Introduction: 3D Printed Astronaut Keychain (How to Make an Existing 3D Print Into a Keychain)

This instructable will be outlining the steps to make an existing 3D print into a keychain!

The 3D print I used was an astronaut with a boombox. If you would like to print this design, you can download the .stl file from Tinkercad at

Step 1: Materials

For this project, you will need:

1. Acrylic paints (I used Waverly because it is multi-surface, had a wide array of colors, and was inexpensive)

2. Paintbrushes (Preferably fairly small as the keychain will not be very large)

3. Nail file or sand paper (May not need this if your print isn't printed on draft quality)

4. Keyring (You can buy several of these in the craft aisle at Walmart)

5. Small 3D print (Mine is an astronaut with a boombox, but you could follow most of these steps for any small print.)

6. Sharpie

7. Lighter

8. Small needle (You can buy a pack of needles with several sizes in the craft section in Walmart)

Step 2: Remove Supports and File

If you have not removed the supports from your print, do that now. If there is any small portions of the supports that are sticking and not removing easily, use either eyebrow tweezers to grip it and pull it off, or like me, use nail clippers to VERY CAREFULLY clip it off. In my case, there was a small amount of supports still connected to his hand.

After you have removed the supports, if your print was printed on draft quality like mine, it is likely very rough in some areas. To help remedy this so it will be easier to paint and look much smoother in general, grab either a nail file or some sand paper. Sand paper would likely be the better alternative, but I did not have any on hand. If you do not either, the emery board of a nail file should work nearly as good with a little more work. Using the file, sand down any areas that are rough after the removal of the supports, being careful not to push so hard something breaks off.

Step 3: Paint

Now that your print should be a little smoother, it is time for the fun part (at least in my opinion). Get out your acrylic paints and paintbrushes! I chose three colors: silver, gold, and a sparkly black in order to somewhat capture the space theme. However, you can obviously choose whatever colors or quantity of colors you desire.

Paint the print however you want it to look using the acrylics and small paintbrushes. You will likely need to do about 3 coats of paint to get the colors looking fairly opaque, but if you like the more translucent look, feel free to use less coats.

If you are painting the 3D print of the astronaut with a boombox like me, I used the silver color to paint his whole body except for the square on his chest and the boombox. I did a couple more coats to make it more opaque, and then I let the silver dry. Then, I used the gold color to paint a circle on the front of his head (over the silver) to better resemble the astronaut helmet, to color in the square on his chest, and to fill in the circles and rectangle on his boombox. Finally, I used the sparkly black color to color the rest of the boombox and to outline the circle I made on his helmet. If you are having trouble accurately outlining like I did, draw the outline with a sharpie first and then go over this with the paint. Check to see if there are any areas that need another coat, and add it carefully.

Let the print dry.

Step 4: Create the Hole

In Tinkercad (or any other software compatible with 3D printing), you can add a small hole to your design before even printing. However, as I did not know I would be making this into a keychain when I printed it, I had to find a way to modify the design after printing. So if you already added a hole to your design before printing, you can skip this step. If your hole for some reason did not print or you already have an existing print you want to turn into a keychain, this step will be necessary.

From your pack of needles, choose the one with a point large enough to make a hole a key ring could fit through but not too large that it breaks your print. I chose the number 4 needle in the pack I had shown in the picture. Cover the base of your needle where you grip it in a paper towel (or anything else to keep from burning your hand) as the needle will get very hot in a moment. Flick on your lighter, and place the point of the needle in the flame until it turns slightly red. If you are afraid you are not coordinated enough to do this safely, get someone else to hold the lighter for you while you put the needle in the flame.

Once the needle is fairly hot, place the point at the place on your 3D print you would like a hole. In my case, this was the astronaut's free hand not holding the boombox. Press the needle through this point to the other side. It should go fairly smoothly; if it doesn't, reheat the needle and try again.

Step 5: Put It on the Keyring

Now that you have a hole for the keyring to fit through, you can twist the keyring into the hole. You may have to slightly bend the keyring in order to do this, but it should be able to bend back to normal fairly easily once it is in the hole.

Step 6: Done!

You should now have a keychain from a 3D print that you can now place on your keys, hang from somewhere, give to a friend, etc.! Enjoy your new, functional keychain!