Steve, how do you get the Barbie to eject from the payload area? And, that chute looks interesting...any close ups of that chute?
Craig,
Regarding the ejection, it took me long time, and multiple approaches, to arrive at what turned out to be a very simple solution. The ejection charge separates the rocket below the transition. No ejection charge enters the payload bay. The nosecone sits on the payload section very loosely and is attached with a piece of very lightweight kevlar. The nosecone is loose enough that if you turn the rocket over it just drops off. At ejection the parachute pulls on the payload section from the underside causing the payload section to tip over, the nosecone to drop off, and Barbie to slide out. Theoretically Barbie might get tangled on the nosecone kevlar line but so far it hasn't happened.
You could actually adapt this technique to any payload rocket and turn it into a kid's-toy-lofter. That Quest Payloader One would work great if you sand the nosecone shoulder so it just slips out. We have launched a number of Polly Pockets as well. A baggie with a few strings works great as a parachute for the Pollys
. My girls are a little older now but they still look at the toys in any discount aisle in terms of "Dad, that's really chuckable".
I have also read of someone who did a similar midpower rocket, without a clear payload section, called the Pinata rocket. He would fill the payload section with small candy, gather all the kids around, then launch a low flight with the candy sprinkling down from a couple hundred feet. Huge fun for the kids who get to run around and gather up the candy.
The only thing I caution anyone trying to build one of these types of rockets is to do a very good RockSim to look at weight and launch rod speed issues. You really need to understand how much payload your rocket can safely carry. At NARAM 49 I used the chucker for the night launch and sent up a bunch of light sticks on their own parachutes. I just guesstimated the weight involved, got it wrong, and ended up ejecting the payload about 20 feet above the port-a-potties (basically, I cluster-bombed the port-a-potties).
My Barbie Chucker is built very lightweight so as to be able to lift a regular Barbie (4.2 ounces
) on an Estes D or E motor. I use a 5' launch rod and don't launch in any significant wind. With a regular Barbie, especially on an E, the liftoff speed is slow so the rocket is prone to weathercocking. If there is any wind I go for a lower flight with a D, or I switch to a fake-Chinese-knockoff-dollar-store-Barbie that looks like Barbie but is actually hollow and only weighs 2 ounces
.
As for the parachute, it is actually a cheap plastic parasail kite. We were in Mexico and the vendors on the beach were selling kites which come with a Barbie-sized hollow parachutist (most were Batman or Hulk figures, but they also had some Barbie-types). They were incredibly cheap (<$2) so I bought a few. There is no way they could sell these in the States because they wouldn't pass any safety regulations. The hats on the Barbies were held on with a small nail which went through the hat and into Barbie's head. The hat had to be there because they only put enough hair on the Barbie to go around the edge of where the hat was (the center of the head is bald, LOL). You could also not launch these Barbies at a church function because, to save money, the amount of fabric they used to dress them was the absolute minimum. Very sleazy, but the parachutes are great! I can only use those parachutes when there is zero wind, though, and only with a regular Barbie since the ones that came with the chutes aren't really heavy enough to pull them open.
Anyway, hope that helps. The thing I like most about the Barbie Chucker is that it is great for teaching. It immediately grabs peoples interest, both kids and adults, but there is really a fair amount of science behind making it work successfully.
Let me know if you build something similar.
