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How To Build a Cajon - Gluing |
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Written by Casey
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Friday, August 14 2009 14:43 |
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Page 5 of 12
  Gluing the frame together using the elegant custom clamping/roping techniques that my paltry toolset affords. A good time to make sure everything is straight, 90 degrees, etc. No nails used in the cajon, just glue. Given the way the boards meet, it's plenty strong enough to hold the player.
  Gluing the frame into the cajon. Due to slight errors in measurement and cutting, the frame pieces were a bit short; thus slivers of hickory were inserted to fill the gaps when the gluing was done. Note the custom clamp improvisations and the stacked wood and old paint can for bracing ( tip: pink is usually the heaviest). Clamps would have been a lot better and easier, obviously. The image on the right shows the back side, where the door will be. Only two hickory pieces are required there. Hopefully it can be seen that the door will set flush against those two pieces and the two edges of the side walls. The overlipping top and bottom prevent shearing stress on the hinges from the player sitting on the cajon.
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Last Updated on Thursday, April 08 2010 16:01 |
Re: wood, see page 3, called, cleverly, "Wood and Frame": http://caseyconnor.org/jl/cajon?start=2 -- As far as species of wood are concerned, I doubt it makes much difference, since we're talking about laminate plywood here.
Re: Ocana, see the intro page, "Germán Ocaña".
Hi -
For the tapa, see page 3, called, cleverly, "wood and frame": http://caseyconnor.org/jl/cajon?start=2
For the snares, see page 7, called, cleverly, "snares": http://caseyconnor.org/jl/cajon?start=6
Good luck,
-Casey
@Job - see http://caseyconnor.org/jl/cajon?start=3 for info about the hole size issues. The size doesn't seem to matter so much, in my experience. The function of the hole is to "let the bass out", in a simple sense; the cajon "kick" sound is making a "thud" wavefront. Without the hole, the thud hangs out inside the box and doesn't come across as loudly. My personal conviction (as explained at that link) is that the hole isn't part of a "Helmholtz" model, where it "tunes" an air spring, so much as it just prevents the air pressure of the internal space from preventing the tapa from moving and allows the thud wavefront to escape. If the tapa vibrated like a traditional drum head membrane, then the hole might be relevant, as when playing a djembe you can insert or remove a fist in the hole to change the pitch of the drum.
Gluing/nailing: see http://caseyconnor.org/jl/cajon?start=4 -- nailing or screwing into the edge of standard laminate plywood doesn't really work, so you basically need to glue. Ocana also recommends this for the sake of a good air seal via the glue. The exception, sometimes, is the tapa, which you screw into the frame (the frame is in turn glued to the inside of the plywood). Some people also glue the tapa, but i prefer to leave mine removable.
@Richard - Yeah, generally the back panel is the same as the sides, with 12mm or thicker plywood (glued all around). It's important that the cajon be sturdy/rigid. Regarding the snares, see http://caseyconnor.org/jl/cajon?start=6 ... I agree that the string-snares are not satisfying. There are a number of other ideas on that page, as well as links.
Glad the site is helpful,
-Casey
My original design borrowed your first snare idea, but across one corner only thinking that I could have a 'slap + snare' corner plus a 'slap only' corner. The snares were not very successful: if given a lot of tension they produced a distracting sort of hum. Now I have them slack and with a few loose wires wrapped around which is OK played lightly but I am working on alternatives and will post here if I have a breakthrough.
I did find that there was a nasty resonance from the back panel even though it was well screwed on, and cured that by using frameseal (the stuff that goes around window frames) applied from the inside (with the Tapa removed). I also glued a chunk of MDF to the inside of the back panel to deaden it. The bass seemed more solid after that.
Just for fun, we put an ordinary cheap PC mic inside it and played it through a computer sound card: if you want to hear that, and see the cajon, go to youtube.com/expertanswers.
Even without a microphone I am amazed at the range of sounds and dynamics you can extract from what is just a box.
Thanks
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I am thinking about building my own canjon and your experience will be very helpful I think! Can't you create a blog or something like that and share your experience? I'm sure there is many people that will appreciate!
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Yeah same here!
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-Casey
Like i said am not a pro or anything else but love the sound of this instrument.
The one i built is 18 inches tall by 12 inches wide. i did not install any type of resonating devices in it, just pure sound from what the tapa (face) would make.
I use it for the first time today at church, like i said am not a pro, but i got good results.
Thank you for all the vital information you have share with everybody else.
Thanks