I Made A T-Shirt Cannon For $10… And So Can You!

28 Jun

DISCLAIMER:  Should you choose to build anything based on our design, do so at your own risk and don’t sue me if you injure yourself doing something stupid

I have a confession to make: I’ve always wanted a t-shirt cannon.

Why? Because (a) I’m a kid at heart,  (b) I like making things, and (c) t-shirt cannons are the coolest. If you found yourself nodding to any or all of those reasons, read on!

My friend Aaron (of “Friday Finds” fame) and I were able to find a number of plans and schematics online for air cannons, but a number of issues with this style of cannon became apparent:

  • Can’t fire it too many times- We found a few home-built models that could hold as many as 6 shots in a pressurized tank without be refilled or models that needed to be “recharged” with a bicycle pump after each firing
  • Complicated builds- Many of the builds appeared doable, but definitely complicated and potentially dangerous (The manufacturers of PVC pipe and fittings as well as OHSA warn against using PVC piping to convey compressed air as it can explode, causing serious injury or death in some cases.)
  • Moderately expensive to build- Around $100 (which doesn’t sound like a lot, unless you work in Christian radio).

In other words, an air cannon was out of the question. Fortunately, I got an idea: a guided slingshot cannon.

IMG_20130627_170549

The cannon alongside a t-shirt projectile
(ruler included to show scale)

Essentially it works the same as that slingshot you owned as a kid, but offers more control. The slingshot style t-shirt launcher that we designed was made of four components:

  • 2 feet of surgical tubing (1/2” Outer Diameter, 1/4” Inner Diameter, 1/8Wall)
  • 4 feet of PVC pipe (4″ diameter)
  • 6 feet of rope
  • An empty plastic spool (old wire spool from Radio Shack that we had laying around)

The build is easy… almost too easy assuming that you have the above materials and an electric drill with a set of large bits (the biggest we had was a 5/16″ but a 7/16″ would have worked better– we ended up boring out the sides a little)

Step 1: Drill two holes on either side of the “plunger” and thread the tubing through so that there is an even length on both sides. Make the holes big enough to get the tube through by cinching it on the sides, but not so big that it slips around.

IMG_20130628_130558

If you can’t find a plastic spool like we used, you could use a plastic kid’s bowl/tupperware, a tennis ball, even a piece of wood cut to fit. Be creative! Be careful the plunger isn’t too wide or it might jam while firing.

Step 2: Thread rope through the core of the plunger and tie a strong (and sufficiently wide) stopper knot. If it is not big enough, it will become apparent after a couple of firings (when the knot slips through and you accidently fire something into a person/the woods because you haven’t aimed it yet).

IMG_20130627_170837

We used an oysterman’s knot.
(Click the picture for instructions)

Step 3: Drill two holes in the PVC about an inch and a half from the end of the barrel. Thread the tubing through and tie off on both sides. The plunger should rest a little more than half a foot beneath the barrel of the cannon.

IMG_20130627_170906

If this seems short to you, don’t worry! The tubing produces optimal force when it is stretched to 5x it’s normal length (which puts the bottom of the plunger close to the bottom of the PVC pipe when fully pulled back).

Step 4: Create another knot with which you can step on to pull back and hold the weight of the firing plunger.

IMG_20130627_171019

We used a bowline knot so that if we wanted, we could slip our shoe through to hold it
(Click the image for instructions)

That’s it! The cannon is ready!

In order to fire,

  1. Load the rolled t-shirt/tennis ball/etc.
  2. Firmly grasp the sides of the cannon
  3. Step firmly on the bottom loop (standing on concrete rather than grass will increase your foot grip)
  4. Slowly raise the cannon, pulling back the plunger till it is almost at the bottom of the pipe
  5. Release quickly! (step off the loop)
IMG_20130627_170941

(Image captured before I took out a ceiling tile in the basement)

The lower you aim the barrel, the more distance, but it will be a tighter arc. Aim up and it will fire higher, but it won’t go nearly as far. (I don’t know why I’m bothering to tell you all this… hasn’t everyone played Angry Birds at some point?).

Our particular model will sling a t-shirt about 60 feet (see the video at the top of the post), but you could feasibly mod our design by extending the barrel and tubing length or by using four tubing arms on the plunger instead of two. You also might consider using a wider PVC pipe if you want to fire wider projectiles.

Happy t-shirt flinging, and remember: Safety first!

-Dave Wonders

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Yes, “David Wonders” is his real name. Dave is  a husband, a father, and the midday host at 104.3 The Pulse (thepulse.mn). Somehow he finds time to read absurd numbers of books.  Connect with Dave on TwitterFacebookLinkedIn, and Klout.

9 Responses to “I Made A T-Shirt Cannon For $10… And So Can You!”

  1. Dave (@AxsDeny) June 28, 2013 at 18:58 #

    I love the design. My only concern with this design is the release process. If the barrel happens to slip out of your hand it will be sent screaming towards your poor, defenseless toes. Perhaps it would help to add a wrist loop at the top so that if it does slip it will be kept from severing your toes?

    • More Than A Beard June 28, 2013 at 19:03 #

      Good insight, Dave! After 3 dozen firings, we haven’t had this happen, but it is definitely within the realm of possibilities. One idea we had was to apply some kind of grip tape, but a wrist loop would be a good idea too… I wouldn’t recommend operating the cannon without sandels.

      • Dave (@AxsDeny) June 28, 2013 at 19:39 #

        Heh. Yeah. That’s one of the situations where it only has to go wrong once. Someone gets a little overzealous and pulls the tubing to its extreme and it slips. WHAM. Broken foot.

  2. Mike C October 18, 2014 at 09:08 #

    You could drill a hole through both side of the pipe at the bottom for the insertion of a firing pin. It would sit against the back base of the spool when set in launch position. In that way you could place the butt end of the pipe on the ground for recoil support.

  3. Noah January 15, 2015 at 09:32 #

    Do you know what kind of surgical tubing you used? And where you got it? Thanks!

    • Dave Wonders January 27, 2015 at 12:57 #

      2 feet of surgical tubing (1/2” Outer Diameter, 1/4” Inner Diameter, 1/8” Wall). We got it at a medical supply store… I recommend calling ahead because not every store carries tubing.

  4. kalah January 27, 2015 at 11:02 #

    were your parents mad about their ceiling tile?

  5. highjumpgirl March 10, 2015 at 18:56 #

    Dave, thank you so much for this idea! It is absolutely brilliant! We have an ice cream boat business on the coast of NC, and we utilize music, a bubble machine and other goodies. We’d thought about a t-shirt cannon, but they are $1000 range. Today I discovered that we have way too many t-shirts and need to give some away. How lame it would be to throw them at a crowd, I thought, when we pull up to an island and are bombarded by ice cream customers. “We really do need a t-shirt cannon!” So I thought, there has got to be a way to make one… and I saw all these complicated designs… and am so thrilled I found yours. Ingenious, and I can’t wait to use it…. shooting t-shirts at beachgoers. I’ll try to video & photograph it. THANKS! http://www.TheIceCreamFloatBoat.com

  6. Eric T. July 16, 2017 at 20:47 #

    Thanks for the cool design! I’m just wondering how critical the wall thickness is? The stuff at the hardware store seems to be around 1/16″ thick rather than the recommended 1/8″. Do you think 1/16″ wall thickness would be okay? It’s clearly not as strong as the 1/8″ walled latex tubing.

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