About
One day, while walking through Wally-World (a sophisticated name for Wal-Mart), I happened upon a 3-pack of model rocket engines. I quickly searched through a pile on the shelf, but all I could find were puny A3-2 and C6-5 engines. Reading the back of the package, I saw that the C6-5s were far more superior, so I obviously bought those. The C6-5s had 4xs more total power, 3 Newtons more thrust, and a 3 second longer delay between the thrust phase and the ejection charge. I took them home, and they sat in my room for about a week. Finally, I came up with this idea for my first homemade rocket:
I used these parts:
- X1 C6-5 model rocket engine (trust me, I would have went way bigger if I could)
- X1 model rocket engine igniter (in the package with the engines)
- X1 sheet of model rocket recovery wadding (in the package with the engines)
- X2 12-gram CO2 cartridges (EMPTY – in case you were wondering)
- X1 coffee stirring straw (1 holed, not 2)
- X1 piece of paperboard or notebook cover
I used these tools:
- handy-dandy Dremel tool with a metal cutting head (you might find something easier)
- scissors
- tape (that shiny, heat-proof kind you find at hardware stores would’ve worked nicely, if I had it)
- super glue
- long-nosed pliers
- pencil (optional)
- ruler (optional)
Yeah, nothing you don’t already have or couldn’t get for cheap.
Step 1:
First, I used my Dremel tool to cut just above the rounded bottom of one CO2 cartridge, and ground off the leftover seal on the nozzle. Don’t grind off the nozzle itself; you need this for the bottom of the rocket. The small nozzle increases the thrust of the engine, thus producing more lifting power.
Next, I measured and cut about ½ inch below the nozzle on the second CO2 cartridge. You don’t have to worry about the seal. This nozzle just covers the top of the engine and supports the nosecone.
Step 2:
Now I fitted the engine into the CO2 cartridges to make the rocket’s body. You may have to peel off a few layers of paper to get the engine inside, but it should fit pretty snug.
**You may also want to carve out the ejection charge. I didn’t, but this will keep the rocket from exploding. The ejection charge is on top of the engine (the end without a hole). Carve at it with a knife or scissors and stop when you reach the black spacer. Leave the spacer in the engine, and you’re done.
Anyway, the longer CO2 cartridge with no seal goes on the bottom of the rocket engine (the end with the hole), and the shorter cartridge covers the top ½ inch or so of the engine. Try not to leave too big of a gap between the cartridges, and you can tape both haves together if you want.
Step 3: (NOTE: This step can be skipped until the end.)
This is the ignition system for the rocket:
I first cut off about ¾ inch of that coffee stirring straw and super glued it inside the bottom nozzle of the rocket. Don’t get a lot of glue on the engine; keep it on the straw and nozzle.
Then I carefully squeezed the engine igniter through the straw until it stopped. You might have to straighten out the leads on the igniter with the pliers. Just don’t let them cross, because they’ll cause the igniter to malfunction.
I finally rolled up a piece of the recovery wadding and wedged it in the straw between the leads. This holds the igniter in place and keeps the leads from crossing.
(Don’t worry about clogging the nozzle. The igniter, straw, and wadding will burn up really fast.)
Step 4:
Cover the straight part of the rocket’s body in the paperboard or notebook cover, which I used, and tape it on.
This is the hardest part of the build:
Using the leftover paperboard, I first constructed a nosecone and taped it over the top nozzle of the rocket. It should cover down to the straight body of the rocket.
I then cut out 4 wings, all the same size, and taped them on. I measured out one side of the triangle to 1 inch and the other side to 1 ½ inch; the hypotenuse doesn’t matter as long as it’s straight. I taped the 1 ½ inch side to the rocket and the 1 inch side faced the bottom. Keep the wings on the straight body of the rocket, so they don’t get too hot and burn.
Make sure the nosecone and wings are perfectly even and lined up, because crooked parts cause the rocket to fly out of control and crash. I found out the hard way.
Also if you want, you could cover the entire rocket with tape, like I did, to give it a little more strength.
Step 5:
Check your rocket over to make sure there aren’t any problems, and launch it.
Rubbish Rocket.wmv
Step 6: Ignition Idea
If you are totally clueless on how to launch your rocket, here’s how I did it:
I cut a pop can in half and kept the bottom. I rolled the sharp edges down, and cut a ¼ inch wide rectangular chunk out of the side. I set the rocket on top of the can, which was placed on the ground like a small bowl.
I then tied two 15 foot long wires to the leads on the igniter (positive and negative don’t matter).
Finally, I stood at the other end of the wires and touched them to both terminals of a large battery (I used a small 12 volt~300 amp lead-acid battery).
If the rocket doesn’t ignite, wait about 30 seconds before going over there, and check your igniter.
If the rocket does ignite, it should, and it will, fly really high and explode due to the ejection charge. My rocket burned a hole through the can, and the ejection charge blew apart the top and outside of it.
Any questions…… reread the instructions, and don't be afraid to experiment a little. ;)
Step 7: The Left-Overs
This is what's left of my rocket and base after I launched. As you can see, and if you were paying close attention to the video, the ejection charge pretty much turned it into a bomb....well.... kinda.
The bottom half (in the picture) is the only part I could find. The ejection charge launched it about 30 ft. away and hit a tree almost 20 ft. up.
If you listen closely to the video, you can hear the charge go off and then the rocket hit the tree with quite a bit of force. Have fun, and yeah the rocket doesn't cool down very fast, so don't pick it up right away!
Photos
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