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| Last
year (2000) when I saw that the rear ejection Estes
Sizzler was going out of production, I rushed out to my
local hobby shop to pick up one of the few remaining kits.
I liked the look of this kit, but was told by Bradley
that it was way too heavy to give decent performance on
18mm motor. I determined from the start that I would
build it to accommodate 24mm motors. I had just gotten
back into rocketry at that point, and had not yet
developed a taste for mid-power motors, but when I
finalized plans to go to the G. Harry Stine Launch in
October. I decided to go all out.
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 Here are all the parts. The G55
motor takes up a
considerable percentage of the volume
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I modified my plans to allow the motor pod
to accept the long (and expensive) G55-10 motor; also I
added an interchangeable counter weight so that rocket
weight could be optimized depending on the engine I used.
Roc-Sim predicted a maximum velocity of a Mach .9 and
altitude of over 3900 feet. This drove some other
modifications. I was concerned about the structural
integrity of an Estes kit entering transonic flight. So
replaced the balsa fins with aircraft plywood. The
construction of the stock Sizzler was already pretty
beefy, since there was an extra inner tube that went
through most of the body, which gave a lot of extra
strength to the body tube. I enhanced this by adding
balsa stringers between this inner tube and the fuselage.
I added an extra tube up front to stiffen the forward
section and provide a home for the interchangeable
counter weight. Finally, I wicked in as much CA as the
tubes would hold, then went over the exterior with
thinned epoxy
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At 3900’
apogee, I was worried about recovery. I was also
concerned that the long motor pod would build up too much
momentum as it exited the tube. So instead of a
parachute, I opted for streamers. I attached two ten foot
Loc Precision orange streamers to the motor tube. The
motor tube was attached to the rocket via a 6 foot, 1000
LB test kevlar cord. The cord was anchored to the rocket’s
plastic nose cone (This turned out to be a huge mistake).
The shock cord was folded accordion style and taped at
each fold, as each taping was broken it would absorb some
of the ejection energy. This also helped hold the cord
and streamers in place while the whole thing was being
crammed into the body.
Externally, I wanted it to look like a stock Estes
Sizzler, except perhaps to add lettering that to say
"Super Sizzler" or "Sizzler 24mm" or
some such thing. But I hadn’t found the lettering I
liked, and the paint was barely dry when it was time to
pack it for Arizona. In the process of installing the
decals, I realized that I made an error on fin sweep when
I converted to plywood. (Special thanks to our Dad who
did precision work on making those fins, even if I gave
him the wrong dimensions)
(10/15/2000) It was with great trembling that I
brought this bird out to the pad. I was sure about the
stability, but the recovery frightened me. Would it come
down too fast on the streamer, would I be able to find
it?
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3…2…1..Ignition!! The G55
shot this rocket off of the pad in an instant.
Miraculously, Mark caught it coming of the pad
sporting a flame at least 20 inches long. It went
up waaaay up. Then we held our breath.
The white rocket was hard to see against the
clear blue sky, but we caught a glimpse of the
orange streamer. Bad news, it was coming down way
too slow. Surely the shock cord had separated and
only the mount came down with the streamer.
Eventually the streamer and motor pod landed over
the launch area. As it came down the reflective
coating on the booster tube was very apparent and
was doing its job. When I recovered it. It was
clear that the kevlar ripped through the plastic
nose cone, even though I had reinforced it. But where was the rocket?
Dejectedly I went in search of it. I found the
impact crater about two hundred yards to the west.
The nose cone was buried in the ground and peeled
back like Elmer Fudd’s shotgun after Bugs
Bunny corks it. The first four inches of the body
tube were demolished but the rest of the body and
fins were fine. It can be rebuilt!!
And I did, it's
called the Fierce Bad Rabbit
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