|
| |
Inspector Gadget
|
This rocket was built almost as an afterthought. A
mailing tube, some G10, a little fiberglass, and a nose cone later,
Inspector Gadget was born. I had always wanted a 3" rocket
for 54mm motors, and the cheap, strong 3" mailing tubes available
at Staples seemed to be the perfect starting place for a rocket.
Keep reading to see how to build a strong rocket on the cheap. |
|
| Flight
Log |
Flight
Details |
Construction
and Modifications |
RockSim
File |
Flight #
|
Motor
|
Electronics
|
Performance
|
Comments
|
| 1 |
J285 |
N/A |
N/A |
Perfect first flight with motor ejection. |
| 2 |
J275W |
ARTS |
6225 ft / 745.34 fps / 13.25 gees |
Great white lightning ride. Invisible at
drogue deployment, later spotted under main chute. Perfect
recovery. |
Flight #2, August 2004
| Well, after the nice first flight, I resolved to get
Inspector Gadget in the air again. As with all my other projects,
various conditions popped up that prevented this from happening. I
finally resolved to fly IG again at the August 2004 launch, whether the
weather was good or not (wow, that sounds kinda weird). I loaded it
up the night before with the ARTS (hoping for a flawless performance to
clear its name) and a J275W. We headed out to the range early, and
after putting up the Quasar, I loaded IG onto the rail. I walked
back, Rick O'Neill counted down, and hit the button. IG took a
moment to pressurize, then instantly lifted off the rail arrow-straight,
heading for the sky. After burnout, I completely lost track of the
(relatively thin) tracking smoke against the cloudy sky. We all
heard a pop, indicating that I either had a drogue chute or I had kicked
the casing and the vehicle was coming in ballistic. A quick glance
out to the range confirmed that it was the former of the two -- my dad was
tracking the bird with binoculars, and was still looking up after a long
while. Eventually, IG returned to 777 feet (I thought it was a funny
number when I programmed the ARTS... go figure) and deployed the SkyAngle
main chute right on time. Beautiful flight and recovery, just a
short distance away. I can't wait to try it with a J415! |
Liftoff
Cleared the rail
|
Heading for the sky
Safe recovery
|
Flight #1, December 2003
| I decided to put up Inspector Gadget on a Pro38 J285 for its first
flight. According to RockSim, this should be a nice, slow flight
to almost 6000 feet. Originally, I planned to fly the rocket with
its full dual deploy configuration, 18" drogue, and R7C main.
However, as various conditions prevented that plan from happening, I
decided to fly it with just motor ejection. The waiver was running
out and I had to get Inspector Gadget ready quickly to get it off the
ground. I switched to a PML 36" chute because the R7C was
putting up a fight to be repacked into the booster. I trotted out
to the pad for the next-to-the-last flight of the day. LCO John
Van Norman launched the rocket almost immediately after I returned to
the rangehead. Inspector Gadget lifted off slowly, weathercocked a
little to the left, and soared into the air. After burnout, the
rocket kept coasting, and coasting, and coasting for the full 15-second
Cesaroni delay, tracing a white line in one of the numerous blue holes
in the sky. Finally, the chute popped just as the rocket passed
apogee, and Inspector Gadget rode down nice and slow, landing about 1/2
mile away. A perfect first flight, albeit with single
deployment. I'm gonna put her up again soon with more power! |
Prepping for a late afternoon flight.
Beautiful liftoff on the J285.
|
Still climbing...
Successful recovery!
|
Design and Construction
|
|
Construction
I wanted this rocket to be built for very little money,
using some parts I had on hand. I went down to the local Staples
and picked up the airframe tubing -- $1.50 for 2 tubes. This stuff
was strong as it was, but I added a wrap of 6 oz. glass to protect it
from landing damage and the occasional K1100T. The fins were cut
from a 12 x 12 sheet of 0.093" G10 that I had picked up from the
Bolzitars at LDRS. I beveled the fins on my fin beveling jig (from
John Coker) and then attached them to a scrap piece of 54mm phenolic
that I was using for a motor tube. I cut 3 centering rings from
some leftover 1/4" plywood using my fly cutter and a hole
saw. The coupler for the electronics bay was made by slicing a
piece of the same tubing down the side and glassing the inside.
Bulkheads were made using the fly cutter and some more of the same
plywood. A shock cord mount was fabricated using a piece of
1/8" KevCord (from West Marine) knotted around the motor mount,
then frayed and glassed onto the tubing. A PML nose cone rides on
top, and an R7C chute is used as the main. The rocket comes in
with an 18" drogue from apogee and deploys the main chute at 500 feet via an RRC2.
Alternatively, the vehicle can be flown in single deployment
configuration using a PML 36" chute. A couple coats of Smooth Prime, some white primer, and the rocket was
painted grey and black.
Conclusion
This rocket is great to have around. It not only
looks good, flies just as well, and it was cheap (my favorite part
<g>). It's going to be a great heavy-weather flyer, and the strong
construction means the rocket will last a long time.
|
|
|
