First of all you need to get a material for cajon. Even professional ones are made of plywood, so this material is good to go with.
Second step is to choose the size of cajon. This musical instrument is supposed to be seaten on so it should be comfortable. I decided that it’s dimentions will be 330x330x450 mm.
The main frame should be made of 10-12mm thickness plywood. And the percussion panel (front one) should be thinner, about 5 mm thick. We cut all 6 panels with electric fretsaw. In back panel you need to do an openning, round form is classical.
Some people make a wood framework to connect panels. I decided to glue them and than to screw. Firstly I connected all 10 mm thick panels.
And now the most difficult part comes. It is to create rattletrap sound. The most effective way is to use drum tailpiece.
To get a rattletrap sound you’ll need to make it vibrate of every hit. So the best way is to cut it in two equal halves and fix it close to the percussion panel.
To keep it in precise position you need to fix it hard on any beam that can be put in special brackets. We made brackets of plywood panel again by cutting out an equal grooves in each piece.
Than all you need is to srew the drum tailpiece halves to a beam.
Then to fix brackets in a frame of cajon close to the front surface.
Now you can srew front panel to a cajon box and put the drum tailpiece inside.
Have some music!