Picture of Pump-Action Marshmallow Gun
I was bored one day so I decided to make a gun to shoot my brothers with.  I needed a projectile that was soft, readily available and inexpensive.  The answer:  marshmallows!  A marshmallow gun is usually very simple:  a tube that you put a marshmallow in.  You blow in one end and the marshmallow flies out the other.  I wanted to make something more complex.  I got a one-way air valve, some PVC fittings and a ball valve and created...(drum roll)...the pump-action marshmallow gun!

This is my first instructable so feel free to leave comments and tips.
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Step 1: Materials

4 1/2" PVC 90 degree joints
1 1/2" PVC coupling
1 1/2" PVC ball valve
(I think you have discovered by now that all the PVC components are 1/2".)
1 PVC tee
1 PVC one-way valve (Look for it under the name "check valve")
1 PVC end cap
Assorted lengths of PVC pipe (1/2", of course)
Dowel that will fit into the pipe
Rubber stopper

Step 2: Assemble the Stock

Picture of Assemble the Stock
The stock is made of all four angle joints and the coupling.  Fit all the pieces together but don't cement then yet.  We will need to adjust this later.  The picture probably explains better that I could put into words.  After all, a picture is worth a thousand words.
(The stock also doubles as an air tank.)

Step 3: Assemble the Barrel

Picture of Assemble the Barrel
Now we come to the barrel.  For the barrel, take the ball valve and cut a short length of PVC to connect the valve to the coupling of the stock.  Cut another short length of PVC to connect the other side of the valve to the tee.  On the other side of the tee, put a long piece of PVC.  This is the actual barrel.  Make sure you get it to the right length for you.
Again, don't cement the pieces together!  (I made that mistake.)
Note:  I attached a short bit of wood to my ball valve to make it easier to turn.  That is what the long wood thing is in the picture.
sprnklz542 years ago
Could you use nerf darts in this?
Never mind lol. I should read everything before I comment!
siegeking2 years ago
i'l try and build won if i can find the parts!
[corosive]3 years ago
how much did it cost? i love the idea of the integrated pump! another idea would be to use two pumps both running into the stock. this should help reduce the pumping time between shots
have you tried gummy bears, in my experience they fly much better and faster, expect 3-5X distance and still more accuracy than marshmallows
poikilotherm (author)  drycerealman3 years ago
I never thought of that! Great idea! I will try it as soon as I get my hands on some gummy bears.
WYE_Lance3 years ago
This seems like a fun alternative to using a bicycle pump. Can you show us a video of how well it performs?
poikilotherm (author)  WYE_Lance3 years ago
Unfortunately, the gun was destroyed by accident. I made a similar gun later, and it shot NERF bullets for about 150 feet, but marshmallows actually don't do very well. The gun shoots them much faster that their terminal velocity, so they don't have a very stable flight.
here are some pictures of my air gun. it is inefficient, has a uselessly big air tank, is heavy, needs an air compressor to fire, and is single shot between refills but all that can be fixed if i use a pump like yours does. the second picture shows how i set up a breech loading system. there are pvc repair pieces designed to fit over a leaky pipe and if you dont tighten the ends they slide easily over the holecut in the barrel.
Kiteman3 years ago
I think we need to see this in action...