How to Make a Exploding Outhouse!





I am a high school engineering teacher who received two 3D printers this school year (2017-18). My students and I were very excited about using them, so I wanted to create or find a fun design project that implemented the 3D printers for my drafting & design technology students. When I was brainstorming ideas, I remembered how my grandpa used to make these little wooden outhouses that exploded when you would drop a coin in the cut out hole on the top of them.

Unfortunately, I could not find the wooden one that my grandpa gave my family when I was a kid, so I began prototyping!

After evaluating and editing my design, I developed one that worked!

As I mentioned, I am an engineering teacher and therefore I preach proper documentation to my students, especially when it comes to dimensioning their blueprints. With this being my first instructable, I hope it is clear and precise!

How the exploding outhouse works

The outhouse is comprised of six 3D printed parts: 2 walls, 1 roof, 1 floor, 1 front door, and 1 back door. You also superglue the mouse trap into the base of the floor. Once assembled, the mousetrap will be 'set' on the inside. When someone drops a coin in from the top, the coin triggers the mousetrap of which goes off a hits two prongs that are opposite of each other on the inside of both walls. Then Kaboom, the outhouse explodes and usually scares its victim.

How the project is implemented in education

I implemented my design by having my students reverse engineering my final product. So they took apart my outhouse, measured each part with calipers and build them on Autodesk Inventor. I embossed the words “Sedville,” “Outhouse,” and a crescent moon on my design, but I encouraged my student to emboss their own designs/words if they wished. "Sedville," is the previous name of my town; decades ago when outhouses were more common.


3D Printer & filament (I used Lulzbot’s TAZ 6 & Polylite PLA filament)

CAD software (I used Autodesk Inventor)

Victor Mouse Trap

Gorilla Super Glue

1 Coin

*Note* this project is totally customizable. Feel free to make it out of wood if you wish like my grandpa once did. Feel free to experiment with other filaments too! I look forward to seeing what you guys come up with.

Recommendations for wood

If you decide to make your outhouse out of wood, I recommend that you used 5/8” screws for your prongs. Also, after you have screwed in your prongs, I recommend covering the end of the screw with some type of small tubing as seen here. I recommend the screw tubing because when the mouse trap goes off, it will not catch the threads on the screw, and therefore will produce a better explosion.

Terms/Symbols Used

Emboss – a tool on Autodesk Inventor were you can engrave or extrude words and/or 2D shapes.

"R." - stands for the radius of a circular feature on an object

"Ø" - stands for the diameter of a circular feature on an object

Step 1: Create 3D Parts

As long as you know how to read blueprints and how to measure, you should be good to go! If you do not know how to use a type of CAD software, I highly recommend creating it out of wood; stain it and make it look real nice! All of the dimensions are in inches.

Step 2: Glue in the Mouse Trap

Super glue in the mouse trap to the build-in indention in the base of your floor. If you build it according to my blueprints, the mousetrap should be centered on the floor. I used gorilla super glue. The mousetrap might be a tight fit, but it should work.

Step 3: Assembling

Be careful when you assemble your outhouse so that you do not accidentally activate the mousetrap.

Step A:

Set the mousetrap.

Step B:

Insert the walls where the prongs are directly above the mouse trap's hammer. The hammer is the piece of metal that flips and hits the mouse when triggered.

Step C:

Carefully insert the back door and front door when pinching the walls, as seen in the photos. I recommend pinching the walls so that the doors do not fall in on you and accidentally activate your mousetrap.

Step: D:

Carefully rest the roof on top of the outhouse, so that the bars are resting on the outside of your walls and doors, as seen in the photos.

Step 4: Video

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    11 Discussions


    1 year ago

    This is a great project for a class. Easy in conception but made up of more than just a couple of parts. I love the video at the end! Parts crashing. The sound is fantastic.

    Antzy Carmasaic

    1 year ago

    Imagine this implemented in a real outhouse. As soon as someone sat down and dropped "it" in the pot, bam, all the walls fall away leaving you sitting naked on the hotseat visible to anyone present around. Could be an April Fool's prank.


    1 year ago

    Also known as an exploding tax shelter.


    Question 1 year ago on Step 4

    O.K., I don't want to make this as an exploding anything, but I am fascinated by your design! Is it possible to give the dimensions in inches? I would really like to make - sans the mousetrap - a bird house, out of wood, using this design.. But, I just may make an exploding outhouse in the near future:) Thanks

    1 answer

    Answer 1 year ago

    Yes the dimensions on my blueprints are in inches. My apologizes for not stating that in the intro.


    1 year ago

    So cool. I'm still laughing... mean thoughts I suppose. I gotta get one of these.

    1 reply

    1 year ago

    i have seen some that have the door on a hinge. when you open the door the mouse trap is released, thus sending the parts flying all over the store.
    you could modify this by removing the "prongs". you would still get a surprise without parts flying all over.


    Tip 1 year ago on Introduction

    Just a “loving” comment. Your requirement of providing complete, through documentation will provide your students with a skill set that will help to insure their success in their future endeavors. You might look back on your documentation above. Specifically your grammar structure. Poor structure takes away from a readers concept of the quality of your work. Just saying.....


    1 year ago

    That's a fun toy :) I hope you find the one your grandpa made too :)