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I want to create a grid out of thin wood bars (slats?), where the slats cross each other on the smaller side, like in this sketch: Wooden grid

I would install LEDs in this grid, so it doesn't need to carry any external weight and the wood slats can be pretty thin. The grid would have a height of about 3-5 cm (1-2 inch) and a length of 50cm (20 inch).

I was thinking about sawing in the slats half way so I can stick them into each other: enter image description here

What is the best way to do this? I was thinking about using a saw blade that is wider than the slats are thick – so each time I would just have to saw in once and that would be it. Obviously I would need pretty thin wood slats in that case (a few millimeters of MDF maybe?). Is this possible? Feasible? I have access to a chop saw and a buzz saw (both currently have blades not wider than 2mm) but I'm new to woodworking.

Is this even the best way to create such a grid?

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    Multiple good Answers already so I won't add another one but just to mention something that somehow got omitted from all of them, this is a type of half-lap or halving joint, sometimes referred to specifically as a cross-lap or cross-halving joint. – Graphus Dec 21 '15 at 13:53
  • Are you planning on putting a diffuser on top or leaving the grid bare? BTW off topic but if you rip apart an old flat panel display there's some awesome diffusion lenses in them. And it's free if you have an office building with a dumpster nearby ;) – Jason C Dec 21 '15 at 16:04
  • I don't know the answer to your question, but what software are you using to produce those drawings? – Tom Dec 21 '15 at 16:19
  • @tom Looks like sketchup. – Jason C Dec 21 '15 at 16:22
  • @Graphus: Thanks, I'm not a native English speaker so this really helps! And yeah, it's ineed sketchup – florian h Dec 21 '15 at 21:34
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Yes, this is a great way to make such a grid, although you want the joints to be as tight as possible vs. cutting the slots slightly wider than the slats. With a looser fit, the grid will be more prone to racking.

If you want to make a cut to exactly the right width in one pass (up to a limit), you can use a dado set (available in either a "wobble" blade or the more common stacked dado set) to cut to the exact width of your slats, and the blade set to exactly half the height of your slats. Keep in mind that on a 10" table saw, the common dado set sizes are 8" and 6", which will limit your depth of cut.

Ideally, you would use a crosscut sled on a table saw with several slats aligned and clamped together.

You can also use a radial arm saw with a dado set--it works in a similar fashion but you cut from the top instead of the bottom, and the blade moves instead of the workpiece. You have to be especially careful since a radial arm saw is configured to make a climb cut.

If you have a sliding miter saw, you can work similarly to a radial arm saw, but the blade cuts as you push it back instead of as you pull it toward yourself. As far as I know, no sliding miter saw is designed to be used with a dado blade of any kind, so cutting the slats on a sliding miter saw will require multiple passes to cut the width of a slat, unless working with very thin material.

  • I decided to use a sliding miter saw where I clamped multiple slats together and made two cuts for each slot. It took much less time than I anticipated (about 30 minutes with a helping hand for 16 slots in 32 slats) and it turned out great. I didn't use a dado set as they are forbidden for professional use in Germany and therefore are really expensive. – florian h Jan 11 '16 at 11:28
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For what it is worth I have also made something like this. I fitted an old flute case with partitions to hold my collectible playing cards. At this time I did not own a table saw so it was not considered among my options. I used a scroll saw with success but I found it time consuming in hindsight. Given the availability of tools at your disposal it is worth considering but it shouldn't be your first choice.

Card Box

Using 1/8 inch MDF/hardboard/millboard/paperboard and a table saw would be the most efficient way to get this done. Typical blades (measure to be sure) kerf is 1/8 of an inch to little to do other than measure and cut. A crosscut sled with stops would be ideal to get each cut the same.

I would add that your design would still be viable to move no matter how perfect you make your cuts. Wood that thin and designed as pictured would be sure to shear easy. I would suggest that you consider making the outside stock of something thicker to make a frame.

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Both the horizontal and vertical slats will be the same shape if your slots are halfway deep.

If you have a table saw you could use it to cut slots halfway deep in a larger board, e.g. imagine cutting horizontal slots in a 2x4.

Then once you have cut all the slots use the table saw to slice your slotted board into thin slats. Use a zero clearance insert or a sled. Watch out for kickback (or just aim your table saw in the direction of your pile of slats, heh).

This will minimize the number of cuts you have to make and also lets you cut your slat widths to whatever you want to match your slot widths. If your table saw blade is too narrow use a dado set or make multiple passes per slot.

You can keep the slots evenly spaced with a jig of some sort with piece of something on it that fits in the slot and is the size of one of your grid cells away from the blade. Cut first slot, then place it over the tongue piece and cut the next, and so on to get quick evenly spaced slots.

Alternately, like rob's answer says, if you already have slats you can clamp or double sided tape them together to cut the slots with a table saw in all of them at once, as with cutting the pre-sliced board above. The same slot spacing jig can be used if you do it this way, too.

With appropriate clamping the latter (cut all slats at once) could be done with a buzzsaw, you'd have to be creative if you wanted a spacing jig. The former (slot board then slice slats off) would be a bit trickier.

By the way I would err on the side of cutting your slots slightly too deep rather than too shallow. Slightly too deep you can still create a nice flush grid and glue will still hold fine. Slightly too shallow and you won't be able to stick your horizontals and verticals together without recutting. Make test cuts first!


By the way if you do cut your own slats and you are leaving the grid bare, another thing to consider would be gluing a thin piece of some other kind of wood to the top and bottom of your board before slotting and slicing, if you want a nice contrasting trim on the edge of the slats.

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When I have made such crate creations, I have resorted to 1/8" (3mm) thick material either masonite (press board) or baltic birch plywood. First I cut the material into to strips then used my radial arm saw with a more or less standard thickness blade of 1/8" which yields a nearly perfect fit.

Of course the answer to your question of how to best accomplish the task is dependent on what tools you have at your disposal.

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