SR 71 balsa fin questions

[GusGrissom]

Hi All,

If anyone could assist I'd be most grateful. This is in reference to the Estes SR 71 7003 kit.

In the first pic below, what are the fins next to the question mark for? I don't see them anywhere in the instructions. Did I miss something?

Second issue: The inner wing fins. They don't match the diagram in the instructions and the pre cut line in the balsa was how I cut them. There was no pre-cut line to match the picture in the instructions and I have no idea how I would glue them to the fuselage. Note I circled the discrepancies. Any clues? Thanks for any help.

 

[kuririn]

Hi All,

If anyone could assist I'd be most grateful. This is in reference to the Estes SR 71 7003 kit.

In the first pic below, what are the fins next to the question mark for? I don't see them anywhere in the instructions. Did I miss something?

Second issue: The inner wing fins. They don't match the diagram in the instructions and the pre cut line in the balsa was how I cut them. There was no pre-cut line to match the picture in the instructions and I have no idea how I would glue them to the fuselage. Note I circled the discrepancies. Any clues? Thanks for any help.

The inner wing is made up of three pieces.
The third piece is the mystery fin.

 

[Azamiryou]

Pieces from issue 1 are the solution to issue 2.

 

[Spurkey]

In the first pic below, what are the fins next to the question mark for? I don't see them anywhere in the instructions. Did I miss something?

...you, um circled the question-mark-pieces in red in your second photo. You are over thinking this, something I've of course never ever done in this hobby nope.

 

[GusGrissom]

A thousand thank you's my rocketry brothers. You guys are awesome!!!!!!

 

[Titan II]

See step 2 in the instructions.

 

[ljwilley]

I want to see a build thread! I love the sr71.

 

[Capt. Eric]

I built this kit about a year ago. Not easy, but satisfying in the end. Takes a bit of effort to clean up the joints, fairing, etc. I also had to paint some of the red lines on when the old decals came apart. I also filled in the engine outlets with foam painted orange/red. Maybe should have been blue, but I like it better than empty. Painting it with matte clear was the final wow moment. Good luck with it.

 

[neil_w]

The real 60-year-old (!!!) SR71 continues to be cooler than any sci-fi design since.

 

[rcktnut]

I built this kit about a year ago. Not easy, but satisfying in the end. Takes a bit of effort to clean up the joints, fairing, etc. I also had to paint some of the red lines on when the old decals came apart. I also filled in the engine outlets with foam painted orange/red. Maybe should have been blue, but I like it better than empty. Painting it with matte clear was the final wow moment. Good luck with it.
View attachment 631100View attachment 631101

Are you still waiting for the paint to thoroughly dry? Looks like never launched yet! I would do the same thing, wait, wait, wait some more, paints still not dry. Nice looking model you have there.

 

[Capt. Eric]

Are you still waiting for the paint to thoroughly dry? Looks like never launched yet! I would do the same thing, wait, wait, wait some more, paints still not dry. Nice looking model you have there.

Ummm... no. No problems with paint drying. Dry to the touch within a few minutes. Gave it a day between coats. The pictures were taken when I built it, before flying. But it has flown 2 or 3 times and looks fine. Wind will affect it quite a bit, but it has flown well enough.

 

[Antares JS]

I remember reading a story once about a pilot who had to make an emergency landing, and the closest runway was none other than Area 51. As he was landing, someone demanded over the radio that he not look to his left. Well, what do you immediately do when you're told something like that?

He became one of the first people outside the project to see the SR-71.

 

[rcktnut]

Are you still waiting for the paint to thoroughly dry? Looks like never launched yet! I would do the same thing, wait, wait, wait some more, paints still not dry. Nice looking model you have there.

Ummm... no. No problems with paint drying. Dry to the touch within a few minutes. Gave it a day between coats. The pictures were taken when I built it, before flying. But it has flown 2 or 3 times and looks fine. Wind will affect it quite a bit, but it has flown well enough.

I was just kidding on waiting for the paint to dry. Some of us guys in the club here kid each other when a completed rocket has not flown for a long time after completion, meaning that they are afraid to fly it because it looks so great that they don't want to mess it up.

 

[GusGrissom]

@ Capt Eric: Beautiful job on your SR 71. I had built an SR71 in the early 2000s and now I am back into the hobby. I cannot believe what these classics are costing on eBay now. I guess I just forgot about the mystery fin issue on the SR 71.

I know what you mean about the old decals. I just finished a Starship Enterprise that I had bought on eBay. Unopened package from I think circa 1977 and when I went to do the first water slide decal it basically just disintegrated. I salvaged what I had left and cut them out and glued them on with M 90 spray adhesive with the backing still attached. It doesn't look perfect but what the heck. To quote Rocky Balboa, "I'm just a ham and egger."

 

[Capt. Eric]

@ Capt Eric: Beautiful job on your SR 71. I had built an SR71 in the early 2000s and now I am back into the hobby. I cannot believe what these classics are costing on eBay now. I guess I just forgot about the mystery fin issue on the SR 71.

I know what you mean about the old decals. I just finished a Starship Enterprise that I had bought on eBay. Unopened package from I think circa 1977 and when I went to do the first water slide decal it basically just disintegrated. I salvaged what I had left and cut them out and glued them on with M 90 spray adhesive with the backing still attached. It doesn't look perfect but what the heck. To quote Rocky Balboa, "I'm just a ham and egger."

Thanks Gus.
For some decals that I'm afraid of, I'll scan them into the computer in case I need to make a new set.
Some of the prices I see are a bit nutz to me, but to each his or her own. I don't mind buying old kits, but I don't pay for the "vintage" label. I don't remember what I paid for that SR-71, but it wasn't crazy. I might have a source for another. Might have to pick it up for insurance purposes.

 

[Capt. Eric]

I was just kidding on waiting for the paint to dry. Some of us guys in the club here kid each other when a completed rocket has not flown for a long time after completion, meaning that they are afraid to fly it because it looks so great that they don't want to mess it up.

Ok. Gotya. I take to heart the saying "It's a model until it flies. Then it's a rocket." So I fly everything I build, although sometimes with some trepidation. My Estes Saturn 1B came out nice. Flew once, quite nicely. No real damage. But with those fragile fins all around the bottom, I'm not so sure I will fly it again.

 

[grapetang]

Post pics! We love build threads!

Here's one my kid & I built:
https://www.rocketryforum.com/threads/estes-sr-71-blackbird-clone-build-thread.174691

If you want to make it a little closer to scale:
- recut & flip the ventral fins around (large edge first, with grain running parallel)
- top vertical stabs are 15 deg off vertical; bottom are 11 deg (10 will do)
- We didn't do this but bonus if you can shorten the nacelle tubes to 6". Line up the front, keeping the wings & stabs in their original positions. Just the tail cones move forward by 0.5" from their original positions.

Good luck!

 

[GusGrissom]

Allright before I post pics, let me warn you, here's what I've built so far, note the paint jobs and the launch escape towers. I'm not the most talented builder but I try.

 

[GusGrissom]

OK, here we go:

The paper wing jigs are very important. Don't discount them. they were very helpful. Attaching the engine pods was more stressful than my first job interview after college.

 

[GusGrissom]

I really love the look of this plane/rocket. I built one 20 years ago during my first foray into the hobby. I thought Estes forgot to include the engine nozzles but they were attached to the exhaust ports and I found them when I pulled out the ports from inside the tubes. They had to be cut apart. Getting the angle right on the top wing fin was tough. I used painters tape to hold the fins in place while drying. It probably isn't perfect going to be the perfect angle. I found that if I repeatedly stick and peel the tape off of glass several times it makes it less sticky so when I take it off it doesn't pull whatever I've glued off with it. Okay, all caught up for now.

 

[GusGrissom]

Oh there is one more thing. Don't forget to erase all those pencil marks on the doorframes where you marked your tubes before the wife gets home!

 

[GusGrissom]

Got both upper and lower fins placed, think I got the angles ok. The tick marks are off slightly for the placement of the launch lugs (again, I'm not the most talented modelmaker) but I'll just go by the body lines I drew in pencil.

 

[GusGrissom]

OK, I'm all done. Here's the final pics. Some amazing builds from all who contributed here. So glad to get the assistance and encouragement from so many talented people here. Without your help I wouldn't have made it past page 2 of the instructions. Thank you all so much.