Handheld Rocket Launcher!!

Intro: Handheld Rocket Launcher!!

Back when I was in High School (early 90s) boredom inspired me to create a handheld rocket launcher out of miscellaneous parts I found in my dad's garage. It worked spectacularly.... ONCE. After that I never got it operational again, and it eventually found its way back into the pile of parts. Recently I have been feeling exceedingly nostalgic and for the past few years I've felt the urge to create a new & improved version. So I now proudly present to you, The Handheld Rocket Launcher Mk II.

PLEASE NOTE: The legality of this item falls into a bit of a grey zone (similar to potato cannons) The state of Arizona is especially interesting since Model Rockets are legal, but any type of firework or sparkler is not. DO NOT aim this at ANY living thing!! USE COMMON SENSE and SAFETY if you choose to build/use one of these. It is for educational and entertainment only, as it has no practical value at all. To put it bluntly, don't be an idiot with this thing. I'm not responsible for any accidents you may incur.

STEP 1: Concept

The Launcher is powered by a 9 volt battery. The power has an illuminated safety switch and will not fire unless the switch is "armed." Pull the trigger and a current is passed through the copper barrel as well as a steel washer at the base of the barrel. If a properly constructed "Missile" is loaded at this time, it will complete the circuit, lighting the igniter and the Missile will be launched from the barrel.

STEP 2: Materials

1" dia x 24" copper pipe

1" threaded copper adapter
1" threaded pvc cap

piece of leather (optional)

wood, 2 1/2" x 24" x 1/4"

Wood screws #4 x 5/8"

#12 x 2" Machine bolt w/ nut (not shown)

18 Gauge speaker wire (I also used other smaller wires as well)

Insulated ring terminal (2 different sizes)

2) fender washers 1/8"X3/4"

Momentary contact Push button

Illuminated toggle switch

9volt clip

1" insulated clamps

Steel Rivet 1/8" dia x 1/2" grip

STEP 3: Tools

Drill

Jigsaw

Miscellaneous drill bits (including 1/2" & 1") (not shown)

Screwdriver

Dremel (Required for virtually EVERY project!)

Needle nose pliers

Wire Strippers

Torch

Rivet Tool (what's the proper name for this??)

Soldering Iron (optional but recommended)

Ohmmeter (optional but recommended)

Hot glue gun (optional but recommended)

STEP 4: Copper Work

Solder the copper fitting to the pipe.

It's recommend to coat the end of the pipe and the inside of the fitting with Flux prior to soldering. It helps the solder flow into the joint.

Using the torch heat the fitting, not the pipe itself.

Once hot enough the solder will melt and be sucked into the joint.

Wipe down with a rag and let cool.

STEP 5: Wood Cutting

Using the supplied PDF layout, mark out the pieces onto the wood as shown.

Start by cutting the strip with B, C, & D off. I used a jigsaw, but a table saw would have been much better for this step.

Cut out pieces A & B next.

To create a perfect curved end to B & C, clamp them to a working surface, and then drill out the circle using a 1" bit.

Do not drill the holes for the buttons yet!

STEP 6: Handle Construction

Mark out the locations of the button holes and ends on the wood pieces. You will need these lines to locate the holes for the screws.

Be sure to stagger the holes in such a way that they don't enter any of the button holes, and they won't hit each other. I went a bit overboard with the holes. You'll see in photos of the final product I didn't need this many. Use your own discretion on this step.

Since the heads of the screws have a taper on them, we'll need to countersink the holes a bit. If we don't there is a good chance the screws will split the wood. I used a small boring bit on the dremel to create the countersinks.  

Assemble the handle. Be sure to use pilot holes for the screws so that the wood does not split! 

Drill the button holes using a 1/2" bit, keeping them as centered as possible. 

I decided on a whim to stain the handle. Definitely not required but adds to the "cool factor" ( an important quality in all of my instructables)

STEP 7: Handle Attachment

For me, this was the most difficult part of the build. Take your time on this step.

Take the two 1" clamps, and if yours are insulated, remove the insulation.   Bend them so both legs are an equal lengths. 

Next, position them over the barrel and onto the handle in such a way that the bracket will hold the handle flush. Drill a 7/32" hole through the handle. It will have to be located so as to miss both switches. On my prototype it was a little bit loose, and I had to resort to using the hot glue gun to keep the handle from slipping around on the barrel.

STEP 8: Ignition System

Open up the handle and install the electronics per the attached schematic.

Make sure the threads on your buttons are long enough to penetrate the wood. I almost had to countersink my trigger!

When you have it put together, pull the speaker wire almost all of the way apart. Cut the positive lead to just a few inches long and attach a ring terminal large enough to go over the #12 bolt. The negative lead should be about 16" long

Once wired up, it is recommended you test the system using your ohmmeter. Set it to 10V DC test and connect it to the end terminals. You need to verify there is ONLY a charge when both the safety switch is on AND the trigger is pushed. This is a very important step. You do NOT want this thing firing unexpectedly.   The safety switch should illuminate when it's "armed".

To eliminate the possibility of a short, I filled the button terminals with hot glue. Next, scuff up the top of the battery clip and using wood glue, attach it to piece "D". I used cellophane tape to secure it in place while the glue dried. 

STEP 9: Barrel Porting

I chose to "port" the barrel for a couple of reasons. First it (hypothetically) will reduce turbulence for the missile by allowing the gases to escape from the sides of the barrel instead of competing for room at the mouth of the barrel. Other than that, it looks rather cool, and I'm anticipating short flames/smoke shooting from them. ("cool factor")

Begin by printing the attached template and taping it to the end of the barrel. Start each port with an 1/8" hole, and then enlarge to a 3/16" bit. Do not apply too much pressure with the drill or you could deform the barrel.

After the holes are drilled take your dremel or a file, and spend the time to make the inside of the barrel smooth again. If it's not smooth enough the fins of the missile might get caught and it wouldn't be pretty.

STEP 10: Handle Attachment

With the handle reassembled cut a small notch in the arch above the safety switch with your dremel. 

Lay the wires in this notch and then attach the handle to the barrel with your 1" clamps and bolt. Slip the positive lead ring terminal over the bolt. Wrap the negative lead around the barrel a few times and cut to the desired length. Attach the smaller ring terminal to the negative lead.

STEP 11: End Cap Construction & Testing

Drill a 1/8" hole in the cap. Widen it slightly.

Starting from the outside, the rivet should pass through the ring terminal, a washer, a piece of cardstock (more on that in a second), through the cap, and then secure the second washer inside the cap.

The cardstock was a good idea that didn't work well at all. I wanted the ring terminal to be able to spin on the rivet. I had planned on ripping the cardstock out but the rivet gripped too hard and I never got it out. Perhaps if I had put the cardstock on the other side of the washer it would have worked better.

After this step is complete get out your ohmmeter again. Set it to 10V DC and touch the positive probe to the barrel and the negative to the inside washer on the PVC cap. Verify that you are getting 9 volts when the trigger is pulled.

STEP 12: Missile Construction

Materials needed:

Pack of rocket engines (with igniters and plugs)

Printed templates from step 6

Thin conductive tying wire.

Any standard size rocket engine will work. I had some B4-4s laying around that I used. The ideal rocket would be a C engine used for glider rockets. These have no ejection charge, so they have a better power to weight ratio.

Cut out the fins and nosecone templates. Bend the fins in a series of peaks and valleys as shown. Wrap and glue around the TOP of the rocket engine. These cannot go at the bottom of the rocket or it will not sit properly inside the PVC cap. Next, cut out and glue the nosecones on as shown.

Install the igniter as you normally would using the plastic plug. Remove the tape holding the leads together. Bend one lead up the side of the rocket. Twist the other lead into a coil-spring. These leads MUST NOT TOUCH or it will not fire. Cut a piece of tying wire and loop it against the straight lead, securing in place with a small piece of tape. This tying wire must bend outward as shown to ensure it makes contact with the copper barrel.

STEP 13: Launch Video and Aftermath

It works, but the rockets weren't nearly as stable as I had hoped.  Possible solutions? Perhaps using different strength engines would help. Or creating a longer missile by taping a used engine to the front of a fresh engine?   Weighting the nosecone? 

The escaping gases actually stung my hand a little bit. (but didn't singe any hairs) 

The rocket has to be cleaned out at least a little between shots. If there is too much residue in the barrel the ignition wires can't pick up the current.

Have fun and be sure to let me know any improvement ideas you have!

(If you enjoyed this instructable please rate it, and be sure to check out my other projects!)

Comments

[Nikolai Nielsen]

the sound of the slomo sounds like a barking dog experiment.

[fancypants23]

nice. i tried making black powder once and ut wasnt fast burning but would probably be good for something like this. might try ut out lol

[littlewit]

Fins would be ideal to stabilize something like this. Obviously, since it is being launched from a tube, conventional fins are not possible, however some real rocket launchers like the RPG-7 use spring loaded stabilization fins (someone actually talked about this on instructables). It would take some time and engineering but it would be both effective and awesome if you pulled it off.
There is also the idea of gyroscopic stabilization. An experimental US firearm called the gyro-jet tested in the early '60s was actually a handgun that fired miniature rockets instead of bullets. The exhaust from the rockets was precisely angled to make the rocket spin like a football (American). This method would be much harder as it requires precise machinery and mathematical calculations, but kudos to any of you out there who can make it yourselves!

[AR10NZ]

Gyro Jet actually produced pistols, rifles, & flare launchers. I have a launcher, and some flares. The launcher is black anodized aluminium, & stainless steel. The flare is pushed into the launcher, the spring loaded knurled knob, is pulled back & released, causing the firing pin to strike what appears to be a small pistol primer, igniting the propellant. The copper base has 2 holes that are canted, the exeting gasses cause the flare to rotate, in flight. It burns bright red, accelerating out to about 400 meters very quickly.
The pistol & rifle were novelties, but at US$2.00 for each, were not popular.

[tinker234]

something like a pez snap back bascally a fin on a spring the push of the bareel makes them stay in and pop out when there at the end of the barrel

[tinker234]

something like a pez snap back bascally a fin on a spring the push of the bareel makes them stay in and pop out when there at the end of the barrel

[bartworker]

Good job mate, I like this I'ble very much!!!
I'm sure that making the missiles just a bit longer with some weight at the top - 'arrow-styled' - will make them a lot more stable.
Mosquito's will think twice next time before passing your window... ;-)

[tinker234]

could i add kroylon heat guard then a wood case covered in truck linear

[tinker234]

this rmeinds me of the gyro jet i think i f you use a aftermarket handle and add riffling to the barel it will be more acutarte or add spring loaded fins that pop out when i reaches the end

[Dr.Alski]

Here's a tip I found out years ago that adds to stability when making simple rockets using Estes type engines.The reason a simple "bottle rocket" cruises as straight as it does is the secret is in the stick. Rule of thumb is the stick is 7.5 x the length of the body or engine. For example say your engine is 2.00" long. Get a length of 1/8" diameter dowel rod from the hardware store. Cut off a 15" length and wrap it to the engine using masking tape ( one end flush with the nose end of the engine and the remaining length at the exhaust end ) just like a common bottle rocket. We used a fuse we pulled out of a firecracker and stuffed it in the ignition end. Position it same as you would a bottle rocket and see the improvement as far as stability. TIP: not too much tape or you're adding weight and it won't fly as straight.

[Dia1Up]

You have your fins at the front.... simple leverage stats that the propulsion has leverage over the fins, instead of the fins having leverage over the propulsion. I'd put bigger fins at the back, and maybe not out of paper ;) Those speeds are a bit too fast for paper.

Or like Madrais said, angle the fins as such to give it spin

[lmperkins]

Nice job and a nicely made instructable.

[illfixthatone]

"Rivet Tool (what's the proper name for this??)"
The term your looking for is "Pop rivet gun" :-)

[nof-z]

EPIC!!!, but a little safety info, if the rocket does not fir immediately, do NOT look down the barrel immediately, wait at least 30 seconds, then get it out, this is called a squib load. watch video to understand. over all, awesome. and i agree with buffalonickel, but instead of flash powder, use those things you throw on the ground that pop to make it go bang, and use the big ones.

[BuffaloNickel]

Weigh the front of the missile down. By "weigh" I mean add a small amount of flash powder. By "small" I mean as much as you can fit.

[geckomage]

haha, i love the way you think my friend. for any that need to know flash powder can be made by finding out how to do it on google, a particularly good recipe in a book called "Steal this Book!" written by a libertarian no less ;) though i will not tell you how on here because i dont want to be responsible for people blowing themselves up and i do not wish to get in trouble. If you attempt this make sure you create it in small batches, store it in isolated places away from heat and flame, as well as away from you. be safe, use common sense! :)

[ncc 1701]

cool idea but you know someone is going to be stupid with it

[batonas]

your rocker are completely unstable you could try to make springy wing stabilizer (wing that deploy then the rocket is out of the barrel) with wing stabilizer the center of gravity should be more in front so put some weight in front or better a small bomb but before puting a bomb make sure its stable.

[scubaru]

Well when rockets are usually shot off there isn't more than a platform that it blasts on. Since this is less than half the weight why not just remove the entire end cap. Making like a bazooka tube. run 2 wires across the open end like cross hairs. This way you can keep the wires clean.

I want to try this but make a little "pop" at the end since it already blasts forward for what is suppose to be the parachute eject.

[Adithyaa Designs]

Here is a bit of good advice

1. i had this idea with PVC when in the 5th but i thought of using a fireworks rocket and PVC.
2. you could make this system breech-loading by shrinking the size of the rocket and putting it in a tube that fits into the launch tube. this would also prevent loose contacts and prevent the rocket from falling out.
3. regarding the build up that needs to be cleaned, you could make a ramrod style device for pushing the rocket in and later cleaning the tube.
4. you could put small flaps on the side of the rocket which are pressed flat to the body. when the rocket is fired the flaps will open with the wind and spin stabilize the rocket.
5. you could take a funnel, chop of the spout and fit to the front of the luancher, then it would prevent the singing.