
(Contributed - by Bill Eichelberger
- 11/15/02)
Brief:
The Estes Astron Invader is one of the least seen, yet also one of the most
interesting rockets produced by Estes in the early years of their existence.
Available only from 1965 to 1967, the Invader may have had the distinction of
being the first of the early kits to have its production run canceled.
Despite this, and in some ways because of it, the Invader is one of the most
uniquely challenging cloning projects from the early days of organized
rocketry.
Construction:
- 1/8" balsa sheet
- 3/32" balsa sheet
- BNC-20B (available from Balsa Machining Services)
- BT-20J body tube (2.75")
- Nose weight
- Launch lug
One nice thing about cloning the Astron Invader is that it is a project
that can be started, finished and flown over the course of a weekend. The
limited number of parts and finish options combined with the excellence of the
original plans (downloaded from JimZs site) make for a quick, relatively
fool-proof build. I only deviated from the instructions in the installation of
the nose weight. Estes no longer makes the old lead nose weights and I turned
the house upside down trying to find a suitable replacement. Just as I was
about to give up I noticed a magnet (the type used in place of pins to hold on
name tags, lapel pins, etc.) hanging on the refrigerator. I glued it directly
to the rear of the nose cone with thick CA and to my great surprise, it
actually worked. The glide wasnt perfect, but for a starting point it
wasnt bad.
Finishing:
This is where I made my mistake. I made three flights with my Invader, all of
them entertaining. While the flight pattern wasnt terribly smooth, it
also wasnt the disaster that I was privately sure it would be. From this
initial success I got cocky. I thought the rocket would look good with a light
coat of metallic silver paint before it made its QUARK debut that
following Saturday. Then, since the silver rubbed off on everything, I followed
with a light coat of semi-gloss. Surely the little bit of weight added by the
paint couldnt hurt, right? Hugely wrong. Read on.
Construction Rating:
4
out of 5
Flight:
I awoke one blistering hot day this summer to find the house unexpectedly
empty. With my son spending the day at an amusement park and my wife and
daughter on an outlet shopping binge, I was free to do as I pleased. Despite
the heat, I chose to head up to quasi-legendary B6-4 Field to launch a few of
the projects that I had been working on. The unpainted Invader was first on
this list. Armed with two packs of the newly re-introduced 1/2A6-2s that
I had bought especially for the occasion, I gave the Invader first flight
honors. It didnt disappoint. It did a surprisingly quick, tight loop off
the pad, coasted upside down through the delay period, then returned to right
side up after the surprisingly loud ejection charge. It settled into a steep,
short, fluttering glide and came to a rest in the only green spot remaining on
the field at that point in the summer. (The drainage ditch, thankfully dry.)
For the second flight I added a small bit of clay to the nose and chose an
A8-3, hoping for a little more height and maybe a better glide. I got more than
I bargained for. The Invader left the pad far more quickly and immediately
began doing a series of acrobatic loops, not unlike a sideways figure
8, before settling into a slightly slower, less steep glide. I added more
clay for flight #3 and went back to the 1/2A6-2. Though still a low, tight
loop, the glide was noticeably improved with the Invader gliding for close to
50 feet after the ejection. That settled it. I was ready to spring it on my
fellow QUARKers.
But first, a classy silver paint job!
Needless to say, flight #4 pranged badly 15 feet from the pad, shattering
both of the pylons that connected the motor tube to the body. Literally. When I
tried to repair the Invader later, chunks of balsa came off of the shredded
pylons as I attempted to sand them back into flyable shape. Clearly I had
erred, and now I needed to try some somewhat hesitant repairs. I replaced the
shattered pylons and sanded off as much of the offending paint as I could. This
seemed to be surprisingly adequate and the Invader made several additional
successful flights before destroying itself by power-pranging the one electric
line at the Summit County Fairgrounds in NE Ohio on Labor Day weekend. With no
adequate method to fix the damaged balsa without replacing most of one wing, I
decided to retire my first Astron Invader to the balsa bone yard and try again
at a later date.
Flight Rating:
4
½ out of 5
Summary:
As I said earlier, the Astron Invader is a great project if you are short on
time before your next launch, but still want to show up at the pad with
something new. Youll undoubtedly get a lot of puzzled Whats
that? due to the short shelf life of the original, but it is almost
guaranteed to be the only one on the flight line. Depending on your building
and trimming skills, you might also wind up with a lot of What was
that? as you carry the remaining scraps of balsa to the resurrection
pile.
PROs:
Seldom seen classic?
Overall sense of Whats next?
Quick build
Oddball looks
CONs:
Trimming difficulty and overall sensitivity
Estes no longer sells nose weights
Overall Rating:
4
½ out of 5
Recommended Motors: 1/2A6-2, A8-3, B4-2, B4-4