Watch this video first! This is an introduction to the idea of this spring-joint box. I show a rough prototype and discuss what I want to change in the final design. The box is made of 1/4" walnut for the sides, and 1/8" quartersawn sycamore for the bottom and lid of the box. (Actually, my sycamore is almost 3/16" thick. You might have to adjust the design for the exact measurements of your material. See my note below about the bill of materials listed in this project.) The whole project incorporates profile cuts, slotting, and engraving techniques.
The idea here is that the hook tabs on the long sides fit through slots on the short sides when bent down, and then they spring back when pushed through the slots. This holds the box sides together nice and tight. The sides also fit into groves for further stability. The box bottom is fit into a groove slot all the way around all sizes, so it is also held fast. The lid is in a similar groove slot on 3 sides, and one of the short sides doesn’t rise up to the level of the lid, so it can be slid off. The design is very simple. The box is adorned with engraving on the lid, and on one side. I am using this as a gift box for a wooden bowtie, so my engraving reflects that. You can change it to whatever you want that fits your gift. This design is 6×3×3 inches, roughly, but could be adapted to larger sizes. Think wine bottle, rolling pin, whatever!
Note that in the bill of materials, I listed half-inch walnut, and 1/8" cherry. My box sides are actually 1/4 material, and I recommend using 1/4" material for the sides! Half-inch will be very hard to bend into place.
This step creates the long sides of the box. Here’s the easel project:
You need two of these, and they are identical. Cut from 1/4" material. I talk about the design in this video. Basically, it’s going to cut out a rectangle with two hook tabs coming out on each side, and with several little relieve cuts going in from each side. These gaps let you bend the hook tabs down enough to get them into the receiving slots on the short sides. You don’t want to have to bend them too far to break them, but you want them to be held tight when they are assembled. This whole action is a profile cut all the way around, and slot grooves cut across the bottom and top. These grooves will hold the bottom and lid of the box in the end. Note that the groove size is based on the exact thickness of your bottom and lid material. Just add one or two thousandths of an inch to that thickness to make it so they slide in nicely, but don’t fall out easily. Better to go a bit too small than a bit too large – you can sand down the thickness of your bottom and lid a smidge if the fit is too tight.
Get as clean a carve as you can here, because sanding in those relief cuts can be sort of a pain. Using a down-cut bit might help with this, especially in the grooves that don’t cut all the way through. I don’t have a bit like that, so I did a fair amount of sanding.
This step creates the two shorter sides of the box. THESE ARE NOT IDENTICAL! You have to create one side that is full-height, and then one side that is a little shorter. The short one is so the lid can slide on and off of the box into the groove. These sides have a good space for some engraving. I put a bowtie shape right in the middle of one of mine, and the easel project can be found below. Use a different image based on what you are putting in the box.
IMPORTANT: if you are engraving, you have to cut out the side, then turn it over and engrave your image on the other side. The original carve of the sides have the inside-face shown when done, but you want your engraving to appear on the outside of the box, so just flip it over, re-clamp it down, and engrave. Here are the Easel project files:
These carve a lot faster than the longer sides. You’ll see four slots on each side that go all the way through. Your hook tabs on the long sides will go through these. You’ll have to squeeze those hooks together to get them into the slot, but once through, they will snap into place nicely. The grooves along the top and bottom are for the bottom and lid of the box, and the grooves along the sides (that run right over the through-slots) are for the rest of the long sides to seat nicely inside. Profile cuts and groove slots again make this piece, and optional engraving (which I highly recommend doing – it really makes the box great!).
Once again, downcut bits will help keep the carve clean, if you have one. If not, this one is actually pretty easy to sand.
This is the simplest part. The box bottom is nothing but a rectangle of appropriate size, just a profile cut. The lid of the box is similar, but it has a hole carved in to be able to get the lid off with a finger, and I also engraved a catch-phrase in the box lid. This could be a different phrase, or an image, business logo, or whatever. Note that I cut mine from material that is almost 3/16" thick. My grooves on all the sides are designed to fit this thickness with just a tiny amount of tolerance. You will have to adjust the grooves if you use thinner material. If the lid or bottom fit is too tight, just go at it with an orbital sander or similar for a few seconds to fine-tune the fit.
Not much need here to worry about getting a clean cut. Nothing is easier to sand clean than a simple rectangle profile cut, and even the engraving will sand out with just a few strokes. Here are the Easel project links:
After sanding and cleanup, I just coated all the pieces of my box in Mike Mahoney’s walnut oil. You could use boiled linseed oil, tung oil, danish oil, lacquer, or your finish of choice. I like a satin finish that I get from walnut oil.
After the oil has dried, it’s time to put the box together. Do it like this;
1. Put one long side into one of the short sides. Put the bottom hook tab into the slot just a little, then pinch the sides of the top hook tab, push it down until it fits into the slot, then press them in. You’ll hear the sharp snap as they fit into place. MAKE SURE TO PINCH THE SIDES OF THE TOP HOOK SLOT, and DO NOT JUST PUSH DOWN ON TOP OF THE LONG SIDE. The very top tab on the long sides is the groove where lid will fit. The hook tab is actually below that. You will break the whole top section off if you push down here at this stage. Don’t ask me how I know! Once the box is all together, these tabs will be protected and installed into the grooves, so it won’t be so fragile.
2. Put the other long side into the assembly, same procedure.
3. Now your box has three sides, install the box bottom by sliding it into the grooves.
4. Install the other short side. You will have to do this one with all 4 hook tabs at once. Just put the bottom two into the bottom slots just like above, then one at a time pinch the sides of the other hook tabs, press them down and into the slot. Once all four hook tabs are just barely inserted to the slots, you can press the whole thing into place until they all snap. Make sure the box bottom works its way into the right grove. If it doesn’t, it might not let you get the sides pushed in far enough for the tabs to snap into place. Check out the video here – this happens to me, and I have to nudge the bottom into place just slightly.
5. Slide the lid into place. You’re done!