For about a year now I’ve wanted to build one of these mini safes. I went about it in different ways like 3D printing and cardboard, but only recently I’ve gotten inspired to make a metal version. So here it is, my first instructable and instructions for this amazing little safe.

All it takes is a few basic tools and materials and a little dedication and time. If you are like me and don't have any motorized cutting machines for metal, don't worry. It is a super simple build that doesn't need any expensive machines like a lathe or a CNC machine.

If it turns out to small for you you can always size up each piece, though it may be difficult to get large sleeve bearings.

Supplies

These are all the parts that you will need minus tools and adhesives (I got most of my materials at Ace Hardware):

Two 3/8" hex bolts, any thread, at least 1.5" long
K&S 0.064 in. x 1/4 in. W x 12 in. L Brass Metal Strip
Four 3/8" x 7/8" x 1/16" metal fender washer OR four 3/8" x 1" x 1/16" metal fender washer (I used the first one)
A black sharpie with an ultra fine tip
3/4" x 1" x (At least 1") bronze sleeve bearing (inner diameter X outer diameter X length)
3/8" x 1/2" x (At least 1") bronze sleeve bearing (inner diameter X outer diameter X length)
1/2" x 3/4" x (At least 1/2") bronze sleeve bearing (inner diameter X outer diameter X length)

Step 1: Make Sure You Have the Tools Necessary

For this project I used a coping saw and a hack saw both with metal cutting blades, along with a file, a drill with a 3/16" drill bit for metal, and super glue or other metal adhesive.

Step 2: Making the Number/Letter Wheels

In order to make this part your going to need the 3/4" x 1" x ~~ bronze sleeve bearing, the 1/2" x 3/4" x ~~ bronze sleeve bearing, a hacksaw, a file, and superglue.

Repeat the process below 3 times:

(Inner Ring) Cut a ring of the 1/2" x 3/4" x ~~ bronze sleeve bearing about 1/8 of an inch long. Then cut a piece of the circle out about 3/16" wide as shown in the picture above. After smooth the inner side and edges with a file to make the movement between the ring and the inner mechanism have less friction.

(Outer Ring) Cut a ring of the 3/4" x 1" x ~~ bronze sleeve bearing about 1/4 of an inch long. Mark lines with sharpie on the side spaced about 3/8" inch apart to mark where you will cut. Now on the outer side of the ring cut about 1 millimeter in depth. You can then color the cuts in with sharpie like I did but you don't have to. I personally prefer it with the sharpie because is stands out more.

(Combine) Lay the smaller ring on a table and press the larger ring over it so one of the areas in between the cuts on the larger ring line up with the cut out in the smaller ring. Make sure both pieces are touching the surface of the table. On the inside put a couple of drops of superglue to hold the two rings together.

Step 3: Making the 1st of the Two Main Body Pieces

For this piece you will need the 3/8" x 1/2" x ~~ bronze sleeve bearing, two 3/8" x (7/8" or 1") x 0.4" metal fender washers, a 3/8" hex bolt, a hacksaw, a file, and superglue.

(Making the pieces) First take the 3/8" x 1/2" x ~~ bronze sleeve bearing and cut a piece a little more than 3/4" long. Lengthwise cut out a piece about 3/16" wide. File the outer side just a little to make it easier to turn the number/letter wheels when you put it together. Next take the 3/8" hex bolt and cut of the top.

(Putting it together) Superglue the two washers together and then glue both the top of the hex bolt and the sleev bearing on either side of the two washers as shown in the picture above.

Step 4: Making the 2nd of the Two Main Body Pieces

For this piece you will need one fender washer, the K&S 0.064 in. x 1/4 in. W x 12 in. L Brass Metal Strip, a 3/8" hex bolt, a hacksaw, a file, a sharpie, superglue, 3/16" drill bit for metal, and a drill.

(Prepare the hex bolt) First take your hex bolt and cut it down so the screw section is 1" long. Then hollow out the center with the 3/16" bit and a drill. Make sure to go as straight as possible so you don't go out the side. This is where you will keep your valuables... Air? It doesn't really fit much at all but it still turns out really cool in the end. Then choose one of the six sides of the top of the bolt. Draw or cut a line across it in the direction the screw is going. This will be how you will align the number/letter wheels to open your mini safe. Then on that same side use your file to slightly flatten the threads to make it easier to glue the teeth on later.

(Making the teeth) Take the brass strip and cut a 1" piece of it of. Then lengthwise cut about 1/2 of the strip off so you are left with the other 1/2 of the strip. Then take a sharpie and color in as shown in the picture above. Use a file and file the side down until you can't see the sharpie anymore.

(Putting it together) First glue the washer to the head on the screw side. The on the side with the flattened threads, glue the teeth strip on with the side with the tooth on the end on the end of the screw as shown in the picture above.

Step 5: The Final Piece

For this piece you will need one fender washer, a sharpie, and a file.

(Cutting the notch) Color the area where you will file out the notch with a sharpie on the edge of the center whole. (3/16" x 3/16"). Then simply like the teeth in the step before, file out the section with sharpie on it.

Step 6: Putting It All Together

For this step you will need all of the previous pieces you made, a sharpie, and superglue.

(Putting it together) Take the piece you made in step three and the number/letter wheels. It is very important that you put the wheels on in the correct direction or it will not work. Take the first wheel and slide it on the cylinder with the side without the inner ring in first. The side showing should be flat as shown in the picture above. Repeat with the other two rings. Then glue the fender washer with the cut out so the cut out aligns with the cut out on the cylinder.

(The combination) To make the combination line up the wheels so that their cut out matches up with the cutout on the cylinder. Then choose how you want the combination to work weather its a three number/letter combination or six number/letter combination. I did a six letter and number combination and my code was the word puzzle. Use a sharpie to fill in the code. Then fill in the rest of the places, just make sure to don't repeat the same thing twice because then you might not be able to figure out what the correct combination is.

(How to close it) Line up your combination with cut out and slide the other piece in and then scramble it.

(How to open it) Line up your combination with the line on the top of the hex bolt that will slide out and slide