I was walking around the house, searching for ideas to make something out of cardboard, and as I was looking I was hitting my hand against the end of a cardboard tube. It made a neat sound, which got me thinking...

If I cut cardboard tubes to different sizes, would they make a noticeably different sound when striking them? Yes, they do!

In this instructable, I will show you step by step of how to make a cardboard tube xylophone.

Instead of embedding a few second videos on every step, I made one longer video- this shows the steps (with pictures), but the directions go more into detail and have pictures for each individual step.

Here’s a link to the video:
https://youtu.be/tnnP-Q1W17I

Supplies

Tools:
Box Cutter
Swiss Army knife (or scissors)
Tape measure
Ruler
Pencil (or pen, or marker, etc.)
Duct tape
Glue Gun (and glue stick refills)
Drill with a hole saw bit (optional, but it sure does help)
Paintbrushes
Nail file (optional)

Materials:
Cardboard tubes (or one very long one!)
Cardboard (boxes or flat sheets)
Paint (acrylic works well)

Step 1: Materials

First, you need to rustle up some materials! Thanks to my grandpa (who is always building something), I have a couple of about eight feet long cardboard tubes. These are the actual instrument part, so thick and sturdy tubes will do better than flimsy cardboard.

Step 2: Cut Cardboard Tubes

After you get all of your materials together, it is time to cut the tubes to different lengths. I decided to use eight different sized tubes, to get as close as I could to a full octave. Remember, the shorter the tube, the higher the sound; the longer the tube, the deeper the sound. I decided to go from five inches to twelve inches (one inch intervals), but that could be altered based on preference. (If you have any suggestions, please put your ideas in the comments!)

I used a Swiss Army knife to punch holes in the cardboard tubes (the tool is called a reamer), and then I used a pocket knife to finish cutting the tubes. My brother informed me that cutting cardboard is not good for a knife blade, so your best tool for cutting cardboard is a box cutter. If you don’t have either, scissors can be used, but your cuts probably won’t be as clean.

Here are are all of the tubes lined up, from highest to lowest pitch. Next you will make the stand to hold the tubes (the instrument body).

Step 3: Measuring- Evenly Space the Tubes (Optional)

This step is completely optional (you can just eyeball it if you want), but it helps to find out at least how big to make the instrument body (and it will help you evenly space out the tubes). Measure the diameter of your cardboard tubes you used. I traced a tube to make it easier. When you measure your tube (in my case 1 and 7/16 inches), multiply that by the number of tubes you have (in my case eight). Record that number (11 and 1/2 inches). Now you have to decide how much of a gap to put between each tube. I went with two inches. Remember to leave room at the edges. If you want the cardboard tubes to be evenly spaced and have room at the edges, multiply the amount of space you want in between each tube by one more than the number of tubes you have. (2” * 9 = 18”) Take this number, and add it to to number from earlier. (11 1/2” + 18” = 29 1/2”) Here is a picture of all of the tubes spaced about two inches apart.

Step 4: Find/Assemble Your Box

When you find out how big your instrument needs to be, find a box that fits that size! I happened to have a box that was almost the exact size that I needed. But as usual, I ran into a problem. Part of the box was missing, so I made a shape to fit the other side. It would have been simpler to find a box that was already well, a box, but what fun would that be? After taking apart a piece of another box, I attached it inside of the original box to make one solid structure.

If you begin with one solid box, you’re good! But you will want to cut out some spaces in the sides so you can hear your instrument when it is played.

Step 5: Instrument Body- Cut the Holes

This is completely optional too, but if you’re like me, you will want everything centered, so measure the length of the body. (Mine was 32 3/8 inches). If you decided to do the step where you figured out how long your box needs to be and you did an exact sized box based on that, you can skip this step! If your box is a little longer like mine, here is what you need to do. Take the length of your body (32 3/8”) and minus the length of how big you decided it needs to be (29 1/2). (32 3/8” - 29 1/2” = 2 7/8”) Take this number and divide it by two to decide how far you need to measure in on each side to center your tubes. (2 7/8” / 2 = 1 7/16”)

Step 6: Instrument Body- Cut the Holes

Now that you have all of your measurements figured out, you can draw these in pencil on your box to help you cut the holes (write in pencil so you can erase if you need to). After accounting for the space you need at the end, alternate back and forth between the space between your cardboard tubes and the the space for your cardboard tubes. The video will explain the process a little better.

Now that you have everything ready, it’s time to cut the holes! I used a drill with a hole saw bit, but if you don’t have one of those you can draw circles and cut the holes with a box cutter. (Thanks to my brother for videoing this step.) After doing this I cleaned up the tops of the tubes and the holes in the body with a nail file.

Step 7: Insert Tubes and Glue in Place

It’s time to insert the tubes! When I shoved them down inside far, they didn’t make much sound; but when I pulled them up almost completely, they made a good amount of sound! (If you have a suggestion how to do this better in the future, please let me know in the comments!) Insert them in about a quarter of an inch, and then glue them in with a glue gun.

After you glue the outside, glue around the outside of the tubes inside the body.

Step 8: Decoration

Now technically, you’re finished. But why does it look like it’s missing something? Decoration! (Before you decorate, make sure you erase your pencil lines.) You can decorate it any way you like, but I decided to go with primary colors. I did a base coat of white first, because if you don’t the colors are dull (because the cardboard is dark).

After you decorate it (or don’t), you’re finished! Congrats! Now you have a homemade xylophone. :D If you have any ideas or questions for me, please let me know in the comments. This is my first instructable, and I’m sure I have a lot to learn. Until next time!

- MW Art