New old gliders

[Sooner Boomer]

I finally got around to (mostly) finishing a couple of gliders that have been sitting around for a long time. I just found them in the back of the closet, and decided they should fly. The first is a glider I started a *long* time ago. The wing and tail are made from corrugated cardboard. *Somewhere* around here is a Flat Cat made from the lid of a pizza box. The second glider is a ring fin. The booster is salvaged from an Estes glider. Don't remember the name. It had wings that folder across the top of the glider. The plastic bits were red. It never flew right.

 

[Sooner Boomer]

This is a glider that's either one of George Gassoway's designs, or at least heavily influenced by it.




Nose closeup

 

[Sooner Boomer]

The "Ring-Tailed Tooter". The front ring is BT80, salvaged from a rocket given to me. The aft ring is thin-walled phenolic from a dropsonde. Spar is 1/4" x 3/8" basswood.



Nose attachment point

 

[Sooner Boomer]

Booster. It's heavy BT50. Recovers on a streamer.



Attachment hooks

 

[Hobie1dog]

I had to look up what dropsonde was, now we need videos of them.

 

[Cape Byron]

Don't remember the name. It had wings that folder across the top of the glider. The plastic bits were red. It never flew right.

Estes Trans Wing Super Glider? Pic from Launch Lab Rocketry's website https://www.launchlabrocketry.com/shop/p/estestranswing2112

 

[Sooner Boomer]

Estes Trans Wing Super Glider?

Yes, that's it. Never got it to fly correctly. At least it was good for parts.

 

[Sooner Boomer]

Found another glider, an MPC Flat Cat. I flew it twice last Saturday (5/20) at out memorial launch. One of the local members that made his final lift-off was a glider enthusiast. I flew it twice on B6-4 motors. The first time, the glider didn't separate from the booster. The second time, it nose dived straight in. The glider is trimmed for a nice glide. I guess it just doesn't have the ability to get righted from a dive. The college kids at the launch were fascinated by the glider. I think I'm going to have to fly more!

 

[Ez2cDave]

I guess it just doesn't have the ability to get righted from a dive.

Do some research on "Decalage" . . .

https://www.rocketryforum.com/threads/glider-design-trimming-library.155758

Dave F.

 

[shockie]

Do some research on "Decalage" . . .

https://www.rocketryforum.com/threads/glider-design-trimming-library.155758

Dave F.

Aka angle of incidence

 

[Titan II]

Aka angle of incidence

No. They are not the same thing.

 

[Ez2cDave]

No. They are not the same thing.

Correct . . .

http://chuckglider.blogspot.com/2007/12/importance-of-angle-of-incidence-and.html

https://www.amaflightschool.org/getstarted/how-do-i-understand-basic-aerodynamics

 

[BABAR]

Do some research on "Decalage" . . .

https://www.rocketryforum.com/threads/glider-design-trimming-library.155758

Dave F.

Not to be confused with “décolletage”

 

[burkefj]

Not to be confused with “décolletage”

Grand tetons?

 

[BABAR]

Grand tetons?

 

[shockie]

Correct . . .

http://chuckglider.blogspot.com/2007/12/importance-of-angle-of-incidence-and.html

https://www.amaflightschool.org/getstarted/how-do-i-understand-basic-aerodynamics

View attachment 592679

View attachment 592680

Interesting. I've always use incidence angle or decalage to mean the same thing, as every glider I ever built, the wing was 0-0 to the fuesalage, while the stab was usually at an angle of attack to the wing,usually -1 degrees.

While this will balance the boost pitch forces to get a more or less straight flight(actually a flattened "S" curve) it creates more drag force.

On swing-flop FAi S4 gliders, that I built later, the wing is approximately +4 degrees while the stab is 0-0

The problem with 0-0 boost rocket gliders is you need some incidence or decalage to help pull the glider out into a good transition to glide.

This was found out by the Estes Falcon BG, aka the Renger Sky Slash.
The original Sky Slash(Not the one that Estes offered as a free plan) had a string that held the stab flap down during boost, such that it was 0-0 , at Apogee, the engine would eject, allowing the stab flap to pop up.

Estes considered this simple pop-stab, too difficult for the kids of the day to build and trim, so the stab became a single piece. The result was Falcons making a bee line to the ground.

attached is a screen grab of an illustration from an article by Geoff Landis, who taught me a great deal about boost glider stability, especially during the boost phase.

 

[Ez2cDave]

Interesting. I've always use incidence angle or decalage to mean the same thing, as every glider I ever built, the wing was 0-0 to the fuesalage, while the stab was usually at an angle of attack to the wing,usually -1 degrees.

While this will balance the boost pitch forces to get a more or less straight flight(actually a flattened "S" curve) it creates more drag force.

In addition, I generally incorporate 1 - 2 degrees of "downthrust" on the Pop Pod . . .

Dave F.

 

[MJ D]

Yes, that's it. Never got it to fly correctly. At least it was good for parts.

Few did, it was an overweight clumsy piece of crap from the get-go.