Lets fly some Candy Rockets!
 Begining
The Piñata Rocket began at the monthly LUNAR launch in October
1999, after my daughter, Krystal, was born that September 23. I don’t
smoke, so I gave out candy in lieu of cigars. I bought 60 "It’s
a girl!" suckers from Sees Candies to distribute to my rocket
friends. But just handing them out wasn’t my style, so I needed
an unusual way to give them out. In a moment of brilliance I decided
to drop them from a rocket, but a falling sucker might be kind of
painful so I attached a streamer to each sucker. At the time, the
only rocket I had for lofting candy was a North Coast Rocketry Phantom
4000. I honestly didn’t expect the kind of response I got from
the kids, they went wild chasing down all the suckers. The next month,
my son Kevon wanted to join into the fun and fly candy for the kids.
This is when I realized how much the kids liked it.We did a repeat
flight at the LUNAR November launch 1999. At this point I knew I needed
a better candy-deploying machine.
Step Two
About that time, Aerotech came out with the G-Force.
It seemed to have every thing I needed: a 4" airframe and a large
upper section that could easily be turned into a payload section,
so the G-Force
went on my Christmas list. It took until February 2000, before the
G-Force actually shipped, but I got it built in time for the March
2000 launch. I built the G-Force essentially stock including using
CA (cyanoacrylate or super glue) rather than epoxy for most of the
joints. I was a little concerned about CA holding up to the stresses
of H motors and all the candy I could pack into the rocket, so I used
epoxy on the fore and aft centering rings. To fly this rocket on H
motors meant that I had to leave out the motor block and motor hook.
I used three 8-32 studs, epoxied along the motor mount tube, for motor
retention. The next modification was that I didn’t glue the
nose cone on. Instead I ordered an extra parachute, added an eyebolt
through the bulkhead of the payload section, and tied on a shock cord
from the eyebolt to the nose cone. The grand plan was to use motor
ejection to pop the drogue parachute, and then hope that gravity would
pull the nose cone off, deploy the candy and the main parachute, and
bring it safely back to earth. During the first launch in March, that
is exactly what happened. I was tickled and the kids loved it!
Discovering the Bugs
The next flight, though, was April. I decided that an Easter theme
was in order. I made little parachutes for about 40 little plastic
candy filled eggs. This time, though, the payload section drag separated
at main engine burnout due to the high drag of a 4" body tube
trying to slice through the air. The M&M filled Easter eggs slammed
upwards into the back of the nose cone which pushed the nose cone
off. Those heavy little Easter eggs were deployed into a 150mph air
stream. Needless to say, scotch magic tape wasn’t so magical
and failed to hold the little eggs to the parachutes. Fortunately
though, the kids saw the parachutes drift off with the wind. As they
ran for the parachutes, little “eggrenades” started exploding
on the ground where the kids were. Thankfully, not a single person
was hit by falling eggs. It was kind of comical to see the explosion
of M&Ms erupt from the ground where the eggs impacted. It reminded
me of the Skittles rainbow commercials.
Trying to Fix the Bugs
Next launch I tightened up
the nose cone so it would not drag separate. It didn’t work.
Three launches in a row the nose cone drag separated spitting candy
upward
at 150mph.
I finally did get the nosecone the
correct tightness for gravity to pull the nose cone off. I remained
concerned, though, that one time the nose might not pull off and then
a 6 pound, 5 foot tall, 4 inch rocket was going to come back to Earth
under one parachute.
A New Plan
It was nearing Christmas again,
so I put a BlackSky AltAcc2A altimeter on my Christmas list. The night
before the December 2000 launch, my
wife, Sheryl, gave me my present a little early. I was up late that
night reading directions and trying to get the AltAcc into the rocket,
but I could not get it to pass the ground test. Being scared I flew
the G-Force with the motor as primary deployment and the AltAcc as
backup. My fears were unfounded. The AltAcc worked perfectly. The
motor ejection charge went off, the AltAcc detected parachute deployment
and apogee and it fired the drogue ejection charge. Gravity had already
the deployed candy but at 500 feet on the way down I could see the
AltAcc fire the drogue parachute charge.
Gaining Faith
Next launch I picked
a longer motor delay. This made the motor ejection charge a backup
and
allowed
the
AltAcc to act as primary
drogue deployment
device. I also tightened the nose cone so it would not gravity separate.
Perfection had been achieved. At apogee the drogue chute ejected on
time, the motor backup charge could be seen firing and then the main
parachute with the candy deployed at 500 feet.
New Bugs Revealed
Next launch I ran into difficulty
when the drogue chute separated from the booster section. Luckily,
it had
a
nice tumble
recovery and
the AltAcc still deploy the candy right on cue. I tied the two ends
of the shock cord back together and sent it up for a second flight.
Again the shock cord failed, but the AltAcc saved the payload section
of the rocket. The booster forward end was crumpled and 3" had
to be cut off. This is when I invested in Kevlar cord from Pratt Hobbies
and replaced the shock cord before the next launch. The booster was
now too short for the payload coupler to fit in. I ordered another
18" body section and two body tube couplers. From all the landings,
the tail was getting pretty badly damaged. One coupler was used to
lengthened the Piñata Rocket and the second coupler was added
inside the tail of the rocket to reduce the crumpling during landing.
Shaken Faith
The next flight of the Piñata
Rocket resulted in its first failure of the AltAcc. For whatever reason
the
drogue
igniter
did
not fire. Fortunately the motor backup still fired and the AltAcc
main fired so both parachutes made it out and another safe recovery.
Kids loved all the candy they were getting. I used the exact same
ejection charge in the same place the very next flight and it fired.
Every flight since has been perfect. It’s still a mystery why
it didn’t fire the first time.
Aerotech Fire
The next problem came about because
of the Aerotech fire in 2001 causing 29mm H motors to get very scarce.
I
bought a
Pro 38 but learned
that
it’s kind of difficult to get a 38mm motor up a 29mm motor tube.
I took a creative approach and built a 38mm to 29mm adapter. Yes,
that’s right; it adapts a smaller motor mount tube to a larger
motor that hangs about 10 inches out the bottom of the rocket. I flew
it on a Pro38 H110 with 310 NSec total impulse. It was the biggest “H” I’d
flown at the time. It put the Piñata Rocket up 1300 feet. The
kids enjoyed a lengthy amount of time anticipating the candy deployment
as the rocket drifted from apogee to 500'. It was thrilling watching
the rocket get closer to ground and seeing all the candy come out.
38mm Upgrade
Time has marched on and the Piñata
rocket has continued to evolve. I only flew the Piñata rocket
once on the 38mm to 29mm adapter when I bought a new G-Force with
an extra
body tube.
When
it arrived I threw away the stock motor mount tube and replaced it
with a LOC 38mm tube I had. I trimmed the Aerotech fins to allow for
the 38mm motor mount and cut up the fin lock system so it would fit
a 38mm motor mount. I also bought a G-Wiz LC400. The Piñata
has now become drag racing Piñatas.
Drag Racing Piñatas
The first flight of dueling
Piñatas
was at LUNAR’s Robertson
Park launch site. It was Easter again and with the two Piñatas,
I had room for 6 dozen M&M filled Easter eggs. This time with
the altimeters in place, both Piñatas deployed dozens of parachuting
Easter Eggs at low speed. The Easter Bunny’s job just got a
little easier and a heck of a lot more fun.
Today
For over five years now, every month that weather
and scheduling has permitted, candy has rained down from a LUNAR launch.
Our field
has
been encroached on by houses, which keeps me from flying at Robertson
Park any more, but during the winter at Snow Ranch, look for the Piñatas
in the sky. If you happen to be attending LDRS24 in Lethbridge Canada,
be sure to look for the Piñata rockets from LUNAR! They are
expected to be a featured event about 1 PM each of the commercial
flying days, July 14 - 17.
What's Next
I'm getting the itch to design a new Piñata rocket.
I'm currently looking a more lift capacity in a single rocket. I'm looking
real hard at a LOC HyperLOC 1600. But I also want to play with Staging
and Clustering composit motors with the G-Wiz LC 400.
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