How to Build a Cajon Drum With Adjustable Snares

Mike’s Guide On How To Build A Cajon Drum

If you prefer to do things yourself, building a Cajon might be just the thing for you! Unfortunately many guides around the internet are unprofessional, leave things out and have plain bad advice! I’ll walk you through everything you need to know in as much detail as I can. In this guide, I’ll teach you to build a typical snare-cajon perfect for acoustic performance!

Here’s a demo of the final product:


First of all, I’ll give you some realistic expectations:

Estimated Cost: $50 USD
Estimated Time: 4-5 hours

You’ll need:

Tools:

  • Saw capable of cutting plywood precisely in a straight line
  • Saw or circle cutter for cutting a sound portal
  • Ruler + Pencil for marking
  • A square or another 90 degree angle to square your corners
  • Drill (Will find the gauge for the bit soon)
  • Screwdriver

Materials:

  • In this project we will use Baltic Birch plywood
    • Two 1/2″ by 12″ by 18″ pieces for the two frame sides
    • Two 1/2″ by 12″ by 12″ pieces for the top and bottom
    • One 1/2″ by 13″ by 18.5″ piece for the back.
    • One 1/8″ by 13″ by 19″ piece for the playing head or tapa
  • Four 1″ x 2″ x 11″ pieces of pine lumber for reinforcing the frame
  • Wood Glue
  • Teak Oil or the finish of your choice
  • Small brass screws for the front plate
  • Optional Snare Materials
    • One half of a 20-strand snare wire, from a snare drum
    • Mounting the snare will be covered later on

Notes on wood selection:

Baltic birch is used in most store bought cajons for it’s strength and lack of interior cavities. I use it in my entry-level cajons for that reason. Some people argue that solid woods make better sounds than plywood, but I haven’t decided just yet. I do know they’re much easier to work with and will probably last longer. That’s why my “professional level” cajons are all made of solid tonewoods. Here’s a link to my article on the subject of solid wood vs. plywood.

Step 1: Cutting the Wood

Cutting The Wood

Tools

These are the basic tools I used to cut the plywood.

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Mark 1 foot from the edge in several places.

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Then connect the dots. This is the line I will cut down.

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Here, the board is mounted and ready to cut

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When you begin a cut, make sure you follow the exact center of the line. These will have to be squared off at some point. It’s much easier to cut a straight line than it is to fix a crooked one! Also, this is a sweet saw.

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I’m about to cut the top and bottom of the cajon.

We’ll begin by cutting the top and bottom of the drum. I’m using a 2′ by 2′ piece of plywood, so I’ll cut it into four 1′ by 1′ pieces. Start by marking 1′ from the edge in several places. After than, connect the marks with a straight edge to form the line you will follow as you cut. Include in your measurements the sliver of wood that the saw removes. My saw takes about 1/16″ of an inch away from the measurement and my 12 inch sides became 11 15/16ths inch sides.

 Take a piece of scrap wood and use it to protect the good wood when you clamp it into place to cut. Mounting the wood really helps keep the lines straight. If you can’t get a clamp, find someone to help you hold it in place!

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Here’s an out of focus shot of me comparing the two pieces. If the line up, good, you can start cutting the sides! If not, sand them until they’re the same size and completely square.

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If you need to sand two pieces, clamp them like this…

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…and use a sander on them.

Okay, now you have two 1 foot by 1 foot pieces of plywood. Good! Now you’ll need some sides! This cajon will have two sides that are 12″ by 19″. The back piece will be 12″ by 20″.

Cutting The Wood Continued

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Moustache the cat came over to inspect the wood.

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I’m cutting the wood down to size. This piece will make four 12″ X 20″ side pieces.

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Here are the two side pieces cut out.

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I’m about to cut the back piece. This piece is bigger than the others because it will be flush with the top and bottom. The two sides rest on top of the bottom piece and support the top. The back will be glued onto the drum.

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Here’s the back. What a pretty piece of wood! The ugly knot will be on the inside of the drum.

Now you should have a top, bottom, two sides and a back piece. Next, we’ll cut the playing head, or tapa. The tapa should be built out of 1/8″ plywood. You might have to search around for wood this thin, but thicker wood is a lot less responsive and resonant. The tapa should be the same size as the back. In my case, 12″ by 20″.

The tapa is scary to cut. The wood is very thin and you have to be careful not to crack it. Don’t worry, once it’s mounted on the drum, it will feel a lot less flimsy.

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Here’s the tapa! I cut it just a little bigger than I needed because I was worried about splintering. I’ll sand off the excess.

Step 2: Reinforcements

Now that all the sides are cut, we can start cutting the reinforcements. These are made of pine and help increase the surface area of the joints. Take a 1″ by 2″ length of pine and cut four 11″ pieces out of it.

Reinforcements

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The reinforcements will not touch the tapa or the back of the drum.

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Lay these pieces out on the sides of the drum, like so:

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Next, glue the pieces into place. Make sure to spread the glue around evenly. Use enough glue to cover the entire surface, but not so much that the wood “swims” in it. Make sure to wipe up the excess glue with a paper towel

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Next, I take one side, flip it over and put it directly on top of the other. The reinforcemnts should be pressing on each other. Make sure the reinforcements are exactly in line with the edge of the sides.

Step 3: Building The Drum Box

After you’ve let the sides dry overnight you can begin gluing them on the base! Once again, make sure everything lines up before you let the glue dry!

Gluing The Frame

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Make sure the sides make a perfect square with the base! Here I am using another cajon to check my alignment

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Without waiting for the other side to dry, I add the second side

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Now I glue on the top piece. Notice how I’m using square objects to square up the sides and an amp to “clamp” the joints down. While this method works, you’re going to be better off using clamps if you have them.

 

 

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Make sure everything is perfectly level and aligned before the glue dries! This is your last chance to fix any problems you might have!I allow for a tiny bit of overhang on all my edges so that I can sand them down once everything dries. You can always sand off an overhang, but you can’t add extra wood in a spot to fix a mistake!

Now you get to wait another night! Here’s the result:

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Congratulations! Hopefully it’s starting to look like a cajon now!

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Next, you’ll need to sand any overhangs you might have. There’s usually some glue to clean up too.

Step 4: Cutting The Sound Hole

Before we glue the back on the drum, we need to cut a hole. Now, there’s a lot of math that goes into calculating pitch and sound hole placement. If you want to get into that, check out my page on sound hole placement. If you want to just take my word for it, we’ll need a hole approximately 4.25″ in diameter. This should give us a resonating frequency of 81 Hz on the bass note. That’s a good range for a bass drum on a drum kit. We’ll place the hole slightly above center on the back of the drum. This position will help reduce feedback in the chamber.

I started the hole with a circle cutting drill bit and followed up with a jigsaw.

Cutting The Hole

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This flower cup just happened to be exactly 4.25″ in diameter. Carefully trace your circle.

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Begin the initial hole with your drill

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Next, trace around the line with your jigsaw.

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This is a terrible circle, but don’t worry! I can fix it up with a little dremel work and some sanding. It will look nearly perfect when I finish.

Step 5: Attaching The Back Piece

Next, we can glue the back piece on the drum. This process is pretty straight forward. Just make sure the edges are all perfectly flat and you apply enough pressure to make a good seal with the glue. Any unwanted air leaks are bad for the sound.

Gluing The Back

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Start with the cajon on the ground, like this.

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Glue the back in place

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Now apply lots of pressure and wipe up the excess glue.

Step 6: Attaching The Tapa

Next, you’ll need to attach the tapa, or playing surface. I used small, countersunk wood screws and drilled a hole every two inches, but keeping the corners open. I also skip a screw on each of the sides for more of a “slap” tone.

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In this picture, I am in the process of attaching the tapa.

Step 7: Final Sanding

Once the tapa is attached, you can finally hear your drum! Hopefully it has a great bass tone and crisp slaps! Next, round off all the edges with your sander. The goal is to make the drum comfortable to play. This step is fairly self explanatory, just make sure not to sand through the laminate!

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Step 8: Attaching The Snares

Now, we can start on the snare assembly. This snare assembly in full detail is on my simple snare mechanism page, but it basically looks like this:

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 Step 9: Attaching The Rubber Feet

Now, drill some small holes for the rubber feet. Mine needed to be nailed into position. Drilling a hole first prevents splitting.

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Step 10: Finishing The Drum

After that, you can begin finishing the drum! I prefer an oil finish. Make sure to finish the tapa and drum body separately. You don’t want the tapa to bond to the frame.

And here’s what the cajon looks like finished!

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By Mike Quain