Estes Python 4 Finished

This design reminds me of a Launch Pad kit with the forward fins and fin plate details
I couldn't figure out how to mask around the die-cut fin plates to paint the lower body light gray, so I took the easy way out and simply left the lower body white.
A good looking design and a change from a standard 3FNC.

Estes Python 4 Build, Part 14, More Stickers and Decals

As in some recent kits, the decal placement falls right where the launch lug was glued on.
I cut out a piece of copy paper to better judge the notch that will be cut in the stick on band.

The notch cut was transferred onto the sticker before it was removed from the backing sheet.

Here's the gray band set behind and around the rear lug.

A tracing of the fin was made on card stock.
Both sides of all fins get two black rectangular blocks.
The outside edges were cut into the card stock template.

Set the template against the root edge and set the sticker into the cutout area.
Flip the template to do the right side fin face.

Some decals are very small, like the "NO LIFT" decals on the upper fins.
Tweezers came in handy during placement.

Estes Python 4 Build, Part 13, Stickers!

I drew up home print decals for the worded blocks.
I'll use the stickers for the bands and squares. Because they are thicker they will add some more dimension to the model.

The face card shows the body was painted a very light gray, the reinforcement (card stock plates) are white. I couldn't see any way to mask these, the entire lower section was left white.




White bands and dark gray bands go between the strake fins.
A strip of masking tape was wrapped around the body for a guide when setting down the upper edges.

Center the stickers as best you can. They were slightly wider than the space between the fins.
After they were straight and burnished down, a sharp blade cut off the excess.

Estes Python 4 Build, Part 12, Upper Section Mask

The top section is actually an easy mask. Gray paint goes from the middle body separation up to the nose cone. The upper fins are left white.
The rear of the fins are square, the tops are even with the top of the body tube.

A long strip of Scotch tape was set around the root edges of all four upper fins.

Masking a (somewhat) wide fillet of Titebond M&TG takes a few extra moments.
I try to set the tape line down the center of the fillet.

After the gray paint was sprayed the tape was lifted.
This was one of the better recent masks. The lines are clean and sharp.

Estes Python 4 Build, Part 11, Dry Fit, Lug Gluing and White

Here's the dry fit -
This is a TALL BT-55 model, about two feet tall.
It should be a good model for the small field with a B6-4.

The two 5/8" long lugs were glued in line with a launch rod for alignment.

White coats followed.
After the first coats were set I could see the forward strakes didn't get a good enough seal against the cardstock plates.
A thin fillets of Titebond M&TG was set down and the fillet smoothed with a Q-tip.

Estes Python 4 Build, Part 10, Conduit Fix and Strake Gluing

As careful as I tried to be, there was still some glue stick on the outside surface of the conduit.
The card stock is glossy so I was able to wipe off the glue with a barely damp paper towel.

There was only one conduit corner lifting.
When using a glue stick try to get an glue overall coat, especially on the sides and corners.

A small amount of glue was scraped off the top of the glue stick.
The glue was applied under the conduit.
The lifted corner was burnished down.

The middle strake fins were dry fitted.
The trailing edge wasn't parallel with the large fin leading edge (inset).

The trailing edges of all four strake fins was sanded until it was square with the large fin.

The sanding took the edge down to the balsa and had to be refilled.







For a spacing guide, two pieces of 3/32" balsa were glued together.
This helped keep the space between the two fins consistent.

Estes Python 4 Build, Part 9, Conduit Prep & Glue

Under the long middle fins sit the flat conduits.
These are die-cut on thin, glossy card stock.



The fit couldn't be very good over the curve of the body tube.

Before gluing the conduits were pressed over a dowel to put some round onto the gluing surface.

Glue sticks are the best for this kind of adhesion.

Set down a piece of paper for a clean gluing surface.
Rub a light cover of glue on the back of the conduit.
The back is the side with the raised edges from the die cutting process.
Be sure to get glue on the sides of the conduit. The sides may want to raise up if not glued down.

Use a clean dowel to roll over the conduit.

Smooth from the center line and out to the edges.
Pick up any glue that might squeeze out the edges before it dries.

A glued conduit is ready for the long middle fin to be attached.

Estes Python 4 Build, Part 8 Fin Fitting and Fillets

Before spraying on any filler/primer:
This strips of masking tape were pushed into the fin slots and against the root edge gluing areas.
I didn't want to get any primer where the fin root edge would glue.

The primer filler was sanded down first with 220 grit.
The side of you thumb acts like a cushion and fits the round tube well.
The 220 grit removes most of the gray primer. Sanded just until you start to see the white tube.
Then switch over to 400 grit to smooth it all out.

The first fin fit wasn't good.
The root edge needed a narrow notch for the Mylar engine hook ring underneath.

Fit each fin in it's own slot.
Mark the first fin and it's slot with a "1".
All the fins will fit differently so keep track of their positions as you adjust the root edges for the best fit.

The opened tail cone slots were wider than the 3/32" thick fins.
Titebond M&TG was used to fill the open slots on either sides of the fins.
The Molding and Trim Glue worked well and didn't show any bubbles after it dried.

Estes Python 4 Build, Part 6, Balsa and Lug Prep

There's a tight corner on the upper fins, right where the breaks happened earlier.
I dropped a little more CWF in the tight corner than normal. It might end up a little rounded after sanding.

Sandpaper was folded and most of the CWF was taken off.
Sand carefully, you don't want to break these.

Here's all the fins taped down on cardboard for a shot of primer/filler.

Notice I've taped the fins down with all the root edges facing away.
When sprayed from this angle, this will help keep the primer off the root edges. Less sanding and a better glue joint.

The launch lug is cut in two.
After filling with CWF and sanding, set the lug over a dowel for cutting.
If you try to cut a lug without support inside, chances are it'll be crushed.

Estes Python 4 Build, Part 5, Gluing the Engine Mount

A ring of glue was rolled in the rear tube using a marked dowel.

Apply a ring of glue around the dowel end.
Set the dowel into the tube up to the pencil line on the dowel.
Roll the glue into a bead all the way around the inside of the tube.

The tail cone is used to press the engine mount into place.
You aren't gluing the tail cone in yet. When the tube end is even with the tail cone remove it.

The centering rings were a little loose.
I wanted to let the mount dry with the tube sitting upright.
To make sure the mount didn't slide down a piece of tape held the mount up.

There only glue holding the mount is above the upper ring.

A fillet was applied to the inside and lower ring joint with a Q-tip.

The tail cone was glued in using plastic cement.

The engine hook is centered between two fins and in line with the launch lug.

Estes Python 4 Build, Part 4, Plastic Parts Prep

The tail cone was cut from the adapter section.
The raised fin slots are cut off like the previous Paveway build and the current Estes V2 model.

A possible problem -
The fin slots are wider than the 3/32" thick fins.

The smaller end of the tail cone was rounded out using 220 grit around the supplied yellow spacer tube.

Jumping ahead:
I installed the clay weight in the nose cone.
Instead of rolling the clay into a snake,
It's easier to roll it into small balls.

With the clay rolled into balls it settles more evenly in the tip of the nose cone. You're not chasing and tamping the clay "snake" around the inside of the nose cone.

Estes Python 4 Build, Part 3, Fin Prep

Be ready - 
As careful as I could be removing the pieces from the die-cut sheet, the upper fins broke right down the balsa grain.

The broken halves were set on a straightedge and glued using medium CA.

The long middle strip fins were stacked and gang sanded.
After lining up the fins at the bottom you can see how the tops didn't match up.

Estes Python 4 Build, Part 2, Engine Mount

The engine mount didn't end up looking like the instruction drawing!
Compare the drawing on the lower right with the finished mount shown below.

I ended up adding 135 lb. Kevlar to the mount instead of using the tri-fold for the enclosed short shock cord.
Estes included elastic shock cords in these kits.
The shock cord was only 18" long.
This model breaks at the middle and would use two tri-fold mounts.
After tying a loop in the center of the shock cord for the parachute attachment, the kit supplied shock cord would be less than 12" long!