SR-71 Blackbird (Estes)

SPECIFICATIONS:
Length: 19" (48.3 cm)
Diameter: 0.976" (24.8 mm)
Weight: 3.2 oz. (90.7 g)
Recovery: 18" (46 cm) Parachute
Fins: Die cut balsa
Max. Altitude: 600 ft. (183 m)
Recommended Engines: B4-2, B6-2, B6-4, C6-5
The Estes SR-71 Blackbird is a replica of the US stealth plane. When I built the SR-72 kit was given to me by my wife, I decided to build this one, too, sort of big and little brother build. The kit is 19" and very well detailed, using standard parachute recovery. I've decided not to install the motor mount and fly the kit on D and E engines.

CLICK ON ANY PICTURE below to see a larger image.

SR-71 BLACKBIRD KIT

Here are all the parts laid out for inspection. I found some Revell model decals and may use them instead of the ones that came with the kit. Time will tell...
MAIN FINS

Die cut balsa fins. Sanded both sides before removing. Lots of pieces to fit together.

The main fins are created by joining 3 smaller pieces. I was concerned about alignment, so I used the Estes fin alignment guide to glue against. Worked well.

You can see the nacelles have been assembled. The jets and nose cones came as a single piece I had to cut apart then glued in with CyA.

FIN ATTACHMENT

The kit came with some stand to lay the fins on to line them up perfecly against the BT. I loved the idea, but used my own technique for attaching. My method works very well on long fins like this.

Glue goes on the root edge, CyA goes on the root just at the tips, then I set the tip at one end in place til it start to hold, 5 seconds or so, then firm up the other end. 15 seconds and the fins are in place, lined up by eye, and the glue works to set the rest of the fin.



Here is the attached fins resting on the fin stands that came with the kit. I filleted with a light bead of CyA.

OOPS!!

I attached the nose cone to insure the fin alignment was perfect and forgot to take it off when I filleted with CyA. Here's the result when I had to force the nose loose. What a dunce!




Carefully reconstructed the tube shape and firmed up with more CyA. All of this will be hidden under the fin wraps coming up, so I'm not too freaked. Will have to do some work on the nose shoulder, it's a little tight now. Here she is all reassembled and filleted with WHITE glue this time.
PAPERING

The fins that will be visible when assembly is complete have all been papered with adhesive backed 80lb. The corrected BT, very straight fins, is seen in the background.
SHROUD AFFIXED

Carefully followed the instructions to attach the upper and lower shrouds over the BT and onto the fins. Here you see the vise I created with $1 store clamps and hobby sticks.
JET NACELLES

Once the shrouds had dried, I sanded the edges and used my white glue w/CyA on the tips to attach the nacelles quickly. Alignment is good and I went ahead and filleted the seam since I have to wait for the root edge glue to set anyway.

On the negative, the clamps I used left marks on the opposite side I was working on. I should've used hobby sticks on both sides at all times. Hopefully, it will just result in more "character" on the wing details.
OUTER FINS

Used CyA/White glue technique to attach both outer fins. Heavy fillet with white glue.
TOP FINS

The next set of fins are installed at an angle with a cardboard cutout template (not shown). I sanded the root edge at an angle to give a stronger connection after gluing. Used CyA/White glue technique, then filleted with white glue.

BOTTOM FINS

Sanded the root edges at an angle for smoother, stronger connection to nacelles. The template used for correct angle is shown in this first picture. Used CyA/white glue technique with white glue fillets.















Here's a good look at the rear assembly all done! Yes, the bird is upside down, the glue is still drying, so chill out.
LAUNCH LUGS

Well, since it's upside down and I have to wait anyway, on go the launch lugs. I always use a dowel to manipulate the lugs into position and easily hold them in place while the CyA sets. Finish off with white glue fillet.

PRIMER

Here she is getting her first 2 coats of Rustoleum Painters Touch sandable primer.
















Hey look! Here's those "primer fuzzies" so many people were talking about on The Rocketry Forum.
NEXT

more to come...


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