Estes Star Seeker BT-50 Upscale (Tri-Pack) Kit #0866, Part 1, Parts

After building an interesting BT-5 clone,

this one begs for an upscale. 

There are enough differences to make a larger model interesting.

Mentioned in the previous build, this isn't a 2X build. 

All original kit piece sizes will by multiplied by a factor of 1.8 to get the BT-50 sizes.

I'll be using 13mm motors. I made some 5/50 cardstock centering rings a few weeks back. We'll use them on this build.

In the picture above, the 1/4" lug "jets" tubes and "gun" dowels were cut at the same time as the previous BT-5 based build. They were also cut short. I recut both at the longer, correct length.

The Big Fix!

I had broken a fin or two at the last launch.

To glue these back, I needed a small clamp that wouldn't dent the balsa.

Previously, I had adapted some small clamps from clothes pins. 

Notice the regular clothes pin on the left. The wooden halves have been flipped on the right.

For a better explanation: CLICK HERE

The glue line shows the unusual break.

Normally I'll clean off the glue before applying the clamps. I left the glue line for the picture.

Be sure the squeezed out glue is cleaned off where the clamps sit or you might glue the clamps to the fin!

After the glue dries and the clamps are removed - 

I hit any breaks with a Sharpie pen.

Ready for flight.

Estes Star Seeker (Tri-Pack) Kit #0866, Finished

Big graphic decals on a very small model!

Notice how close the door is to the base of the nose cone.

Not much to see on the underside.

For such a small rocket, it's an interesting design.

It begs for an upscale. That is coming . . .

Estes Star Seeker (Tri-Pack) Kit #0866, Part 9, Decals

After the door/windows decal has dried,

Cut through at the nose cone joint with a new razor blade.

I don't normally use Future clear coats. I find it unnecessary.

It will hold down an exposed edge that could be subject to peeling back.

On the left, a Q-tip was used as a brush to seal the decal on the leading edges.

On the right, another decal where the edge ends at the body tube.

The Kevlar was tied to the elastic shock cord using a simple overhand knot.

I'll trim off some of that excess.

In the comments I was warned about how easily the fins will break off on a hard landing. There's not much of a root edge to glue onto the body tube.

I decided to slow the descent with a streamer.

It'll probably still break off, but I gave it a try.

The body tube is short, but I could fit in the wadding, streamer and nose cone!

Launch! R.O.A.R. Monthly, February 23, 2025

For a change, I went to the R.O.A.R. launch in Christmas, FL. ROAR has one of the most sophisticated pre-launch procedures I have ever seen. 

There is a four pad low power rack and a mid power rail launcher.

Many Blue Origin families and first timers today. It took a while for the pads to clear so the "old timers" could launch.   

I had the first rocket in the air today.

A favorite, the Quest FLV with an Estes C6-5. Estimated altitude was 500 feet.

Stable, clean with touchdown close to the pad.

Next up was the New Way ALIEN INVADER with a B6-4.

This is one of the square tube models from New Way.

Estimated altitude was 350'.

One broken and separated fin on landing.

Flight of the day goes to Gary Dahlke.

An Honest John with a G79-4. The loud motor surprised the first timers.

A chute release was set for 300'. 

The Florida Tech Design Group brought their Doordash D.A.R.T.

Dart stands for Demonstrator for Autonomous Rapid Transport.

Today was a "boost" test using a G25 motor. In future flights, they hope to land it much like a Space X booster. The landing legs are retracted here.

Next up was the Estes EAC FIRE CAT clone with a B6-4

Altitude was estimated at 300'.

I usually expect to break a fin on this one, but it touched down without damage.

Here's the Odd'l Rockets F-18 in the Blue Angels decal livery.

I should have used a B6-4, but had an anemic A8-3 loaded.

The rocket launch was a "loft", maxing out at 200 feet.

No damage on recovery.

The Estes STAR SEEKER clone (now being built on this blog) had a first launch with a 1/2A3-2t motor.

Fast and high for a 1/2A engine, probably reaching 225 feet.

Good thing I added a streamer! You'll need one to find it as it falls.

I was warned - a fin did break off when it hit the ground.

To finish the day, I did launch a MMX Fliskits CRAYON. It was a big hit with the kids.

I would guess it got to 100'. It needed lots of eyes on it and a few helped find it in the low weeds.

Six up, six recovered, two with broken and fixable fins.

Estes Star Seeker (Tri-Pack) Kit #0866, Part 8, Decals

I'm making the decals available to Patreon subscribers.

Both the BT-5 and BT-50 sizes will be on a home print PDF.

To get a canopy decal to fit around a nose cone, 

Cut with a rounded relief in the center for a some flexibility. 

Note: Rounded. Sharp corners can lead to tears of the decal film.

After the canopy was in place - 

The door and window decals were transferred. 

The nose cone body tube joint will be cut after the decals dry.

Enlarge the picture to see the wing reflection centered down the windows. 

This can happen with home print decals - 

The blue in the wing decal started to break up. This is usually caused by too many tries at repositioning. 

The decal sheet has two sets for the BT-5 size model.

There is some overhang on the outside edge.

After the decals dry, you can slit and remove the excess using a sharp razor blade.

Estes Star Seeker (Tri-Pack) Kit #0866, Part 7, Paint & More Sanding

Here's the launch lug that will slide over the launch rod.

The rear of the lug is 5/8" from the rear.

After spraying the the model with gloss white,

some fillet bubbles showed. These were filled with more glue.

After the paint dried, the launch lugs showed how rough they were. 

This required some 400 grit sanding before another coat of spray.

No masking!

Just a clean, glossy white finish, ready for decals.

Estes Star Seeker (Tri-Pack) Kit #0866, Part 6, Fin Assemblies

Keep your glue lines short - 

Set the lugs in place and make the fin edges with pencil. 

Apply some glue up to the pencil lines and place the lugs.

Here's how the lugs set when set against the fin joint.  

The wing fin assemblies are glued to a standard 120 degree three fin spacing, using just two of the pencil lines. This makes a wide "W" shape.

The "flight" launch lug is glued onto the third pencil line.

Estes Star Seeker (Tri-Pack) Kit #0866, Part 5, Fin & Launch Lug Assemblies

The dowels are glued to the top of the upper (unmarked) fins.

Two launch lugs are glued side by side.

Make two sets. I found it easier to make glue fillets now.

On the left, I've lightly sanded the glue line for better glue adhesion. 

On the right, the dowel fins are glued with that spacing overhang on the outside.

Be sure to make two "mirrored" fins.  

Estes Star Seeker (Tri-Pack) Kit #0866, Part 4, Engine Block & Kevlar ShockCord

The original kit had two engine blocks,

one for the engine stop, the second to tie a rubber shock cord. No parachute or streamer, just nose-blow recovery.

Enlarge the picture on the left.

I can't imagine trying to slide in that upper block ring into a ring of glue with a binding rubber shock cord tied around it.

I'll be installing a single lower engine block with a tied on Kevlar line.

The engine block got a notch for a better fit of the Kevlar line tie.

The inside 1/8" (or so) of the tube got a wipe of CA glue. This was followed by sanding just the edge with 400 grit on a block.

I used a spent "T" motor to position the engine block and Kevlar line.

Occasionally your find a raised cut-off burr on the end of the casing. Roll that off with some 400 grit.

This makes for an easier slide into the engine mount tube.

TIP: When installing an engine block, have ALL your parts close at hand. You don't want to be looking for the engine block as the glue in the tube is starting to set.

The glue applying dowel is marked with a pencil ring about 1 1/2" from the top. 

A ring of glue is set around the top of the dowel.

Set the dowel in the tube up to the pencil line trying not to touch the inside walls of the tube. 

Roll the dowel and transfer a line of glue around the inside of the tube.

Quickly set in the engine block and push into position, with 1/4" of the engine casing extended out the bottom of the tube. Remove the casing.

Estes Star Seeker (Tri-Pack) Kit #0866, Part 3, Filling Seams & Gluing On Dowels

The body tube, dowels and launch lugs were CWF filled and sanded.

A dowel was slipped in for support while sanding.

A shot of filler/primer followed .

Here I'm sanding the filler/primer to surface with an old piece of 400 grit. Any filler/primer that might collect on the sandpaper can be cleaned off under running water with a soft brass wire brush.

Two of the four fins are marked 1" down from the top edge.

This is where the perpendicular fins will be glued on.

I found it easier to mark a 1" span on a scrap piece of cardboard, then set the fins on the pencil lines.

Here's the first try at the 1" long dowels.

Looking at the instruction drawings, I could tell they were too short. There are no launch lug or dowel lengths listed in the instruction parts list.

Here's the longer 1 1/4" dowels.

I now have the feeling the dowels should be a smaller diameter. Oh well, I'm going with what I've cut.

(Edit: The dowel diameter I used was 3/32" diameter)

Estes Star Seeker (Tri-Pack) Kit #0866, Part 2, Parts Prep

The Star Seeker fins are the 4 parallelogram shapes, fourth row down from the top.

Cut out four from 1/16" thick balsa.

Before the launch lugs were cut to length, 

I filled the seams with CWF. The long lug was held by pushing it onto a Q-tip.

There is a slight flared lip on the shoulder of the nose cone.

Roll down the lip with some 400 grit.

The balsa fins, dowels and launch lugs were filled with CWF and sanded with 400 grit.

All were taped down for a shot of filler/primer.

These are the first, incorrect length dowels and launch lugs. In the end, all were re-cut to 1 1/4" long.

Estes Star Seeker (Tri-Pack) Kit #0866, Part 1, Parts

 

The dowels and launch lugs (shown above) were cut too short. The build will show the longer and correct 1 1/4" long lugs and dowel pieces. Mistakes can happen when lengths aren't listed in the instructions. I took a guess by simply looking at the instruction drawings.

You might assume a BT-5 is 1/2" diameter and the BT-50 at 1" diameter. That would mean a simple 2x upscale. But, the BT-5 is actually .541" diameter and the BT-50 is .976" diameter - Not a 2x upscale.

I'll be building a original BT-5 version and after that an upscale BT-50 version.

To see Jay Goemmer's "Downscale Chart: CLICK HERE

While Jay's chart says to multiply by 1.79, I'll be using a heavy walled (and slightly wider diameter) BT-50H tube.

Here's my conversion chart. Every dimension of the BT-5 parts was multiplied by a factor of 1.8 to get at the BT-50H sizes.

I drew up decals for both the BT-5 and BT-50 version.

The rounded corner "door" rectangle will be fixed with a narrower line.

Gotta' love a model where the parts fit into a 3" x 5" zip bag.