Lightened flywheel gone wrong.

[Flyin4stroke]

to limit the chance of an alternator fan to the head.

I hate when that happens..

[AlaskaFestivaGuy]

Advanceddynamix,

I like the term "scatter box!"

Here's a good one I remember.

http://articles.latimes.com/1985-04-17/local/me-14658_1_engine

Unless they've found it, there should still be an approx 10,000-pound 727 engine self-buried in the NM desert. Aircraft obviously didn't have GPS back in 1985 (much of the "should be recycled into paper clips" garbage legacy operators are flying around still don't), and high-altitude radar isn't all that accurate, so it may never be found.

[Advancedynamix]

Some years back, I read about a case in California where the stock generator pulley on a VW Bug fractured while driving down El Camino Real (aka "Main Street"). A piece of the pulley shot out through the body and flew into the head of a kid on the sidewalk, killing him instantly. Apparently, the pulley had a manufacturing defect in the form of a hairline crack.

There have been several case of jet engines discombobulating on takeoff, with rotating parts piercing the containment vessel, which I think is made out of titanium, then penetrating the fuselage and impaling passengers. FAA requires testing wherein a single fan blade is intentionally separated at its root (using remote-controlled explosives) at high rpm to see what happens. The containment vessel is supposed (and usually does) keep everything inside. The resulting out-of-balance condition, however, sometimes causes the engine to separate from the wing/fuselage. The engine mounting points are designed to fail under massive loads rather than let the distressed engine bring down the entire aircraft.

I've noticed that some newer 737-800s lack windows at seats 9A and 10F for no apparent reason. I suspect it's because there's a metal plate in place of the window to stop flying bits of engine. Personally, I won't sit in those rows.

Lol! I make the scatter boxes (testing fixture) that Honewell tests their engines in so I can verify this.

Also, I bought a VW Jetta gli from a close friend and it had a big tear in the hood right over the alternator. The alternator fan had separated and it flung right out of the hood, scared the crap out of him. He took it as a sign to sell the car. lol.
Modern alternators have internal fans (like the alternators on our festivas) to limit the chance of an alternator fan to the head.

[AlaskaFestivaGuy]

Some years back, I read about a case in California where the stock generator pulley on a VW Bug fractured while driving down El Camino Real (aka "Main Street"). A piece of the pulley shot out through the body and flew into the head of a kid on the sidewalk, killing him instantly. Apparently, the pulley had a manufacturing defect in the form of a hairline crack.

There have been several case of jet engines discombobulating on takeoff, with rotating parts piercing the containment vessel, which I think is made out of titanium, then penetrating the fuselage and impaling passengers. FAA requires testing wherein a single fan blade is intentionally separated at its root (using remote-controlled explosives) at high rpm to see what happens. The containment vessel is supposed (and usually does) keep everything inside. The resulting out-of-balance condition, however, sometimes causes the engine to separate from the wing/fuselage. The engine mounting points are designed to fail under massive loads rather than let the distressed engine bring down the entire aircraft.

I've noticed that some newer 737-800s lack windows at seats 9A and 10F for no apparent reason. I suspect it's because there's a metal plate in place of the window to stop flying bits of engine. Personally, I won't sit in those rows.

[SiC sEnSe]

thats awesome now to make sure its put in properly

[eurotiva]

I had one come off of my lathe. It was crazy. That looks like a festy but something says its not.

[Ford Fester]

http://www.youtube.com/watch?v=w-2Ki...eature=related

^^^love this video, has watched it several times. That focus is fast

[i218127]

Thanks for all the info everyone. I was going to put in a lightened flywheel when I replaced the clutch, but now will not do it. I forgot about the down side of the project.

i218127

[sasquatch]

http://www.youtube.com/watch?v=w-2KiubBNMQ&feature=related

[NicholasJackson]

I think the best way to explain it is this video.

http://www.youtube.com/watch?v=ivBs0DAL7Wo

[link5186]

^ nice anology. Nothing like a physics lesson coming from a serious failure like that. I love and hate seeing pictures like this. It's like a train wreck; you have to look.

Sent from the bathroom via crapatalk

[blkfordsedan]

How can a mass rotating in its center can be thrown in such a way that it does that?

I want replay in slow-mo please.

A spinning object is under constant acceleration, i.e. changing velocity since the direction of motion is constantly changing. Inertia is constantly acting on the flywheel, causing every point on the flywheel to want to continue motion in the direction its travelling at any given moment. This force is not directed outward from the center, but rather at a right angle to it, since the direction of motion is always tangent to the arc of the path. Clear as mud? Think of it this way...

If you tie a rock on the end of a string and twirl it around over your head, you will feel the tension in the string. It will feel like the forces on the string are acting outward from the center, but if you let go of the string when the rock is exactly in front of you the rock will not fly out directly in front of you. Rather, it will fly off to your right or left, depending on the direction of rotation. Where the pieces of the flywheel go depend on what point during rotation they let go, but it will alway be at a right angle, never straight out.

[Nerd Racing]

Flywheels do have a bursting speed, especially Cast Iron ones. I took a mechanical design class and we spent a couple classes on flywheel design. This is why I advise against lightening stock flywheels.

[kartracer46]

He is dam lucky the rotation of a 1.3 wasn't the other direction. That would have been a very bad situatuion. I have had racing clutches on my race kart explode and come through a very thin fiberglass seat. A car like that should almost have a shield installed like a drag car to prevent such accidents.

[Clay]

How can a mass rotating in its center can be thrown in such a way that it does that?

I want replay in slow-mo please.

It is not just a mass rotating about its center. it is transmitting torque.