Estes Cosmic Interceptor Build, Part 5, Fitting The Vanes

The engine hook retainer ring is rough with a wide seam that could be seen when painted.

I added a wrap of copy paper with a glue stick. This smooths out the surface and covers the seam spiral.

I sealed the surface with some CA glue wiped on with a Q-tip.

Notice the CA glue is not applied on the line where the vanes will be glued.

On the left is the glue applied to the vane root edge.

On the right is the same glue line after smoothing and removing the excess. This makes a cleaner glue line when the vane is pressed in place.

Set the first four vanes in a standard cruciform pattern.

When setting the other four, you might want to rely on visual spacing instead of strict pencil lines. Even with my payloadbay.com marking guide, I found a visual spacing was closer to the truth.

On the left - Notice the fit of the two vanes that glue beside the engine hook. Over the engine hook, the retainer ring is raised. 

On the right - The center notch was deepened with a diamond file to bring all three contact points onto the tube.

Estes Cosmic Interceptor Build, Part 4, Prepping The Engine Mount Tubes

There are many tubes in this kit - I'll be filling seams as I go.

The engine mount tube and the short tube that goes over the vanes got the seams pencil marked.

Thinned CWF was dragged into the seams using the tip of an old X-Acto #11 blade.

After it dried, sanding followed to surface with 400 grit.

I know - I'm filling an inside seam.

I won't know how visible this will be until the vanes are glued on.

After filling, more sanding.

The two tubes got a shot of Duplicolor Filler/Primer (FP101) and sanding. Two steps and the seams are filled.

The engine mount marking guide didn't quite match up around the engine tube. 

A comment once said: "It won't match up after the tube diameter is increased if the seams were filled."

The wrap was placed at the upper end of the tube where no filling was done. A new marking guide was printed at payloadbay.com.

To place the engine block, tape wraps were done at the 1/2" mark.

Estes Cosmic Interceptor Build, Part 3, Prepping The Engine Vanes

Lightly sand the laser cut ash edges with 400 grit.

The pics show the before and after sanding.

The exposed edges (shown here marked with pencil) should be sealed. If not sealed, the paint will soak into the open fibers and the edges will be uneven.

A segment of tubing will glue over the edge without the pencil line. 

Run a narrow bead of glue down the side edges. 

With the side of your finger, even out the bead getting a rounded even coverage from side to side. Remove the glue from the sides of the vane, leaving only a rounded bead over the edge.

After the glue bead dries, lightly smooth with 400 grit.

Estes Aries SST, #1927, Build, Part 2, Engine Mount

The engine hook and Kevlar line relief notches are initially cut with a knife. 

Instead of picking out peeling out the wrap layer between the cut lines, I use diamond files to remove the recess. This makes a cleaner notch, especially on the Kevlar side. 

I don't apply a ring of glue then slide the centering ring onto it. Instead, I slide the rings on dry, apply spot glue at the joint and then smooth them. After the spot glue dries, it allows me to tighten the Kevlar wraps without the rings sliding around. Then apply full glue fillets

Note the upper ring is centered over and on top the upper bend of the engine hook. This makes a stronger mount - instead of the upper ring positioned above the upper bend of the hook.

Tighten the Kevlar wrap, then apply the glue fillet over the the Kevlar wrapped line.

An engine block wasn't included in the original kit, I added one, even with the tube top when slid against the top bend of the engine hook.

A 1/16" diameter heat shrink tube was slid down the Kevlar line and hit using the low setting from a heat gun.

Hold the heat shrink end down against the top of the upper centering ring. The after pics shows the tubing hugging tight over the Kevlar line.

Note the shrink wrap starts below the top of the engine mount tube. This protects the the low end of the Kevlar line.

Estes Sandpiper, Kit #1389, Part 3, Tail Cone

Payloadbay.com is down right now, that's usually my source for cardstock reducers and tail cones.

I did my best to size the kit pattern sheet (CLICK HERE) but there was no 1" reference in the image.

Crossing my fingers, I test fitted the shroud dry and marked the overlap line. In the picture, I'm burnishing down the glue tab. 

I'm using a heavy wall BT-50 and a standard BT-20 engine mount tube.

This will require some fitting, the heavy wall BT-50 has a slightly larger diameter over a standard BT-50.

The engine mount was glued in place with the lower centering ring extended out the back, about 1/16". This picture shows the assembly upside down.

To fit the imperfect shroud, I had to use some paper wraps. Two 20 lb. copy paper strips gave a good friction fit.

Light glue was applied and the shroud slipped in place.

Before the glue sets up, you can do some "molding" of the still wet shroud edges. I'm using the smooth barrel of a Sharpie pen to press the shroud edge against the body tubes.

Estes Sandpiper, Kit #1389, Part 2, Engine Mount

The instructions have you set a line of glue 2" up inside the 3 1/2" long BT-20 tube. Then push the engine block up from the bottom.

The engine mount tube is only 3 1/2" long, I can add a glue fillet from the top.

Tape and engine casing with 1/4" extending out the bottom. Slide the engine block in from the top dry, no glue yet. 

Slide the block down until it stops against the top of the engine casing.

Add glue using a Q-tip making a fillet around the joint.

After it is dry, remove the engine casing.

The upper 2050 centering ring gets a notch for the Kevlar shock cord.

There is very little room between the tubes for a knot, I did a wrap.

Tighten the Kevlar, set it into the glue fillet.

New Way Lunar Jumper Build, Part 3, Engine Mount & Shock Cords

The engine mount assembly is standard. A slip over coupler holds down the middle of the engine hook.

Here, the Kevlar line is tied beneath the upper plywood centering ring.

There isn't much space between the outer BT-50 and BT-20 engine mount tube. A larger square knot could bulge out the BT-50 tube wall.

I used an overhand knot, but rolled the Kevlar over and under the wrap 4 times. This still allows the wrap to be pulled tight and keeps the line close to the engine tube.

The wrap is set into the wet glue centering ring fillet. The loose tail is cut off and also set into the glue fillet.

The picture to the right shows the heat shrink tube slip down to the top of the ring, protecting the Kevlar line. 

The short shrink wrap is slid over the tied knot joining the elastic and Kevlar line.

Near the elastic, be careful with your heat gun - 

TIP: Using the low setting on my heat gun, the elastic started to melt!

I had to cut off the old knot and re-tie the elastic and Kevlar. I might tie an additional piece of elastic to the shorter line joined to the Kevlar.

The second time, I kept more distance between the heat gun and the heat shrink tube.

Second try was good! (Maybe that's why two pieces of tubing were included.)

Micro-Maxx Estes Fat Boy, Part 8, Engine Mount & Streamer

The engine mount was slid in until the MMX motor was higher that the trailing edge tips of the fins. I didn't want the model standing on the engine mount tube.

After I was sure of the engine mount position, a glue fillet was applied using a Q-tip. 

The body is short so an upper glue fillet was also applied around the forward centering ring using another Q-tip.

The Kevlar line is tied to the elastic loop in the nose cone base. The loose end was pushed into one of the holes in the shoulder plug.

A plastic streamer was taped onto the Kevlar line one third the way down form the nose cone tie.

Estes Shark #1111, Build, Part 8, Engine Mount & Fin Gluing

Set the engine mount and Kevlar line alongside the lower, longer tube.

The BT-20 engine tube is even with the bottom of the BT-50 main body.

This gives you an idea how long the Kevlar line should be, a little shorter than the top of the BT-50.

Tie a overhand loop knot (shown on the right) for the elastic shock cord attachment.

I used epoxy to glue the mount in, allowing me some positioning time.

Here's the BT-50 tube with the filler/primer scraped off where the fins will be glued. The scraping is a little shorter than the length of the leading edge.

The low fins are glued even with the end of the body tube.

On the forward fins and thrusters, I used a wrap of masking tape as an low alignment line at the corner of the trailing edges.

Estes Shark #1111, Build, Part 3, Engine Mount

The 20/50 rings were notched for the engine hook and Kevlar line.

The lower ring is on the left. I highlighted the notch with pencil.

The upper ring is on the right. Note the Kevlar notch directly opposite the engine hook  notch.

The instructions would have you position the upper ring above the top bend of the engine hook. I position the upper ring lower, over the top of the hook end making a stronger mount.

The Kevlar line is set directly opposite the engine hook.

The loose end of the Kevlar line is pressed into the upper ring glue fillet.

1/16" diameter heat shrink tubing is slid down the Kevlar and rests against the top of the ring.

Hit the heat shrink tube with a heat gun, shrinking it around the Kevlar.

Estes Time Warp Build, #7321, Part 5, Upper Centering Ring

Here's the upper laminated centering ring,

glued 1/2" from the bottom of the BT-5 tube cluster.

The instructions say to add glue fillets down and between the three tubes.

TIP: I wouldn't do this, it's a long, deep joint. When the glue dries you'll have bubbles and an uneven fillet.

I used a few drops of glue to fill the small center gap. This will block any ejection charge escape.

Years back we used "tissue/glue putty" to fill gaps like this. Tissue/glue putty is a mix of glue and tissue torn into very small pieces. It makes a strong gap filler.

This gap is small, if it were larger I'd make up some tissue/glue putty.

To read more about this gap filler: CLICK HERE 

This top and bottom glue fill also strengthens the mount.

Estes Time Warp Build, #7321, Part 4, Centering Ring Laminates

The center triangle of the centering rings will probably break off. There's not much to hold it in the center.

I'll show how to block the hole (and the ejection charge) in the next post.

When laminating the two sets of two rings, 

use one of the BT-5 tubes to check the alignment.

Don't glue the tube to the rings (yet), use the tube to be sure all three holes are lined up.

The instructions suggest sliding the ring down from the top into a glue ring.

For a cleaner build and less visible glue -  

I slid the centering ring up from the bottom pushing the glue ring up. It's a cleaner visual outside joint on the finished model.. 

You don't have to use much glue, you can always add a glue fillet later.

Estes Time Warp Build, #7321, Part 3, Engine Blocks

Jim Flis (Fliskits) gets credit for this engine block setting idea calling it the "Block and Tackle.".

TIP: The mini motors (friction fitted) extend 1/4" out the rear of the BT-5 tubes. 

A 1/4" strip of masking tape is wrapped around and even with the end of the yellow spacer tube. 

This tape ring stops when it hits the end of the tube. 

All three engine block will be at the same depth.

The instructions the engine block glue line at 1" inside the tubes.

I'd recommend using a dowel pencil marked at 1 1/4" to apply a ring of glue inside the tube.

Apply the glue ring, slide in the engine block. Use the taped yellow tube to set the ring depth.

The three BT-5 tubes are ready for the centering rings.

Estes Time Warp Build, #7321, Part 2, Paint Plan & Engine Tubes Fill

Planning ahead!

If you want to paint the rocket in the face card colors, paint the build in sections before gluing it all together.

The BT-5 cluster tubes are yellow and would be difficult to paint if glued into the gray BT-55 tube.

That yellow adapter could be painted before gluing into the white BT-50. Same goes for the gray nose cone. Paint them before gluing together and get instant "masks" or color separations. 

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The lower centering ring is glued 2" down from the tops of the BT-5 motor tubes. I filled the tube seams below that.

The seams were shallow, here you can see the pencil lines where they could be felt.

CWF was used to fill the bulk of the seams and sanded smooth.

The upper 2" (glue area) was masked off and the low end sprayed with filler/primer. Sanding this down filled any remaining seams.

Estes Semi-Scale Saturn V, Kit #K-39, Part 3, Engine Mount

Cutting the coupler a little oversize allows you to sand to fit.

On the left, one side of the coupler cut size is sanded on a block with 220 grit.

On the right, clear tape holds the ends together with a good, slip fit.

Here's the finished engine mount. 

The clear coupler is held in place between the upper two centering rings. There is no glue holding the clear coupler to the rings.

The kit didn't include and engine block, I added one.

Before cutting the fin slots, the tube seams were filled. 

These older tubes had very tight, almost invisible seams. It only took one good shot of filler/primer and sanding to fill them.

On the left, a paper towel is wrapped around a painting wand for a better fit inside the BT-60. On the right, an inside wrap of tape keeps out the filler/primer spray.

Estes Semi-Scale Saturn V, Kit #K-39, Part 2, Engine Mount

About 3/16" of the inside of the motor mount tube got a wipe of CA glue applied with a Q-tip.

Never apply CA glue where a wood glue joint will go later. Wood glue needs to soak into the surface. CA glue seals the area where it is applied.

The instructions say to cut a 1/8" square notch in a centering ring.

I used my rotary punch to cut a half circle for engine hook movement relief.

The upper ring got a slight recess cut for a better fit over the engine hook.

Instead of cutting out a 1/8" slice from the clear oversize coupler, cut a single line. Use an aluminum angle (set inside) for a straight cut line.

Slide the coupler in the BT-60 and check the overlap. Mine was a little less than 1/8" wide. Mark and cut the second line a little oversize. Final fitting in the next post.

GOTCHA: When testing the fit of the clear coupler, I found it was cut uneven. One side was longer than the other by about 1/16". If used as supplied, the third upper ring would sit at an angle when butted up against the coupler top. The long side was sanded so all sides were the same length.