Interceptor MKII Heavy
I have always loved the Estes Interceptor, they really knocked it out of the park with the design.
Here's a BT-60 29mm powered version that has design cues based on the
original. Pods are reversed, decals are flipped. It's not a clone..
well... sort of.
2025-07-01 Nose Cone Turning
Turned the Nose Cone from a piece of 4 x 4 Pine, and the Cockpit from a 1" Dowel.
Updated the OR Simulation to match the as-turned piece.
Gluing the Nose Cone
Gluing the cockpit to the nose cone.
I've
also learned that when the nose cone has a thin shoulder its a good
idea to glue a coupler or a body tube into it. The thin shoulder can
crack, the glued in coupler helps to prevent that.
2025-07-02 Fabricating Fins and Modifying Nose Cone
Cut the Fins from 1/4" Plywood and then sanded them to shape. Routed the edges with a 1/8" Rounding Bit.
Chucked the Nose Cone up in my lathe and tapered the front section down.
Gluing the Spears to the Vertical Stabilizers
Cut some 1/4" dia Poplar dowels to length, then sharpened them with a pencil sharpener.
Glued
them to the Vertical Stabilizers using Gorilla Wood Glue. I noticed
the spears weren't parallel with the bases, so I sanded the base down on
my belt sander to make them parallel.
2025-07-03 Gluing The Fins.. Day 01
Using multiple fixtures to align the
fins... I started with one, then went to the other. There really is no
substitute for a good flat piece of plywood, with a cut-out for the
body tube. Not real hi-tech... but it works very well.
2025-07-04 Gluing The Fins.. Day 02
Unclamped the rocket from the fin alignment plywood board. The Main Wings alignment came out nicely.
Time to install the (2) Vertical Stabilizers
So
my fin alignment fixture has been relegated to holding the rocket while
it dries.... I'm using the tried and true method of eye balling fin
alignment for the Vertical Stabilizers.
The
C-60 was marked with the fin locations using the wrap around template
provided by OpenRocket. Wood glue is applied to the root chord of the
1st Vertical Stabilizer and then the fin is set in place onto the C-60
and held for about 30 seconds. Since the fins are made of plywood its
easy to align the center ply with the pencil mark on the C-60. That's
enough time for the glue to bite into the C-60, at which point it's set
on the fixture for half an hour to dry.
The gluing procedure is repeated for the 2nd Vertical Stabilizer.
The
rocket fins were then measured from Wing Tip to Vertical Stabilizer
Tip. Measured distance varied by 3/16". I used masking tape and
wrapped the fins from the Wing Tip up over the 1st Vertical Stabilizer,
to the 2nd Vertical Stabilizer. I then moved the 2nd Vertical
Stabilizer Tip to match the 1st Vertical Stabilizer Tip measurement. I
then used another piece of masking tape from Wing Tip to the 2nd
Vertical Stabilizer.
I'll let this dry 24 hours.
Ventral Fins and Wing Pods
Wing Pod Fit-Up
I used masking tape and a couple
toothpicks to fit-up the Wing Pods to the Wings. I then used Gorilla
Wood Glue to tack them into place.
2025-07-05 Glamour Shots
Installing the BT-60 Sections
Marked the front section of BT-60 tubing and then cut the slots for the
Wings, Ventral Fins and Vertical Stabilizers. Applied a generous
coating of Elmer's White Glue to the C-60 and slid the BT-60 into place.
I then used a bunch of spring clamps and tape to hold everything in
place while the glue dries.
Once that dried for 5 hours the lower C-60 was cut, glued and fitted.
2025-07-06 Fin Q&T Fillets and Spool
Made good progress today on the Fin
Titebond Quick and Thick Fillets. Also cut the Spool parts and started
gluing them together.
2025-07-08 Still working on the Motor Spool...
Gluing / fireproofing the Internal Bulkhead / Pine Dowel / Motor Tube with Gorilla Wood Glue.
The black plastic stir sticks are just temporary and will be removed when the glue is dry.
2025-07-09 Nose Ballast and Launch Lugs
I ended up boring the Nose Cone out for a 1" dia x 1-1/2" piece of steel Ballast.
Inserted the Ballast into the Nose Cone... and then glued it in place with Gorilla Wood Glue.
Cut the (2) Launch Lugs and began gluing them to the Fuselage and Wings.
2025-07-10
Cha... Cha... Cha.... Changes
How can I glue the Nose Cone to the Body
Tube, yet still stow the Altimeter in the Nose Cone? The Recovery Dowel
is in the way... but what if I make the Recovery Dowel removable?
I'm
using a stainless T-Nut, and a 1/4-20 Stud. The T-Nut is retained on
the outside of the BT/C-60 by a wood glued custom turned Disc made from
1/4" plywood, and the inside of the C-60 will be soaked with CA.
The opposite end of the 1/4-20 Stud is held solid by a piece of 1/4" plywood that is glued to the inside of the C-60.
The
bolt shown in the photo is holding everything in alignment while
gluing. After the glue has dried the bolt will be removed, a section
of the threaded portion will be removed, the hex head will be cut off,
and a slot will be cut into the shank to allow for installation using a
screw driver.
2025-07-11 Tail Cone and Recovery T-Nut Pod
Turned the Tail Cone on my lathe and it
of course broke... which I pretty much figured it would. I glued it to
the Spool and I'll finish it tomorrow.
Also took a Dremel with a cut-off wheel and trimmed the sides of the T-Nut / Plywood Cap to about 1/2" wide.
2025-07-12 Turned the Tail Cone and cut the Hex Head off the Recovery Dowel.
Then... took her out for a swing test.
Those Antenna... ain't hell-for-stout... they are coming off, and being
replaced. Every time I work on the rocket they're pointing in a
different direction.
Clamped a piece of
scrap steel to the Vert. Stabilizer and used a Dremel with a cut-off
wheel to trim off 1/4" from the tip of the fin, then repeated that for
the other fin. Used 100 grit sandpaper on the cut to remove the burned
edge.
Cut two 4-1/2" x 1/4 dia dowels and sharpened them with a pencil sharpener.
Used Gorilla Wood Glue to install the Antennas onto the Vert. Stabilizers.
