Instructables

World's Most Powerful Marshmallow Gun -- How To Make Your Own

video World's Most Powerful Marshmallow Gun -- How To Make Your Own
This is how I built my single-action barrel sealing piston valve air gun. This gun shoots as fast as you can pull the trigger and really exceeds the power and velocity that one would reasonably want to shoot marshmallows at. Please don't build one with the idea of using it for marshmallow war games. I know from personal experience that, getting shot with a nice, fluffy marshmallow out of this gun will raise a serious welt, even through denim. Who knew that something so soft and fluffy could hurt so bad?

I believe the design is unique and achieves a faster rapid-fire rate than any other piston valve gun design, because it eliminates the valve that other designs require to isolate the air compressor before firing. This gun is pressurized through the pressure chamber, not from behind the piston.

This instructable is extreme, because it is the world's most powerful marshmallow gun - blowing away any other marshmallow gun to an extreme.
gemoney5 months ago
can you make it fire bbs
Glaspack2 years ago
I can not seem to get the piston to operate correctly. Could you post some more instructions on the piston setup, or could I just buy one from you.
wwiismith2 years ago
Mr. Shoe maker if you would please give me some more information of your pump action design on this instructable thank you for your time. This is an amazing weapon
najc12252 years ago
a little help please i tried it but i wasn't able to get it to fire.
shoemaker (author)  najc12252 years ago
It is hard to know what the problem might be without more info, but if you have built it correctly to the point where the gun is presurizing, but just not firing, then the problem is likely one of 2 things:

1. Your trigger doesn't release air fast enough. Try removing all hose and everything right up to the back end of the T joint that has the pison in it. Then try blocking the hole with your thumb and releasing it. If it fires like that, then you just need a trigger valve that will release air more efficiently.

2. Too much air is leaking around the piston to the back where the trigger hose is. This means that as fast as you dump pressure with the trigger, the pressure behind the piston is being replaced faster by the said air leaking around the piston. The solution to this is to get a higher tolerance fit between the piston and the cylinder. The piston should slide smoothly, but otherwise completely fill the diameter of the cylinder. I added one thickness of scotch tape to my piston and that made all the difference.
Jewson2 years ago
Have you thought about shooting paintballs?
[corosive]2 years ago
could this feasibly be built using a bike pump instead of an air compressor? i know you wouldn't get the quick-firing because of the lack of continuous pressure.
shoemaker (author)  [corosive]2 years ago
If you want to use a bike pump it would be easier to make the pneumatic potato cannon from my other instructible. That one uses a sprinkler valve. It will save you time in building and will likely work better with non-constant pressure.
CaseBoy2 years ago
this is amazing. this so on the next "things to build" list