Estes Mini Scale Combo Pak, #0874, Tomahawk & Exocet, Build, Part 9, Gluing On The Fins

The Tomahawk marking guide ends matched up when wrapped around the tube. I marked the fin locations.

TIP: Always check the guide by rotating it one quarter turn around the tube. At the second mark, the pencil mark didn't line up with the arrow on the guide!

I made up a marking guide and got the fin lines evenly spaced. 

A wrap of tape insured the tips of the root edge were at the same height. This is one of the few models where the trailing edges aren't even with the low end of the tube.

Glue fillets followed - 

On the left, the primer has been sanded down to the body tube for the launch lug to be centered between two fins.

On the right, is the shock cord cover position not in line with the launch lug.

That raised cover might cause friction with the launch rod.

Estes Mini Scale Combo Pak, #0874, Tomahawk & Exocet, Build, Part 8, Covering The Shock Cord

It's easier to use tweezers to grab the end of the shock cord.

Pull the cord through the slit until 1/4" sticks outside the body tube.

I traced around the paper shock cord anchor, then scraped off the gray primer for a better glue bond.

Apply glue to the back of the exposed shock cord and press the cord down onto the body tube until the glue sets up.

Glue the paper anchor over the shock cord and body tube area.

Use the center marks to line it up. Shape with a burnisher.

When the anchor is still wet with glue, you can shape and mold the paper cover.

I won't know how good this will look until paint is applied.

Estes Mini Scale Combo Pak, #0874, Tomahawk & Exocet, Build, Part 7, Slitting For The Shock Cord

The shock cord install reminds me of the oldest kits. You made two slits in the body tube and laced the shock cord through them. You were left with unsightly cuts and a bulge after the paint was applied.

Maybe this simpler single slit and paper cover will look better.

The shock cord "anchors" are cut form the instruction sheet.

A 1/8" wide slit is made 3/4" down from the top of the body tube.

Notice I pencil marked the 1/8" wide slit position before cutting with a knife.

The nose cone shoulder is only about 1/4" long so you will have enough clearance.

Cut the slit - 

Fish the shock cord end into the slit using the tip of your hobby knife. This ended up being easier than I initially thought.

Estes Mini Scale Combo Pak, #0874, Tomahawk & Exocet, Build, Part 6, Installing The Engine Blocks

In the instructions, both of the two models have a slit cut in the upper body tube. The shock cord is fed through the slit. The exposed shock cord gets a paper cover glued over the top.

One model will get the slit tube method, the other will get a Kevlar line tied to the engine block.  

A notch is cut into the outside of the engine block. The Kevlar line is tied and tightened over the notch.

Feed the Kevlar line through the middle and out the bottom.

The original yellow engine spacing tube was missing. I cut a BT-5 coupler to 1 3/4" long.

The fit in the tube was tight so I peeled off the outside layer for a slip fit.

The spacing coupler is pencil marked 1/4" from the bottom.

Slip the Kevlar line through and out the bottom of the spacer coupler. The engine block rest on top of the spacer coupler.

Apply a bead of glue 1 1/4" inside the low end of the BT-5 tube.

Push the engine block in and into the glue up to the pencil line on the spacing  coupler.

For now, leave the Kevlar line out the back of the model.

The second model got an engine block without the Kevlar tie.

Estes Mini Scale Combo Pak, #0874, Tomahawk & Exocet, Build, Part 5, Joining Tubes

Always round over the corner ends of couplers for a smoother slide in the tubes.

This coupler is marked 3/8" from the ends with a center line.

The coupler is glued into the longer tube.

The shorter tube is glued on top, over the coupler.

 

The joint seam is filled with thinned CWF.

Dip a knife tip into the CWF, drag the filler bead around the seam.

Sand the joint with 400 grit on a sanding block.

Estes Mini Scale Combo Pak, #0874, Tomahawk & Exocet, Build, Part 4, Finding Parts

One of the lugs was missing from the opened kit. 

On the left is the original, yellowed with age lug. The longer lug is for the Tomahawk.

On the right is the same length lug, cut in half for the Exocet.

One screw eye and one nose weight washer were in the bag.

I went to my hardware bins to find the smallest screw eye and washer. I always save leftover screws, bolts and washers from previous projects.

The two washers are for the Exocet.

Here's the different length lugs after filling and sanding the CWF.

The older, longer lug had tighter seams than the new lug on the right.

Estes Mini Scale Combo Pak, #0874, Tomahawk & Exocet, Build, Part 3, Fin Prep

All the outside edges (not the root edge) get a narrow bead of glue.

Smooth and even the bead with the side of a finger.

After the glue dries, the fin edges are sealed.

Sand the dried glue with some 400 grit.

The root edges are set against each other to keep them clear of the filler/primer.

The fins get a good shot of filler/primer.

Estes Mini Scale Combo Pak, #0874, Tomahawk & Exocet, Build, Part 2, Fin Prep

The die-cut hold down "tics" have to be cut through and extended to finish off the tip of the leading edges.

 

Start the blade cuts below the gap and continue straight up through the open tip.

Stacking the fins shows how much the die-cut blades were off.

Sand and even up the sides. Hold the four fins tightly, the cardstock is slippery!

The top of the die-cut is slightly rounded. 

On the left - The back side shows raised pressure crushing. 

On the right - The fin back side was sanded flat with 320 grit on a block. 

To smooth the rough edges, the fins will require some filler/primer sprays and sanding.

Estes Mini Scale Combo Pak, #0874, Tomahawk & Exocet, Build, Part 1, Parts

I always found this combo "Pak" kit interesting.

The eight finned Exocet and I.Q.S.Y. Tomahawk.

Produced from 1986 - 1989.

BT-5 based mini engine kits.

No parachutes or streamers, just break-apart recovery.

An interesting single slit shock cord anchor.

From the Estes catalog:

“Two scale rockets in one package feature balsa nose cones, scale decals, die-cut fiber fins and break-apart recovery.”

Flights to 800 feet.

The BT-5 body tubes are 5" and 3" long, joined by a coupler. I don't know why there are joined tubes, a single 8" long tube would have easily fit into the kit bag.

The kit fins are die cut thick cardstock.

The rubber shock cords are 6  1/2" and 7 1/2", too short for me.

NO parachutes or streamers - I'll add longer shock cords and streamers. 

This was an open bag kit, given to me by Roger at Jonrocket.com.

There were some missing parts: 

Two washers are needed for the Exocet nose weight, only one was in the bag.

Only one launch lug was found, a second one will come from my spare parts stash.

Only one small screw eye, I know I have a second one upstairs.

Estes Aries SST, #1927, Build, Finished

This is one of those kits that comes alive when the decals are applied. A winning visual combination - Big graphics in three colors.

The top of the wings - 

The bottom of the wings with the landing gear doors.

The top and bottom views of the nose - 

I don't know what these red rectangles are but they fill some space! Many kits don't supply many decals on the underside.

Estes Aries SST, #1927, Build, Part 18, Decals

The upper wing decals - 

Set the black rectangles down first.

The red/black stripes should fit close but not over the leading and trailing edges of the wing. The rear of the decal almost matches the curve of the trailing edge.

Notice how the long window decal is cut out at the front end to clear the canards (finlets).

Before you set the decal down - 

Be sure the canards are in line with the wing. VERY IMPORTANT!

The nose cone is slid all the way in, against the end of the body tube.

Set the decal down, it will overlap the nose cone / body tube end.

After the decal dries, cut at the body tube / nose cone joint.

Here's the underside of the body and nose cone.

Estes Aries SST, #1927, Build, Part 13, Moving The Launch Lug

I got the launch lug placement wrong! 

I'm usually on top of these things, but for whatever reason the launch lug was glued on the top when it should have gone on the underside. 

    

I didn't glue fillet the lug, so the removal was fairly easy.

The glue that was left was sanded off using 400 grit.

Mask off the area just around the glue sanded area.

Notice the edges of the masking tape are raised so the sprayed paint will feather in instead of having a sharp edge.

Carefully spray just the open area -

After the paint dries, light sanding follows. Another coat may follow if the surface isn't smooth.

Estes Aries SST, #1927, Build, Part 12, White Paint

Assembly is complete except for the parachute and shock cord ties.

Time for paint! Note the dowel/engine casing painting wand locked in the engine mount. I tend to leave this handle in through much of the build, paint and decal placement. It's easier to hold and not as risky for fingerprints.

This shows some of the spots where the sanding has removed glue blobs. The intake fillet also had some high spots. 

I've been using Ace Premium Enamel (Ace Hardware brand) spray paint for a while now. Shoot when humidity is low, around 2:30 in the afternoon. 

The Ace paint dries to the touch in about an hour, recoat within an hour or after 48 hours.

After one hour I was able to handle the model and do the initial undercoat sanding shown above.

Estes Aries SST, #1927, Build, Part 11, Gluing On Launch Lug & Rudders

I no longer waste time with glue fillets on the sides of launch lugs. That glue line was straightened and the width narrowed by pinching your thumb and index finger together. 

Run your finger "V" down the lug making a straight, narrow glue line. 

Carefully place the lug with the glue on the pencil line, 1 3/4" from the rear of the main body tube.

Here's the rudders glued onto the wing tips.

Assembly is finished, ready for white undercoats.

Estes Aries SST, #1927, Build, Part 10, Fitting The Rudders To The Wing

Stack the rudder assemblies to be sure the glued angles are consistent.

If they don't line up, apply a little warmth with the low setting on a heat gun and gently bend at the glue joint to match the other rudder assembly. 

On the outside (visual) seam,

Drag some CWF down the joint and immediately smooth and remove excess with a fingertip.

Sand after the CWF dries.

The outside side seam is sanded flat for a stronger glue joint against the edge of the wing.

Use a sanding block but don't go any wider the the 3/32" thickness of the wing.

Estes Aries SST, #1927, Build, Part 9, Sanding The Rudder Edge Angle

The root edges of the rudder fins have to be sanded at an angle.

Mark the flat root edges shading with the side of a soft pencil.

The picture on the right shows the angle sand about halfway through. The pencil shading gives a better contrast so you can sand the line evenly.

I'd recommend using a sanding block, like the Estes Ultimate Sanding Bar. To reach a 3/4" dihedral height, the sanding angle is not very steep. 

On the right, you can see what's left of the pencil line. Sand until the pencil shading is gone - no further.

With a weight on one side of the rudder assembly,

Raise the other outside edge to 3/4".