Introduction: Pocket Rocket
Runner Up in the
Space Contest 2016
There’s nothing like rockets, fire and explosions to get your blood pumping. Even something as small as this Pocket Rocket still manages to bring out the kid in me.
The rocket is powered by butane gas that is fed into a launch tube. A remote control then activates a battery operated piezoelectric spark generator which ignites the gas, shooting the rocket upwards.
Initially I was going to use the piezoelectric spark generator from the lighter. After some experimentation, I discovered that extending the wires meant the spark became too weak and wouldn't light the gas. I had a battery operated one however which has a continuous spark and works a treat.
The build is a lot of fun and only needs some basic electronic knowledge to build. You’ll need to do a little soldering as well. I’ve included a few diagrams however to help you understand the wiring, so even someone completely new to electronics should be able to build this.
The thing I love best about this build is the re-fueling system. It makes launching the rocket easy and beats having to add accelerate manually each time you want to launch.
Step 1: Watch the Video
Step 2: Things to Gather
1. Lighter light the one in the image below – eBay
2. Small, wooden box – eBay
3. Piezoelectric spark generator – battery operated – eBay I didn't use this one but it will definitely do the trick
4. Remote module – eBay
5. 2 X AA battery holder – eBay
6. 9v battery holder – eBay
7. 2 X AA batteries
8. 1 X 9v Battery
9. Berocca container – your local shop
10. Cardboard and masking tape – for the rocket
11. Solid core wire. You could also just use normal strand wire as well.
12. On/off toggle switch - eBay
1. Hot glue
3. Soldering iron
4. Angle grinder
Step 3: Adding the Toggle Switch
1. On the side of the wooden box, drill a hole large enough for the toggle switch to be attached.
2. Next secure the switch to the side of the box
3. Lastly, solder the red wire from the 9v battery holder to the middle terminal on the switch, and another red wire to one of the side terminals
Step 4: Adding Power to the Remote Module
1. First, remove the receiving module from the black box. You will notice that there are 2 different wire terminals, one with 2 and one with 3. The one with 2 is where you add the power to the module.
2. Attach the red wire from the switch into the positive terminal.
3. Next, attach the black wire (negative) to the other terminal on the receiver module.
Step 5: Wiring-up the Piezoelectric Spark Generator
1. First thing to do is to pull apart your piezoelectric generator. You need to get the circuit board from the inside. The one I used didn’t have a positive wire soldered onto the circuit board so I had to add one. If you are missing a positive wire (red one), then work out where the positive end of the battery was touching and solder a wire to this section.
2. Next, you will notice that there are 2 wires coming out of the end of the circuit board. This is the end that “zaps”. It’s best to solder on some longer wires so remove the ones that came with the piezoelectric generator and solder on some new ones. It’s best to use sold core wire as this is better to bend and keeps in the shape you want it to.
3. Attach the negative wire from the piezoelectric generator to the negative wire from the battery holder. The positive wires will be attached to the receiver module in the next step
The receiver module acts like a remote switch. When the button is pushed on the remote (transmitter), it activates a relay in the receiver which turns on the power to the piezoelectric generator.
1. You need to attach the positive wire from the piezoelectric generator and the 2 X AA battery holder to the receive module.
2. Once they are in place, it’s time to test the piezoelectric generator and make sure that the remote works ok. First, hold the 2 wires that generate the zap close together. Don’t actually hold the end wire as you will get a zap. It doesn’t hurt but does give you a fright!
3. Make sure that the toggle switch is in the on position and then hit the button on the remote. You should get a spark arcing across the wires. Release the button on the remote and give it another go. If everything is working ok, then you’re ready for the next step.
Step 7: Attaching the Berocca Tube
1. Hot glue the lid of the Berocca container to the top of the wooden box
2. Next, drill 3 small holes into the lid. One in the middle, and 2 on the side as shown in the image
Step 8: Adding the Butane Reservoir
In order to power up your rocket, it’s necessary to add a butane reservoir. You can get these from a BBQ lighter (they also have a manual piezoelectric generator which are fun to play with). The reservoir has a little lever on the top where you can push down and butane will escape through the tubing. You can also increase the amount by moving the other lever left ot right.
1. Pull apart the lighter and remove the butane reservoir.
2. Make a hole in the top of the lid for the reservoir to fit into. I just drilled a couple of holes, filed them down and pushed the reservoir into it. Secure it in place with some hot glue. Probably best to empty the reservoir first just to play it safe!
3. Drill a small hole in the top of the lid, large enough to thread the butane tube through.
4. Next, thread the butane tube into the hole in the Berocca lid. You might want to cut down some of the length of the tube here. Just pull out the little brass end, cut the tube to desired length and replace the end.
5. Lastly, push the zap wires through the other 2 holes and ad some hot glue to the bottom of the lid to hold them in place. Add some more hot glue to the underside as well so there are no leaks.
1. Now you have the zapper section done, give it a test and make sure that the gap is correct. If you don’t get a spark, move the wires a little closer together.
2. To make the launcher, you need to remove the bottom from the Berocca container. I used an angle grinder and just cut it off.
3. Remove any burrs etc with a file and then place the container back onto the lid. The reason why I used the Berocca container is it fits tightly into the lid, however, can be removed to get to the zapper wires and butane end.
Step 10: Making the Rocket
Making the rockets is pretty straight forward and you only need a few things to make one.
1. First wrap a small piece of cardboard around the berocca tube. This will be the body of the rocket. Add some masking tape to hold the shape
2. Add some more masking tape to secure the sides properly.
3. To make the nose cone, just make a cone shape with another piece of cardboard and add some masking tape all around it.
4. Next, you need to cut the nose cone so it fits inside the body of the rocket. |Add some blu-tack to the inside of the cone to give it some weight. This will also help with stability. Push the nose cone inside the body and then add some hot glue around the edges to secure it in place
4. Next, cut 3 equal triangles out of the cardboard. these will be the tail fins. Bend the edges and hot glue onto the body of the rocket.
So that's it! You've made a small, but strong and light weight rocket.
Step 11: How to Fire the Rocket
So now you have your rocket launcher and rockets, it's time to launch.
Give your rocket a try. How does it fly? is it popping off the launch tube and flying high or just kinda limping off? If you find that your rocket isn't getting the height that it should be, then here's a few tips to really make your rocket move:
Make sure that there is a good seal between the rocket and the tube. This is very important. Without a good seal, your rocket won't fly very high. The best way to get a good seal, is to add some masking tape, 20mm from the top. Wrap it around a couple of times and put the rocket back on. The rocket should be tight around the tube. Experiment to get the best seal
Increase the amount of butane is being released inside the tube. Increase the butane by turning the lever on the reservoir to the right.
Only put a couple of seconds of butane in the tube. Don't release too much butane. Remember, you need a good mix of fuel and oxygen to ignite the butane and make the rocket fly. Too much and your fuel won't ignite.
Blow into the tube after firing. If you are finding that your fuel won't ignite after firing, you might have some stale butane inside the tube. Remember, you need oxygen as well as fuel to ignite the butane, so blowing in the tube will clean out the stale air
Make sure that there is a good seal between the rocket and the tube
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Please be positive and constructive.