Estes LTV Scout, Build, Part 8, 2nd Stage Adapter Insulation

A build comment: 

I have two LTV’s from way back. One is retired, the other is restored and flies great! I would recommend extending the engine tube past the blow mold adapter below the “Italia” decals. The ejection charge blew apart the adapter on both models. Especially if you sand down the seams, they get very thin. I also use two parachutes for recovery. It’s a beautiful model. 

Good luck! Ken Caldwell

I was also concerned about the hot ejection passing through a blow molded adapter. Hard plastic could probably take it, but blow molded (with some thin areas) maybe not.

Ken suggested extending the length of the BT-20 motor mount tube from the mount through the adapter. I decided on insulating the interior of the adapter.   

I cut a piece of scrap BT-60 about 1/2" longer than the adapter.

Even though I had already widened the hole to 5/8" diameter for the ejection gasses to pass through - 

I cut off more of the adapter end for the tapered tube I was going to install. I did leave some of the turned under shoulder lip.

The BT-60 tube was cut down its length with scissors.

An overlapping cone was formed and slid into the adapter. The overlap was marked with pencil.

An overlap tab was drawn, then cut for an overlap.

The insulating tube "cone" was pressed into the adapter to a tight fit  against the top and bottom openings.

Gluing and trimming in next step.

Estes LTV Scout, Build, Part 7, Great Tubes!

Oh, how I miss the older, tighter better made tubes!

They feel denser and stronger. 

The picture shows the BT-60 tube lower tube. The seams are very tight and were easily filled with CWF,   

The upper tubes didn't need any CWF, I couldn't find the seam recess! Just a good shot of filler/primer and sanding should take care of anything remaining,

Here the shorter tubes are slid onto rolled cardstock handles for a filler/primer spray.

Above - the BT-60 shot with gray filler/primer.

After sanding with 400 grit.

Estes LTV Scout, Build, Part 6, Those Conduits (Tunnels)

I did a dry fit (no glue) to see how the wood tunnels fit against the molded ends.

They were a little higher than the top of the adapter plastic.

The top was take down with 220 grit on a block.

I still left it a hair high to follow up with the next step.

These tunnels are about 1/4" wide, that could leave a gap against the curvature of the tube.

I wrapped some 220 grit around a 3/4" wide dowel and sanded a slight curve into the flat bottom of the tunnel.

This dip running along the bottom will fit the tube better and also lower the top so it will better match the molded tunnel ends in the adapters.

Estes LTV Scout, Build, Part 5, Those Conduits (Tunnels)

Here's how the instructions have you cut and separate the wood conduits.

A difficult task, cutting at an angle using a strait edge and knife.

I cut the first tunnel out, then changed my method.

After trying to sand the sides at an angle, the first conduit didn't seem wide enough for smooth transition meeting against the molded plastic conduit ends.

I ran a pencil down the trenches. I cut the tunnels apart setting the blade centered between the two pencil lines.

On the left is the tunnel end showing the sides extension.

On the left is the before and after. A sanding block with 220 grit smoothed out the sides. Follow with 400 grit.

Estes LTV Scout, Build, Part 4, Engine Mount Gussets

These are probably the thinnest centering rings I've ever run across - The thickness of two layers of 110 lb. cardstock. I've used gussets in the past to beef up an engine mount.

   

I wanted the gussets at a 120 degree spacing or close to it.

A copy paper strip was rolled around the BT-20 tube. Two even folds were made giving three gusset positions.

Wrap around the tube and mark at the folds and where the strip meets.

This is why I save excess balsa left over from other kits.

3/32" thick balsa strips were cut to fit between the two centering rings. These were made a little wide to be sanded even with the outside ring edge after the glue dries.

Here's the final, finished engine mount. 

It's always surprising how much stronger gussets make the mount feel.

This shouldn't be considered "bulletproofing" a LPR model. Just some lightweight strengthening.

Estes LTV Scout, Build, Part 3, Engine Mount

The engine block was installed just above the engine hook slot position using a glue ended dowel.

The engine hook had a slight reverse bend in it.

I bent a gentle curve to better retain the motor.

The instructions mentioned a hold down strap on the pattern sheet (back of face card). There wasn't one.

No big deal. I used a wrap of electrical tape which would last longer than masking tape.

A drop of wood glue was set over the upper bend of the hook.

The finished mount. Those rings are thin!

The upper ring is set down about 1/8" to allow a glue fillet on both sides.

Estes LTV Scout, Build, Part 2, Engine Mount

The low inside end of the engine mount tube got a swipe of CA glue. The edge also got a wipe of glue.

Sand the glued end square with 400 grit.

This end will be exposed, it is not a glued surface. The CA glue seals and hardens the tube end.

 

The engine hook slot cut is made in two steps.

Note the blade is flipped over making two small joining cuts.

Stab and make about half the cut.

Turn the blade over and complete the cut from the other side.

The two facing cuts give you a slot with squared ends - less chance of a tear.

For whatever reason, Estes didn't include an engine block in this kit. I added one.

Estes LTV Scout, Build, Part 1, Parts

Votes in the "Pick My Next Build" were tied!

I drew a name out of a hat. The winner was the LTV Scout.

Here's the parts - 

The 1st stage tube (far right) is an Estes BT0-60.

The three tubes to the left are SBT-127CG, above that a SBT-123BR and finally a SBT-129BJ. Those three tubes are not standard diameters.

The long engine mount tube is a BT-20D.

The small red tube of contact cement and nose weight clay should  not be in the picture. They must have slipped in from the Enterprise kit.

The shock cord will be replaced. The parachute is 18" diameter.

The white adapters and nose cone are blow molded.

I hope the decal sheet is okay for transfer - it looks to be  in good shape.

The fins and lower ring are injection molded plastic.

Instructions. 

Marking guides and tri-fold mount are printed on the back of the face card. 

This is the part that has me concerned -

The conduits are cut from some sort of wood I can't identify. They are rough, meant to be separated with a knife and ruler.

These will take quite a bit of work to clean up and form.

 

Centuri Skylab Build, #KB-4, Finished

This build was more detailed than I thought it would be.

The 3D parts are heavier than the original vacu-forms pieces. 

The Centuri catalog says the weight is 3.4 oz. This build weighs 4.1 oz.

A B6-2 and C6-3 were the recommended motors. I'll launch mine with a C5-3 Super C.

That black turbine exhaust tube reminds me of the exhaust tube on the old Estes Thor Agena B.

The solar panel fins came out very well. They aren't textured but still look okay.

The docking collars are larger and dish shaped. The catalog picture was probably a prototype. The prototype had docking collars that looked like two short lengths of launch lug.

Decals, decals and more decals.

The original kit nose cone was smooth, but I like the raised line ridges on the 3D print.

Centuri Skylab Build, #KB-4, Part 27, Recovery Sling

Horizontal recovery is recommended. 

This would protect the thin vacu-form nozzles at the tail end. This 3D printed nozzle is thicker walled, much stronger than the original kit part.

On my Odd'l Rockets F-104 kit I recommend horizontal recovery similar to what is shown here. The multi piece "T" tail can crack on a hard landing.

Use knots that won't "slide"

I used a simple overhand knot to join both the 12" shock cord to the 12" of string. (Left side of the above drawing.)

The string is #10 cotton embroidery thread. #10 cotton thread is very strong and a bit stretchy.

The lower string to the upper shock cord was joined with interlocking loop knots. (Center inverted "V" in the above drawing.)

The low end of the long string (right side in the drawing) is tied around the large nozzle. 

Tie the knot so that string extension doesn't hit the black exhaust lug or any other pieces that could tangle up at ejection.

Centuri Skylab Build, #KB-4, Part 26, More Details

The Centuri catalog picture shows a prototype build. There is a chrome band around the engine pods. The docking collars are smaller. Some of the decals are different than what came in the kit.

Look close at the detailed vacu-form band. There are some of the raised areas painted black.

The 3D parts included two of the wraps. One was joined to slide over the larger tube. The other was flat, meant to be rolled around and glued to the tube.  

I didn't use the flat one on the model. I used it to practice the black markings like in the catalog picture.

Using the side (not the tip) of a Sharpie, the highest points of the print got some black details. 

This gives an idea of how much black was used.

Just enough - 

Centuri Skylab Build, #KB-4, Part 25, New Turbine Exhaust Tube

After lots of handling during the build, the exhaust tube broke loose.

There wasn't much glue holding it against the motor mount tube.

(The picture on the left shows the first black tube.) 

I cut a new one and filled the seam with CWF. It was sprayed black off the model.

For a better, wider glue bond against the inside motor tube - 

The side of the lug was pushed in to flatten and widen the gluing surface. It took a little coaxing with a fingernail to put a curve in the flattened side.

The lug was sprayed black off the model. The inside end was masked off for better glue adhesion.

Wood glue was used to set the lug against the tube on the inside.

I wadded up a paper towel to put pressure on the lug and position it at the right angle.

After the inside glue dried,

CA glue was applied with a toothpick leaving a hard, clear fillet.

TIP: Cut off just the very tip off the toothpick and round the new end with sandpaper. The wider, round tip will hold more glue for the transfer onto the model.

This second try had a cleaner color separation with it being painted black before gluing into the rear centering ring hole.

Centuri Skylab Build, #KB-4, Part 24, Decals!

I drew up the decals from the scans at Jim Zs. These were sized for the slightly larger diameter Centuri ST-7 tubes.

Shown on the left - 

The second lined wrap decal was cut a bit shorter to fit the BT-20 tube.

When cutting a decal like this,

Round out the clear areas instead of cutting into the corners.

A sharp inside corner could end up tearing.


 

This louvered hatch decal goes over the nose cone.

The 3D print has a raised line.

Smooth and work the decal into the ridge with a wet Q-tip.

Here's the finished nose cone.

Those small camera focus targets are always difficult to set on straight.

Centuri Skylab Build, #KB-4, Part 23, Fin Face Decals

I had to trim the solar panel decals after trying a dry fit on the square fins.

Cuts were made on all four sides almost to the vertical and horizontal lines.

These transferred easily. Wet the entire flat surface before applying the large decal. Centering took a moment or two.

The final look was better than I hoped.

While this doesn't have the raised texture of the original kit stickers, it still gives the right impression.

Centuri Skylab Build, #KB-4, Part 22, Chrome Fin Faces

With the backing still on - 

Fold the chrome trim piece in half so the crease will roll over the leading edge.

Peel off the backing and set the fold over the rounded forward edge.

Don't adhere the entire piece, but pull down on the leading edge pinching between your thumb and index finger.

After the leading is good, then smooth the rest of the skin from top to bottom.

Over time, the chrome cover might lift.

Here's what happened to the Phoenix Bird sticker. I don't think I got a good tight fit over the leading edge.

The piece was cut to the width of the fin but cut a little long to overhand the trailing edge. 

After the skin is burnished, the overhang is carefully trimmed off with a new single edge razor blade.

Here's one of the good fins.

There are some dust specks that make raised areas on the others.

I hope the solar panel decals will camouflage the spots.

TIP: Chrome Monokote Trim material can be hard to find. I got my self-adhesive chrome sheeting from Balsa Machining Service.