Mini Cajon With Tunable Snare!

Bored at home during the coronavirus outbreak, I decided to make a small cajon with what I had lying around to play along with my ukulele. Most of the tools and material can be bought at any hardware or music store and of course, online. Making a musical instrument is a craft learned over time, this first cajon I made doesn't sound amazing but I had fun and learned a lot making it.

I upcycled a wooden (bamboo) box I had been using for other things as a base. It was already well built and had holes for the sound to come out of. You can use any size wooden box and cut/drill holes as you please.

Materials (other than the box):

-Plywood (for the cover)

-Tuners (I had 90 degree tuners from a ukulele build left over)

-String (I used a guitar's spare E string but any metallic string will do, each will have different sound)

-Nails (small, to attach the cover)

-Screws

Tools:

-Drill and different size drill bits

-Pliers

-Cutter

-Hammer

-Caliper (useful, a ruler can do fine as well)

-Clamps (very useful!)

-Small screwdriver for the tuners

-Exacto knife

-Multiple grades of sading paper

Step 1: Prepare the Tuners

Assuming you have a finished wooden box after all the sanding, fixing and finishing you want, we can go directly to preparing the tuners. If not, Instructables has dozens of guides on how to make whatever box you choose.

After an online search and some consideration I decided to make the snares diagonally from the corners to the center across. There are two things I kept in mind while designing the parts that will hold the tuners: I wanted to keep the tuners hidden but accessible, and the string had to be press right up against the cover.

The first part, of which I made two copies, is the one holding the tuners. They are made of leftover pine wood, their size should be big enough for the tuner to fit on with some extra room for the peg. After deciding which way the tuner fits I measured and drilled a 6.5 mm hole for the peg all the way through. From the back side (the opposite side of where the tuner is attached) I expanded the hole to 8.5 mm, deep enough to create some room around the end of the peg. This wiggle room will allow the string to coil around the peg freely and not get cut off. Finally I drilled a 3.5 mm hole from the top to intersect the peg exactly at the hole on it's end. Insert the tuners and check that you can see the hole on the peg through the feeding hole you just drilled, turn the knob and see the peg spinning. If it looks good mark the holes for securing the tuners, drill small 2 mm holes so you don't crack the wood, and screw the tuners tight.

The second part is much easier. on this end you just have to drill two 2 mm holes in wood all the way through, just make sure not to drill them too close to the edge.

Step 2: Attach the Tuners

After sanding the parts roughly (since they're internal) they are ready to install. Secure the pieces in place with clamps making sure they are about 1 mm below the box's edge. Drill prep holes from the out side where your screws will go and secure the pieces in place. Make sure you aren't going to hit the tuners when you drill or insert the screws.

I decided one screw per part will do since the top will keep it from turning anyway. Make sure the screws are in deep enough so the box's surface remains smooth but be cautious not to crack the box.

Finally mark a small line with a ruler from the feeding holes in the direction of their holes on the opposite side, accordingly. Using an exacto knife and some sanding paper, give the string a smoother path around the corner when you wind it. Make sure the string will still touch the cover.

Step 3: Add Strings

Start by threading the end of the sting through the hole on the singular part and make a simple knot at the end. Tug it a little and hold it out to the corner. Cut enough string to reach the peg but not much more, you don't want too much excess string around the peg. Feed the other end through the feeding hole and turn the tuner, not too much, just enough so it's not loose.

I recommend sticking to a "Righty-Tighty" system, as in turn clockwise to tighten the string and vise versa. This will help you avoid confusion later.

Place the plywood on top to make sure the strings are right up against it.

Step 4: Close It Up

Cut your plywood to size. If you do not have a table saw, leave some extra space around as plywood chips easily, you can later sand that extra bit to get a perfect edge. When the cover is exactly the right size clamp it in place and observe. This step is the final nail in coffin ;) once the nails are in, it will be very hard to remove the cover. Take your time...

measure locations for your nails as you see fit, making sure to avoid the screws. I avoided the corners too as they were a weak point in my box. Instead I made sure there are nail about 3-4 cm on both sides of the corners.

Drill 1 mm holes in your marks as deep as the nails you are using, otherwise you are likely to crack your box or bend the nail part way through. Make sure you are drilling as perpendicular a possible, you can see in the picture where my hole burst through the outside forcing me to drill a new hole near it.

Slowly hammer the nails all the way down, so the surface of the cover is completely smooth when you run your hands along it. Now you can start tuning the string to your liking, tight enough to avoid a harsh buzz but not too much so that you can't hear the metallic sound at all. Now go ahead and jam on, explore your new cajon and the different sounds and beats you can make with it.