Stills of fin flapping phenomenon

[Art Upton]

Since the Booster Bruiser fin flapping video, many on several forums asked to see some stills. Since the fin flapping phenomenon has been interesting to many, I pulled out all the still frames I had since the start of the phenomenon.

Once the fins were gone things got very interesting, and we only have a few still grabs when the video was in sync due to the issues at the time.

50 plus frame grabs can be seen at:

Http://BoosterVision.com/BBN1100

 

[cjl]

Wow!

That really shows it nicely. Considering how stiff 3/16" G10 feels by hand, there must have been immense forces at work there. Incredible.

 

[Rock_It]

.

 

[constevens]

So Art were the fins beveled at all. From the pics they didnt look like it. Maybe some issues with extreme frontal area flow that had an impact on the fins. I know that previously you stated you had not expected to have Mach speeds happening so I could understand why you may not have beveled them. Also after much research on the issue (for my own flights as well that will do mach and have done mach) it seems that maybe for the speeds the fins were also a little large as in sticking outward from the body quite a bit as well as having a large surface area because of the basic shape of the fin ( being a square basicaly with just a section of the leading edge angled back) Most of what has seemed to work for most flights looks to be either in a diamondish or triangularish shapes low profile stuff with different laminates to reduse variants of harmonics. Like a fin I am doing for my L3 G10 laminated with kevlar -carbonfiber-then glass. Anyhow I gladdly love the pics and video as it has helped inspire me to looking harder into the how to fix it situations for myself.

 

[cjl]

Ignore this...

 

[Art Upton]

Originally posted by constevens
So Art were the fins beveled at all. From the pics they didnt look like it. Maybe some issues with extreme frontal area flow that had an impact on the fins. I know that previously you stated you had not expected to have Mach speeds happening so I could understand why you may not have beveled them. Also after much research on the issue (for my own flights as well that will do mach and have done mach) it seems that maybe for the speeds the fins were also a little large as in sticking outward from the body quite a bit as well as having a large surface area because of the basic shape of the fin ( being a square basicaly with just a section of the leading edge angled back) Most of what has seemed to work for most flights looks to be either in a diamondish or triangularish shapes low profile stuff with different laminates to reduse variants of harmonics. Like a fin I am doing for my L3 G10 laminated with kevlar -carbonfiber-then glass. Anyhow I gladdly love the pics and video as it has helped inspire me to looking harder into the how to fix it situations for myself.

not being Mach fins, they had the regular shaping at the ends, sanded to a point in the front over say 3/16 of an inch.

 

[Stymye]

question from the webpage,

what is tri-slotting?

 

[Art Upton]

Originally posted by stymye
question from the webpage,

what is tri-slotting?

This is when you build a fin can design, and need to put your aeroskin over it , you take the body tube you are using for your aeroskin and cut three (or four) slots in the end so you can slip it over the fin can.

 

[Stymye]

so when I slot a tube for a fincan it's called tri-slotting.. I've done that a few times just didn't know the terminology. thanks

 

[Stewart32]

That is phenomenal footage/frames. Were you able to retrieve the ah... remains?

 

[Art Upton]

Originally posted by Stewart32
That is phenomenal footage/frames. Were you able to retrieve the ah... remains?

Yes, we have the remains. The Video has a quick shot of it, looking like a shot down Scud

 

[BHP]

Originally posted by stymye
so when I slot a tube for a fincan it's called tri-slotting.. I've done that a few times just didn't know the terminology. thanks

This is too easy... but...what about four-finned rockets?

 

[Mike Dennett]

Originally posted by Art Upton
Since the Booster Bruiser fin flapping video, many on several forums asked to see some stills. Since the fin flapping phenomenon has been interesting to many, I pulled out all the still frames I had since the start of the phenomenon.

Once the fins were gone things got very interesting, and we only have a few still grabs when the video was in sync due to the issues at the time.

50 plus frame grabs can be seen at:

Http://BoosterVision.com/BBN1100

Hey Art, I am still giggling at this one. Love the stills.

Do it again.. do it again..

 

[Art Upton]

Originally posted by Mike Dennett
Hey Art, I am still giggling at this one. Love the stills.

Do it again.. do it again..

Hi Mike,

We will be doin' it again, belive me