QUESTION About DOORKNOB Details . . .

[Ez2cDave]

Does any data exist showing the details inside the 12 openings in the Doorknob airframe, near the top of the Fins ?

I know that it uses the motor from the Lacrosse.

I think that there may be some type of bolts / fasteners which are accessed through those openings.

Dave F.

I suspect that the arrangement may be similar to the ASTROBEE 1500, but inverted . . .

Dave F.

 

[SolarYellow]

View attachment 450337

Interesting that the LE taper on the fins in that photo is clearly different than how it's drawn by Alway in the Sport Rocketry drawings attached further down in the thread.

 

[Ez2cDave]

I tired a little "photo scaling" . . .

Dave F.

 

[Ez2cDave]

This is what the LACROSSE rocket motor looks like . . .

 

[Bruiser]

"Interesting that the LE taper on the fins in that photo is clearly different than how it's drawn by Alway in the Sport Rocketry drawings attached further down in the thread."

There were two types of fins. I've attached a page

-Bob

 

[Ez2cDave]

"Interesting that the LE taper on the fins in that photo is clearly different than how it's drawn by Alway in the Sport Rocketry drawings attached further down in the thread."

There were two types of fins. I've attached a page

-Bob

Yes . . . Looks like the same plan-form, but with different airfoils, on each stage.

 

[SolarYellow]

Studying all the Sport Rocketry material, it makes sense. The more common fins were flat plate, constant thickness, with a constant width LE taper. The "tapered taper" is where the fins were tapered in thickness from 0.5 inch at the root to 0.25 inch at the tip. Consequently, the LE taper, presumably maintaining the same geometry, was reduced in width correspondingly.

So it's reasonably scale to make constant-thickness, flat fins with just the LE taper if you don't want to have to taper from root to tip. You just might not be matching the exact configuration of a particular flight perfectly.

 

[Jack Hydrazine]

I don’t remember where I found this info n the Doorknob - the drawings are, of course, by the redoubtable Peter Alway. FYI I didn’t scan or swipe these so if Mr. Alway happens across this post I apologize for breaking any copyright or fair use rules - I have a special change jar setup just to save up for the next version of ROTW when he gets it done

I looked at the scans of the "Sport Rocketry" and see pages 10, 11, 14, and 15. The text of the article looks like it should continue to page 12 or 13. There might be an advertisement on one of those missing pages. Is it possible for you to scan the missing page(s)?

Thanks!

 

[gburke568]

Which scans are you looking at Jack? The Sport Rocketry Sept/Oct. 1999 scans on the Nar website, are all present and accounted for.

 

[gburke568]

I looked at the scans of the "Sport Rocketry" and see pages 10, 11, 14, and 15. The text of the article looks like it should continue to page 12 or 13. There might be an advertisement on one of those missing pages. Is it possible for you to scan the missing page(s)?

Thanks!

Which scans are you looking at Jack? The Sport Rocketry Sept/Oct. 1999 scans on the Nar website, are all present and accounted for. I compared the one on the NAR site to a actual copy of the magazine..

 

[Jack Hydrazine]

Which scans are you looking at Jack? The Sport Rocketry Sept/Oct. 1999 scans on the Nar website, are all present and accounted for. I compared the one on the NAR site to a actual copy of the magazine..

Nevermind. I found them. Thanks!