Mini 3D Printed Pistol That Shoots

I have always liked mechanical things, and guns are one of them. So when the Big and Small contest came around, I decided to make a small spring powered gun. I made 3 prototypes for the sides and the bolt, and 4 trigger designs and finally I came up with this design.

It is 45mm long, 30mm high, and 8mm wide, and weighs around 10 grams. The barrel is 5mm wide and it can shoot pretty far for it's size.

Here is a list of all the parts you will need.

1. 3D printed parts
2. Spring (no longer that 16mm and no wider that 5mm)
3. Nut and Bolt (the bolt should be 2mm wide and at least 8mm long)
4. Screw (No longer than 7mm and at least 1.60mm wide)
5. Ammunition

Below are the STL files for the gun and the print settings I used.

Right and left halves.

1. Infill: 12%
2. Support: yes
3. Buildplate Adhesion: skirt

Bolt and trigger

1. Infill: 100%
2. Support: none
3. Overhang angle: 60 deg
4. Buildplate Adhesion: skirt

Print times

1. Right half 36 min
2. Left half 36 min
3. Bolt 6 min
4. Trigger 3 min

After the parts are printed, we can start building the gun by attaching the trigger.

First, get the left half of the gun and remove the support. Then get the metal bolt and stick it through the hole closest to the barrel with the head on the outside of the gun. After you do that, you can stick the trigger onto the bolt with the hook going into the barrel.

Now we will attach the bolt and the spring onto the rest of the gun.

First, get the bolt and put it on the top of the gun with the cylinder in the barrel and the notch in the cylinder facing out of the barrel as shown. Then get the spring and place it in between the bolt and the back of the gun.

Important Note Please Read

In order for the trigger to go up easily, I suggest shaving off some plastic on the end of the hook on the trigger and making sure that there is no plastic hanging down into the notch on the bolt.

After that, we can put the right side on the gun.

First get the right side of the gun and remove the nut. Then get the nut and stick it in the hexagonal hole. Then put the right half on top of the left half and screw the bolt into the nut. Then get the screw and screw it in the hole in the bottom of the handle. And now the gun is assembled!

Now the we have assembled the gun we can get to the fun part: shooting it.

First find something for the ammunition. Screws and BBS work good but not Parmesan cheese (I tried it). Then pull the bold back and push the trigger up. Because of how I made the gun, I couldn't have a spring to push the trigger up because it would hit the spring. Then stick the ammunition in the barrel, aim at what you want to shoot, and pull the trigger down. And there you have it: a mini gun that shoots.