An All-Wood Grand OpeningComments (0)
This article is from Issue 3 of Woodcraft Magazine.
Create your own unique closing mechanism for that special wooden box or cabinet. Carefully cutting your own small parts and sanding them to a perfect fit is sure to be a pleasurable challenge.
Almost 15 years have passed since I first developed the opening/closing mechanism that has become a signature design element in my Art Tekno Deco jewelry box series. I was trying to devise a latch with no visible metal, as I did not want any hardware on these boxes. Work in this series is all one-of-a-kind. I have built many hundreds of design variations based on the original concept, and while the look can vary dramatically the underlying mechanics are based on the same original principle.
Now, before some archaeologist writes in to say he found a sarcophagus in one of the great pyramids with a similar closure on it, I’ll admit that the principle is so simple I’d be amazed if it hasn’t been used on something in the past. Let’s just say that in my 30-plus years as a professional box maker I have probably seen more jewelry boxes than Ivana Trump, and I haven’t found one of these latches yet.
Using common shop tools, I will show you how to construct one of these latches. Three things should be pointed out before you begin:
First, while you can use a lathe to create some of these parts, a lathe isn’t necessary (I don’t use one).
Second, it’s important to follow the fabrication and installation steps in the order presented to assure proper fit and alignment of the various parts. Keep in mind that the photos show some other design elements specific to my work, as they were shot during the construction of a commissioned box. While many other techniques go into the creation of one of my boxes, my goal here is to convey the construction methods for the basic latch.
Third, you’ll notice that I give very few exact dimensions here. This will give you the freedom to construct just about any size latch for just about any size box. That said, the pivot blocks shown in these photos are about 3/8" thick and as tall as the box lid is thick. Their length is determined by the size of your opening lever. The lever can be made from 3/4" x 1" stock, with the length determined by the combined height of the box, its lid, and wherever your cradle design positions the piston and cylinder. The cradle, if made from a solid piece of wood, is around 1" thick, 1" high, and 2" long. However, don’t be limited by these dimensions in any way.
And don’t limit yourself to boxes either – this latch would make a nice addition to any other project with a door or lid, such as a small cabinet, chest or even a clock case.
For your first attempt at making one of these latches, I’d suggest using a somewhat forgiving and easily workable hardwood. Mahogany and walnut are good choices. Most softwoods should be avoided, as the necessary sanding will make it difficult to maintain the rather precise fitting tolerances the mechanism requires.
The first step is making the cylinders. Choose a block of wood that will allow you to make at least five or six, just in case something goes wrong. You will be using a long plug cutter on the endgrain side and the block should be at least 1/2" taller than the depth of your cut, as you want the plugs to remain in the block for the next step. I use a cutter that makes a 1/2"-diameter cylinder about 3" long, but other sizes would also work.
If you slightly overlap these cuts to allow for sawdust exits, you’ll greatly decrease the chance of the cutter burning the wood. Clamp two pieces of wood to the base of the block. This serves two purposes: creating a more stable base for the whole cutting and drilling process, and preventing your cutter from accidentally hitting a clamp face. Always hold the block with a clamp as shown in Fig. 1, as large plug cutters exert a lot of torque and you don’t want that piece of wood spinning around in your drill press. Don’t ask me how I know this.
Drilling the holes
Be sure to mark the orientation of the block after cutting the cylinders. This will greatly increase the chances that the hole you will be drilling later will run true by drilling with the block in the same position as the plugs were cut. Don’t remove the clamped pieces of wood until after the drilling process.
Mark the center of each cylinder with a pencil (Fig. 2), and then lightly tap the mark with an awl. Don’t tap too hard or you may split the wood. Next, put a few drops of cyanoacrylate glue on the end of each piece to be drilled. The glue should readily soak into the end grain. Let it dry for at least 10 minutes, and the chances of splitting during the drilling process will be greatly reduced (Fig. 3). While common wood adhesives can be used for most of the construction of my boxes, I use cyanoacrylate – also known as “C.A.,” “super” or “instant” glue – quite a bit in building these latches. I’ve posted a rather extensive article on cyanoacrylate glue on my Web site at teknodeco.com.
Reposition the clamped block on the drill press in the same position as you did when you cut the plugs and drill, slowly, to a depth about 1/2" shy of the length you made the cylinders. If using 1/2" cylinders drill a 3/16" hole (Fig. 4). A sharp, high-quality brad-point drill bit will become your good friend here. Don’t worry if some are off-center; that’s why you made extras. Any that are just slightly off can still be used if the thin part is positioned at the bottom of the cradle that will hold it.
Working the cylinders
If you have a lot of ragged wood on the sides of the block from boring through the edges (which you should have, for sawdust removal), sand one side flat. Set your bandsaw fence a bit proud of the depth you cut the cylinders and run the block through; all your parts will fall right out (Fig. 5). Sand the ends of the hollowed cylinders flat on your belt or disc sander.
Next, you might want to make a simple tool to make finish sanding these parts a lot easier. Take a dowel slightly larger than the hole you drilled and sand a very gradual taper on it. Experiment until with just a bit of pressure and a slight twist it holds the cylinder firmly in place on the end of the dowel, as in Fig. 6. Because I make a lot of these, the photo shows some vibration-absorbing material glued on. Don’t sand more than necessary as you want this part to remain as close to its original diameter as possible.
Preparing the lid
Now proceed to the box lid itself for making and installing the next parts. Because the two pivot arms and the dadoes they mount into must be fabricated fairly precisely, the old rule of “cut a bit oversize and sand to fit” works well here. Choose where you want the latch positioned on the lid, and the width of both the pivot arms and the opening lever. Mark the location and width of the levers on the box lid, a little shy so you can sand them to a comfortable press-fit before gluing (Fig. 7). In this photo, to space the pivot arms correctly I’m using a piece of the same stock I’ll use to make the opening lever. If you plan to use “guide rails” on the box as I do (which isn’t really necessary), temporarily attach the top to the box for the next step. As I mentioned earlier, this particular box is being made on commission, and features all the regular touches – like guide rails – that I like to add. However, this article is specific to constructing a working latch mechanism, so I won’t go into details on additional touches like guide rails.
On the table saw make the inside cuts of the dadoes first, spaced the width of the opening lever. (If you’re adding guide rails, these first cuts will go through both the box lid and box body, as you can see if you jump ahead to the photo in Fig. 10.) If you’re not adding guide rails, make the cuts in the lid only.
Enlarge the dadoes for holding the pivot arms by whatever method you’re most comfortable with. I use a sliding table on my table saw, and then clean them up with a coarse-grit sanding stick. You could just as easily cut them with a straight bit on your router table, or even cut them by hand.
Pivot arms and lever
Fabricate the two pivot arms next. They should be long enough to seat in the dadoes and project enough to come close to the front edge of the opening lever. Tape them together and drill a 1/4" hole through both for the pivot pin near the lower front (Fig. 8). The location isn’t critical, but it should be approximately equidistant from the front and bottom edges. While still taped together, carefully sand the arms so their profiles are identical. Sand to fit, and using a snug-fitting guide dowel to maintain alignment, glue the arms into place. Make sure they seat flush to the bottom of the box lid as shown in Fig. 9.
Making the lever is the next step and is pretty straightforward. It should be long enough to reach below the locking pin and tall enough that it extends about 1/2" above where the piston will engage it. Make it a bit oversize; you can do final adjustments later. It should be sanded to have a loose, but not sloppy, fit between the pivot arms.
Locking it all in
The next step is to drill the hole to fit the locking pin. If you made the cuts for guide rails, center it between these two cuts about 1" from the top of the box body. As before, this is not a critical measurement. If you’re not using guide rails, place the lever between the pivot arms, making sure it is square to the body and lid, and draw lines down each side to mark its location. Then center the mark for the locking pin hole between the two lines, as in Fig. 10.
Drill the hole about 1/4" deep (again not a critical measurement). Put a dowel center in, position the lever in its intended location, and give it a light tap. This will give you the location of its receiver hole. Drill this hole and give it a slight bevel around the edge (I use a screw countersink bit). Fabricate a locking pin that will protrude about 1/8" from the box body. Unlike in some of the earlier cases where measurement isn’t critical, this one should be exact – if it is too long it will not disengage, and if it is too short it won’t lock the lever. Glue the pin in and before it sets, place the lever between the pivot arms, engaging the pin to ensure proper alignment.
When the pin is dry, locate and mark where the pivot pin hole will be drilled in the lever. I made a tool for this purpose by carefully sanding a shallow point on a piece of 1/4" steel rod, but a good hardwood dowel should work (Fig. 11). Drill the hole, reposition the lever between the pivot arms and see if it all fits. The lever will not move yet. Shaping its back profile, which will allow for that movement, is the next step. The hole in the lever should, once again, be a loose but not sloppy fit; enlarge the hole slightly if necessary. If the fit isn’t perfect you can glue a dowel in the improperly drilled hole, sand it flush, and try again. This repair will not show, as it will be hidden by the pivot arms.
Cutting a bevel on the back of the lever will allow it to move against the box lid. The back should be relieved to a point just above the pivot hole (Fig. 12). Locating it correctly is important, as it will also serve as a stop for the forward movement of the lever under its spring tension. You do not want it to move too far forward. This will make the whole mechanism sloppy when the box is open. Cut and sand it proud, and do the old “sand to fit” process once again.
After the lever has been cut to its final length the bottom back corner should be rounded off. This will allow it to slide over the locking pin so the box can be closed by just pressing down on the top.
Piston and cradle
Hang in there, you’re almost done! The next step is making a “cradle,” which will hold the cylinder and piston. Use your imagination when shaping it, but keep in mind that it must be anchored securely as it will get a lot of use and will be under constant spring tension. Before permanently attaching the cradle to the lid, slide it side to side to locate it so the piston will contact the back of the lever in its exact center. An example is shown in Fig. 13. Note in this photo and the next that I’ve added some decorative rings around the cylinder and piston.
After you’ve located the position of the entire mechanism, you have to determine the length of the piston, which is dictated by the spring you’ll be using. The piston itself can be made with a 3/16" plug cutter if you want a perfect color match to the barrel, or you can simply use any commercially available hardwood dowel. I use a medium-strength spring about 3/4" long, available at most hardware stores (Fig. 14). Place the spring into the cylinder, add the piston and once again use trial and error until you find a length that keeps good tension. Allow only enough travel of the lever for easy disengagement from the locking pin. The piston should be sanded to a loose fit in the cylinder to allow for inevitable wood movement with humidity changes.
Finish sanding and final parts adjustments for the entire mechanism can now be done, and you are on your way to making your first “Tekno Deco” closing contraption.
I know at first read this probably sounds more complicated than it is. After your first or second attempt you should be able to fabricate this interesting closing mechanism in well under an hour. I hope I have given you one more way to transform an ordinary box into something truly unique.
Hardwood blocks (mahogany or walnut)
Assorted hardwood dowels
¾" medium-strength spring
Plug cutters, #141009, $49.99 (three-piece set of 3/8", 1/2" and 5/8" cutters)
“Hot Stuff” cyanoacrylate adhesive, #08X21, $9.99 (2 oz. bottle)
Source: (plug cutters, cyanoacrylate glue)
Woodcraft Supply (800) 225-1153
William McDowell of Syracuse, N.Y., has been making high-quality, one-of-a-kind boxes and other items in his Art Tekno Deco series for more than 30 years. See more of his unique work at teknodeco.com.
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