SR-71 or SR-72?

On the NAR Facebook page, Frank Burke posted a picture of his latest R/C Boost Glider:

"YF-12 interceptor version of the A-12/SR-71 family. Hardly ever modeled. This was an interceptor version that wound up being used for testing the aim 47 missile and doing tests for NASA. The chines were shorter on this design because of the large rounded nose cone that held the radar system. The R/C Rocket glider uses 9mm depron, bt80 tubing and is designed for 32mm glider G-12 reloads. Currently 16 oz airframe weight. with electronics, paint, nose weight and motor it'll be about 26 and 1/2 ready to fly so it should be a pretty good performer."




I thought this profile looked familiar. I put together the (much smaller) Apogee SR-72 Darkbird a while back. 
To see the build: CLICK HERE

At the time, I asked Tim at Apogee where he came up with the name. He said: "We wanted to show the next generation of the SR-71, we call ours the SR-72."

Looks like the Apogee kit was based on the same YF-12 Interceptor that Frank built. I never even knew it existed.

Estes Low Boom SST #7289 Build, Part 1, Parts

Here's another new kit design from Estes.

It's BT-55 based and uses the interceptor nose cone.
It's a builder's kit, some extra time will be spent on the jet engine assemblies.

All the parts - That's a pre-assembled 15"parachute.

The balsa sheets hold the wing and jet intake pieces. (Third sheet not shown here.)
One of the new screw on 18mm engine retainers is included.
The BT-20 internal engine mount tube doesn't have a glassine clear coat. This tube is enclosed and won't be seen.
The great Interceptor nose cone.

Estes Leo Space Train #7285, Finished

Lots of pictures of this one! A lot of details to cover.
The tough part of this kit are forming and filling the small actuators. To match the face card color scheme, I do recommend painting the colors separately before the glued assembly.
This is an impressive model, the new C5-3 motor should fit it well. 

Estes Leo Space Train #7285 Build, Part 13, Assembly & Scraping

The big nozzle was glued on the motor tube using Beacon Fabri-Tac.
The screw on retainer hub followed.

The auxiliary small rocket "runners" were set in place and the line marked with pencil.
The lines were carefully scraped to open up a glue area.


To smooth it out and widen the line a bit, some 220 grit was tightly wrapped around a Q-tip. This was sanded back and forth down the line. Keep the glue line narrower than the runner width.

This was a tricky scrape!

Carefully mark the intersections with pencil, scrape the lines with a knife blade.



The upper engine is glued on with the tube back ends even.

Right down the center -
A heavy glue bead was applied to the wing.

The large body tube assembly was set into the glue. Carefully check alignment as the glue is drying.

Estes Leo Space Train #7285 Build, Part 12, Another Mask & Gluing It Together

The black on the underside is extended back, down the tube from the lines already masked on the nose cone.



This was my first build, the second and third builds had the black extended all the way to the back of the main body tube.

The gray support assembly, parts H, I, J and K were glued onto the top of the wing center.

TIP: Here I used a paper towel to make for a soft clamp that won't scar the balsa wood.

This is the back end clamp.

The upper engine had the black nozzle assembly glued in.


The nose cone fit was loose and needed a wrap or two of masking tape for a good fit.

Estes Leo Space Train #7285 Build, Part 11, Details & Decals

The actuators (Parts P) were glued onto the wings and stabilizer sides. Paint was carefully scraped away for gluing.
The locations are laser cut into the wings.





I'm jumping ahead here -

The small dot recesses were blacked using a fine point Sharpie marker.







The kit I received was pre-production, the decals I used were printed at Estes.

The rectangles were supposed to be filled with white ink, but this was a ink jet printed decal with no white ink.

TIP: To get white decals -
I soaked the black outline rectangles and slid them onto a blank white decal sheet. After it dried, I cut out the double layers right around the outside black border line.




These were soaked and both decal layers were slid together (stacked) on the underside of the wing.
This was a "get-by" that really added some high contrast. The production kits (now on sale) have these decals in white.

Estes Leo Space Train #7285 Build, Part 10, Masking Black Wing Leading Edges

To match the face card and catalog pictures, this will be an involved mask.

The underside is all black.

The wing was already painted gloss white.
The lug was painted gloss black. No real reason for pre-painting the lug it would have been black in the end.
The lug gluing area was scraped for a good glue bond.







The leading edge is painted gloss black. The picture shows the mask. Scotch tape is along the color separation line, masking tape covers most all the other open areas.

Here's the top edges mask.

Note in the last picture the center are is masked for the I, J and K pieces. Those are painted gray, separately before gluing onto the wing top.








The black edges are painted and tape pulled.