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.

Sorry, no posts for a few days -

 I've got more Odd'l Rockets kit orders than I can handle right now -

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 17, Adding The Second "Finlet"

I drew a pencil line for the second finlet by sighting down the nose cone tip.

This seemed iffy, I matched the straight angle by matching the knife angle to the finlet in the nose cone.

Removing the finlet you can see the slot that was crushed into the balsa. It's actually pretty clean, a tight fit.

The second finlet is pressed into it's slot.

I was lucky - the alignment is good.

After adjusting the height of the finlets, there was a small gap at the bottom of one slot.

A wedge of balsa was cut and pressed into the void. The edges of the finlets should be rounded.

Here's the two nose cones (balsa above the 3D print) compared side by side. If the balsa cone were filled and painted I doubt you could tell the difference. The basswood finlets are a little thicker.

They are the same length, there is a little photo distortion.

Estes Aries SST, #1927, Build, Part 16, Making a "Finlet" Nose Cone

If you don't have a plastic PNC-50S nose cone (with the finlets) You can make one using a BNC-50Y balsa nose cone and some 1/16" thick basswood.

When researching this build, I checked the old Vashon Sandpiper instructions. To see them, CLICK HERE

The balsa nose cone gets a slot cut, and the tapered canard root edge is pushed into the slot. 

I thought this would be iffy, but I had an extra BNC-50Y nose cone to experiment with.

The finlets (or canards) pattern is on the PDF available to Patreon subscribers.

The Vashon kit used balsa, but I'd recommend using stiffer basswood.

Cut out the pattern and trace onto 1/16" thick basswood.

The distance behind the trailing edge of the finlet to the shoulder lip is just under 1 3/4".

Mark a straight line with pencil the length of the root edge.

Mark the depth of the exposed root edge on the finlet.

Using a sanding block, sand a sharp taper to the inset tab.

Cut a slit about the depth of the inset tab. There is no need to cut and remove balsa.

Cut another slit on both sides, just to the side of the first slit. Side by side, the three slits are about 1/32" in width.

You should be able to press in the tapered tab up the root edge pencil line.

Estes Aries SST, #1927, Build, Part 15, Decals Ready For Patreon Members

The Aries SST decals are available to Patreon supporters.

You can request the decals at: oddlrockets@bellsouth.net

There are usually extras on my decal sheets. These are for soak time and transfer testing. Extras also fill out the sheet.

On the second PDF are the fin patterns and shrouds. The shrouds are marked for a better, closer trim if you decide to round the leading and trailing edges of the wings.

Another PDF, just released is the Estes BT-50 based Sandpiper. The Air Force logos have white decal underlay patterns.

This is a double decal sheet.

A second page holds the fin templates and shrouds.

If you are a Patreon subscriber, ask for the Estes Sandpiper PDF through: oddlrockets@bellsouth.net

If you don't have access to a 3D printer -  in an upcoming post -

I'll show how to make the "finned" nose cone using a balsa cone and thin basswood (or ply).