Introduction: Double-Barrel Shotfun

Picture of Double-Barrel Shotfun
It was just a spelling mistake in a humorous sub-thread, but it eventually became...

The Double-Barrel Shotfun - dealing out enjoyment at the pull of a trigger!

It's just what you needed - an overly-complex method of firing off two party-poppers at once.


(You can now accessorise your Shotfun with a dedicated bandolier!)

Step 1: Materials and Tools

Picture of Materials and Tools

You can modify this project to your needs, but this is what I used:
  • 4mm plywood sheet
  • Offcut of 6mm plywood
  • 32mm waste pipe
  • Industrial adhesive
  • Masking tape
  • 6mm dowel
  • Scrap corrugated card
The tool list is flexible - I used a laser cutter, but only because I could.  Similar results could be achieved with skilled use of traditional power and hand tools.
  • Lasercutter
  • Scrollsaw
  • Teaspoon
  • Files
  • Sander
  • Rubber mallet

Step 2: Prototyping

Picture of Prototyping
I first needed to prove that my idea worked.

This quick lash-up proved that a steady pull via a lever would work to fire a party popper.

Step 3: Lock, Stock...

Picture of Lock, Stock...


Once the concept was proven, I needed to stream-line it. I drew the laser cutting files in LaserCAM 2D, purely because it's the software my school bought with the laser cutter.  You can reproduce your own version in whatever software you prefer.

I designed most of it to be out of 4mm ply, but I decided that the section that would brace the poppers (the part that looks a liitle bit like a heart, and a little like a Batman logo) needed to be stronger, so I cut that out of 6mm plywood.

I took a screenshot of the design that you can use - the odd layout is to fit the piece of plywood I had close to hand.

The MCM file itself is in the zip folder with this step.  It's not huge, it just isn't recognised by the uploader if you leave it as an MCM.

Step 4: Testing & Cutting

Picture of Testing & Cutting

To check the parts fit together, and fit my hand, I ran off a set of pieces in corrugated cardboard.

The parts all fit perfectly, but I discovered a bug in the software; the curves of the bracing piece were only rastered (etched), not cut by the laser cutter.  I ended up using the rastered cardboard test-piece as a template for the bracing piece, which I cut out roughly with my scrollsaw, then filed and sanded it to shape.

Step 5: Construction

Picture of Construction

See the photos for laying the parts out.

I used short pieces of 6mm dowel to brace the parts.  The fit in the laser-cut holes was snug, so I used a small rubber mallet to get them in place, protecting the gun with a scrap of timber. Wood-glue between the layers ensures a permanent fix.

Beware!

Watch which way round you fit the lever - the slot needs to face backwards - and be careful not to glue it in place.  It's not obvious from the images, but the hole I cut in the lever is half a millimetre wider than the other holes, so that the lever will move freely, not stiffly.

I sanded the dowels flush with the plywood, and cleaned off the cutting soot with a few strokes of the same sandpaper.

Once the rest of the woodwork was glued, I glued and friction-fitted the bracing piece in place.

Step 6: Making Barrels

Picture of Making Barrels

I cut two pieces of waste-pipe for the barrels, each just over 40cm long.

The waste pipe I used was sold as "32mm diameter", which turned out to be the internal diameter.  This was the closest fit I could get to the 26mm outer diameter of the party poppers.

I could have bought 28mm copper tube, but it cost far, far more than the plastic waste pipe, and I'm not convinced that party poppers come in a standard diameter, so there's wiggle-room to fit larger poppers.

To be able to load the gun, I needed a notch out of the barrels.  I measured it by eye, then cut it with the scroll-saw.  The curved slot gives enough space to push the popper into the barrel, and then drop the stalk of the popper into the notch of the bracing piece.

See the photos for the size of the notch compared to the poppers.

Step 7: Fit Barrels.

Picture of Fit Barrels.

With a spare set of hands (thank you, Kitewife!), I fitted the barrels in place with masking tape, and then filled in the gap between the plywood and the barrel with Sugru.

To do the full length of the barrel took two sachets of black Sugru.  I rolled the Sugru into "worms", then used the end of a teaspoon to push the worms into the gap under the barrels, and to smooth off the surface. See the Sugru packs and website for correct handling procedures.

Disaster!

The Sugru failed! It may have been a lack of contact area, or the age of the packs (rather close to their expiry date), but it didn't survive some basic handling, do I cleaned off the Sugru, and tried again with an interesting mastic-style industrial adhesive called Sticks like sh*t (seriously,  check the photos! ).

Step 8: Finishing

Picture of Finishing

Here, I reached a dilemma...

My original intention was to paint the barrels matt-black, and use a dark varnish on the stock (to make the shotfun look more like a shotgun), but now, as I've been playing with it, the plastic-and-ply colour scheme has grown on me.  I like it, and, for now, I'm going to leave it.

Step 9: Modified Ammunition

Picture of Modified Ammunition
Paper streamers are fun, but it's more fun to cover folk in flour!

Party poppers are very simple to modify, as long as you take a little care:
  1. Use a thin blade or long fingernail to prise out the cardboard disc, doing as little damage as possible.
  2. I remove the existing streamers, but you can leave them in if you want.
  3. Do not remove the second disc - I tried it, to fit in more flour, but the popper's explosive needs space to expand. If you pack things around the popping bit, nothing gets fired out.
  4. About half a teaspoon of flour fits in nicely. Don't pack it tightly, or it won't come out.
  5. Slide the original card disc back into place, between the plastic corrugations - sliding a thumbnail around the edge works well.
If you're not taking photos as you go, each popper takes less than a minute to modify.  The results are satisfying...

Step 10: Loading and Using

Picture of Loading and Using
Before using, you need to tie knots in the strings of your party poppers.

To load, push the popper in through the notch, and lay the string through the slot in the lever.  You can load both barrels, and put both strings in the slot at the same time.

Pull the lever, and... !



I have, of course, entered this in the Epilog laser contest; if you would be so kind as to vote, though I doubt I will get to use a laser cutter very much, since both our boys want careers in design and engineering...
 

Comments

Snibril (author)2014-11-30

I used your idea as a base, cut out the shapes from plywood using a jigsaw and it works. I can report though that knotting the string together and looping them over the trigger only fires one shot, the second one does nothing once the string's out. Works for firing the poppers and actually aims the streamers. :)

Kiteman (author)Snibril2014-11-30

Maybe, if you knot closer to the popper?

It would be cool if you could post a photo of your version, or even a video?

Snibril (author)Kiteman2014-11-30

Can't get the knot any closer, so cut a slot in the top of the trigger as with your design, works fine. I'm tempted to cut an actual trigger design into it, just for the look of it. :)

The angle's a bit odd on the photos as I had to fit it all in frame at arms length.

coolbeansbaby68 (author)2013-05-03

What do they use for a charge?

Kiteman (author)coolbeansbaby682013-05-03

The party poppers? It's a small cylinder on the end of the string - when you pull the string out, friction between what's on the string and the lining of the cylinder trigger the explosion. It's very like a match, but faster.

coolbeansbaby68 (author)Kiteman2013-05-03

so is it a form of gun powder?? Hm,mmmm how could ya get a bigger bang out of it ?? Ya got me thinking kiteman lol

Kiteman (author)coolbeansbaby682013-05-03

Packing the stem with gunpowder, instead of flower?

Be careful of the back-blast.

jompon2547 (author)Kiteman2017-11-27

so i will put the flower out ,put gunpowder in about 1/3 of the container

and after that i will put a lot of small piece of projectile like wood or small metal

and that's what you call shot fun

Kiteman (author)jompon25472017-11-30

In all honesty, that would be what you call a couple of lost fingers, maybe an eye.

jompon2547 (author)Kiteman2017-11-30

can i make it abit dangerous plz?

Kiteman (author)jompon25472017-12-02

Haha, it's up to you, they're your fingers!

Stan1y (author)Kiteman2014-12-21

even a small quantity results in total disintegration. was very glad I'd extended the pull stringt and was 20m away

Kiteman (author)Stan1y2014-12-22

Gosh - do you have images of the result?

Stan1y (author)Kiteman2014-12-22

was many years ago before digital cameras were so wide spread so I'm afraid not

coolbeansbaby68 (author)Kiteman2013-05-03

Hmmm. How about a. Shotgun primer or a rifle shell primer?

Kiteman (author)coolbeansbaby682013-05-03

They're your fingers...

Goodhart (author)Kiteman2013-05-03

or eyes.....

Stan1y (author)2014-04-14

having experimented with alternative loads for party poppers don't use blow pipe snaps they go off inside the party popper

Kiteman (author)Stan1y2014-04-14

That might make a good bang inside the barrels, though...

Xixfas (author)2013-07-01

I live your adhesive!! Sticks like sh*t!! Lol

Kiteman (author)Xixfas2013-07-01

It does exactly what it says on the tin.

Xixfas (author)Kiteman2013-08-15

hehe

NightHawkInLight (author)2013-08-08

Very cool, I like it!

ynze (author)2013-07-30

Congrats with a very honorable Epilog Prize :-)

Kiteman (author)ynze2013-07-31

Thank you!

Colleen4614 (author)2013-07-12

This is cool

Kiteman (author)Colleen46142013-07-12

Thanks.

Colleen4614 (author)2013-07-11

Now this is what i'm talkin about!!!

Kiteman (author)Colleen46142013-07-11

Thank you, I think.

Honus (author)2013-07-11

I have to make this for my boys!

Kiteman (author)Honus2013-07-11

Cool - post pictures when you do.

HollyMann (author)2013-06-04

Awesome!!!

Kiteman (author)HollyMann2013-06-04

Thank you!

chrstphrdoornbs (author)2013-06-01

I love this build. I was thinking if you tied the strings of two poppers together you could just load, put the loop over the hammer, and be able to quickly fire and reload.

Great job, may have to make one myself!

M.C. Langer (author)2013-05-29

Awesome project, Kiteman!!! :-)

Kiteman (author)M.C. Langer2013-05-30

Thank you!

M.C. Langer (author)Kiteman2013-05-30

You're welcome!

TheGeek1984 (author)2013-05-29

Lol, my cousin and I bought a ton of these one time with the intent to turn them all into trip-wire traps that would blow flour or powdered sugar at the person who tripped it. We couldn't devise a way that gave us a repeated success, so we ended up storing them until we could revise our plan. Then we forgot about them. I had a few in my car and a friend asked if she could fire one off when my cousin got back into the front seat, so I said sure. I'm still finding powdered sugar in my car.

Kiteman (author)TheGeek19842013-05-30

LOL!

Alex Dee (author)2013-05-29

Yes i finally finished college and finally have a bunch of free time to put on this website.

Can't wait to start

Kiteman (author)Alex Dee2013-05-29

You finished college??

I feel old...

Alex Dee (author)2013-05-26

This must of been great fun to make and use. :)

Kiteman (author)Alex Dee2013-05-26

Hey, SG! Long time, no type!

Yes, it was!

SlickSqueegie (author)2013-05-06

This is great! I love the idea!

Kiteman (author)SlickSqueegie2013-05-06

Thank you!

ToryDidIT (author)2013-05-06

This Double barrel is a great idea i will use it for my Next Nurf shotfun :-)

Kiteman (author)ToryDidIT2013-05-06

Cool - post a picture when you do.

RedneckEngineer (author)2013-05-06

Another thought on ammo mod, try using colored glitter instead of flour for a more festive popper.

Kiteman (author)RedneckEngineer2013-05-06

Oh, cool!

JonnyBGood (author)2013-04-26

If I get some pvc pipe I know what I'm doing! A vote heading your way for now..

About This Instructable

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Bio: The answer is "lasers", now, what was the question? If you need help, feel free to contact me. Project previews on Tumblr & Twitter: @KitemanX
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