just looking for some in depth understanding, not stuff we've heard from someone.

[invertmast]

i've had a brand new pair split lengthwise and chord wise. first flight on them. was in hover w/ about 1600rpm headspeed breakin in a new engine. heard the covering flutter next thing i know i hear a thunk sound and then a thud and the heli doing a chicken dance on the ground. hit TH, and put the trans down and then the engine died. One half of the blade (broke chord wise) had hit the trash can that was 18" to my left of where i was standing. go to the heli and the only thing left was the main mechanics, the boom was gone, along w/ the tank, skids, canopy and the other blade was split root to tip length wise. I did epoxy the grips to the wood blades w/o the covering. So i NEVER use wood blades again after that. after 2 hours of searching i found the boom about 60 yards away, the canopy was hanging in a tree w/ the skids and the fuel tank i never found.

[mile hi flyer]

I had a set of TT wood blades on my Raptor that failed when I was a newbie to the hobby. The head speed was around 1800 and one blade came apart at the root. It is definitely not a pretty sight. It sounded like a shotgun went off and the heli was completely destroyed. The blade went about 100 yards behind me. Very scary. Haven't used wood blades since.
Troy

[frogbmth]

Like this?

http://www.youtube.com/watch?v=UnQ5Qnovzdg

[invertmast]

Like this?

http://www.youtube.com/watch?v=UnQ5Qnovzdg

there's a very good reason for that one.. no pitch and all power = not too good for woodies.

[frogbmth]

I've been running the Align woodies on my 450 for a while, no problems at all, and a guy at my club flies his Rappy 60 3D style with woodies! I'm on carbons with my 600N, these days you can get good carbons for little more money than woodies.

[Pinecone]

There is a thread here on the forces. Shorter lighter blades are a LOT less stress at the same RPM.

[rfequity1]

I appreciate the responses. I ordered a set of Align GF 600d from Heliproz. Hope that the right choice.

[MXRACERX43]

Did you remove the covering around the root and soak the area with ca or coat with epoxy? I do agree thought why trust a $1000 heli on cheap wood blades?

[rfequity1]

I did epoxy them and they have been fine for hovering, however, I'm nervous enough trying to fly, so I don't want to worry about this on top of it all. I ordered some better blades.

[fiveoboy01]

there's a very good reason for that one.. no pitch and all power = not too good for woodies.

Exactly, something didn't sound right with that thing.

[jaywhy]

there's a very good reason for that one.. no pitch and all power = not too good for woodies.

That video is awesome.

So, that is reproducible ? :)

[invertmast]

That video is awesome.

So, that is reproducible ? :)

yes. i could make any heli do that w/ Zero degree's of pitch and 100% power

[frogbmth]

T-Rex suicide? :lol:

[invertmast]

T-Rex suicide? :lol:

LMAO.....

[Forced_Induction]

i believe that the graph i saw showed 600mm blades at 2000rpm would give a centrifugal force on the grips of 800lbs pulling out. not sure what weight the blades were though, but thats insane.

[invertmast]

i believe that the graph i saw showed 600mm blades at 2000rpm would give a centrifugal force on the grips of 800lbs pulling out. not sure what weight the blades were though, but thats insane.

now take a 325mm blade that weighs 67 grams i believe, and see what kind of weight that pulls at about 4500rpm, b/c thats what the headspeed sounded like to me in that one video on youtube..

[Forced_Induction]

by the looks of that video, there will me more force than woodies can handle :)