Hidden pin box lid step by step

[DLJeffs]

Some one asked how the hidden pin hinges were made for boxes. I'm certainly not the expert (Ray D showed me) but here's how I do it. This is only one way, there's probably lots of other (better ways) but the main points will be covered and you can develop your own methods that work for you.

Step 1: Save the cut offs from your lid and sides. You can use them as you create the pins and drill the holes. Saves a lot of steps taking the box apart, putting it back together, drilling holes in the wrong places so you have to remake the lid / sides, etc.

Step 2: Select your pin material. Depending on the thickness of your lid and sides, you might choose 1/8" brass. The box I'm making is smaller (roughly 10" x 4") and has a lid and sides that are 5/16" thick so I decided to just use a metal coat hanger for my pins.

Using the cutoff, you can figure out how long you want your pins. I prefer not to have the pins visible from the outside, so I keep my pins inside the sides. They can go as deep as you want into the lid (it won't show) but generally something around 1/2" - 3/4" is plenty. Cut two pins slightly shorter than the combined depth of the holes you plan to drill in both the lid and sides. It's okay if the pin can slide a little back and forth, just not all the way into one hole or the other. You can place the cutoff side you saved against the lid and lay the pin along it to test the length. If the pin is too long, nip it off. Then use a file to smooth off any sharp edges and slightly round the ends (just makes it easier to insert the pins). NOTE: If you want your pins to show on the outside of the box, you can simply drill the holes and make a pin sufficiently long to go all the way into the lid, then cut it off and sand it smooth.

Step 3: Figure out where the holes will need to be drilled. Using the cutoff from the lid, measure equal distances from the back of the lid, and from the top of the lid. I usually aim for exactly mid-point in thickness. If you decide to make your dimensions something other than equal, you will need to figure out how much room you will need to allow the lid to rotate. I use a micrometer to set the half - thickness dimension of my lid, and then use that setting to mark where the drill needs to be made on the lid. Again, measure your dimension from the both the top and from the back, you want the same dimension from both. You can cheat closer to the top/back but if you make this dimension larger than half the thickness, you'll need to leave more room for the lid to rotate upward. NOTE: If you cheat too close to the edge of the lid you risk someone opening the box too far and causing the pin to crack the lid.






I also mark the location on the cutoff I saved from the making the sides. For the holes on the sides, measure from the top and from the inside edge of the miter. Once happy, I drill a hole all the way through the test side. This is going to become a guide for drilling the holes in your lid. I use the cutoff from the lid (in which I drilled a hole) and this cutoff from the side to test the hole location. If the lid doesn't fit where I want it to, I can use the opposite edge of the side to drill another hole and re-test). When I think I have the hole in the cutoff side in the right place, I clamp the drill guide in the proper location on the lid, making the top flush and the back adjacent to the inside bevel, and drill the hole to depth.



Figure out how deep you want the holes, considering how long you want the pins and the thickness of your sides. Place a depth guide (tape) on a drill bit and drill the holes in the lid.



Drill the holes in the lid and test fit the pins using the cutoff from the side. Try to keep the holes as straight as you can (otherwise, your pins will come out at an angle and the lid will open off center). If you drill a hole to the depth you want in the cutoff from the side, you can test fit the pin length now. Make sure your miters still join properly too (see photo below).



Step 4: So now you have the holes in the lid and need to make the holes to match in the actual sides of your box. I make a drill center point (not sure what this is called) using a cutoff finishing nail. If you don't have a nail that fits snug in the hole you drilled in the lid, you can wrap a layer of tape until it fits snugly. An alternate is to cut another section of your pin material, make it long enough that about 1/16" sticks out beyond the hole. Sharpen that end of the pin to a point.







Insert your drill center into the lid (see above photos) and then placing the actual side against the lid, getting it flush with the top and adjacent to the inside of the 45 degree miter. Press the lid and side together until your drill center makes a mark you can see in the side (see photo below). This is where the hole in the side has to go. If you want to leave some clearance between the lid and the back of the box, cheat the lid away from the inside edge of the miter. If you want the lid to stick up slightly above the side of the box, cheat up a little, reverse if you want the lid to sit slightly below the top of your box. Just remember if you do this, the lid won't open past 90 degrees. Remember also that you can still sand the lid and sides, round the corners, etc. so you can adjust the fit some also when you do that.

 

[DLJeffs]

Step 5: Use your drill press to drill the holes in the sides (or you can use the cutoff with the hole in it as a drill guide). Remember to check the depth and set a stop so you don't drill too deep. Now test fit the lid and sides. You can simply tape the box sides or use a clamp set if you have one. Place the pins in the lid, bring three box sides into position, place the lid and pin into one side, then as you bring the fourth side into position, make sure the pin in the lid slides into the hole in the opposite side. You might need to shorten a pin if the miters don't mate up snugly. You might need to repeat this step more than once until you get the fit you want. NOTE: the lid will not open at this point because the back edge will contact the back side of the box so don't try to open the lid, just position it inside the box and test the fit. If the lid seems tight, look for where it is contacting the sides, and sand the lid to increase the clearance if needed or to make the clearance uniform.



Once your happy with the fit at this point, remove the lid and round off the top rear edge. This is necessary so that edge will clear the side as you open the lid (see photo below). You might need to round it some, then re-fit the lit and test it, and repeat until you get the clearance you want. This is another reason not to cheat your pin holes too close to the back or top edges of your lid.



Finally, assemble the box (without glue) one last time and check it over. The lid should open smoothly without hitting the sides (the lid will tilt down inside the box if you don't have a handle, so you might want to put a block inside to support the lid until you get the handle made). Depending on your design, it may or may not open past 90 degrees and it will not stay open on its own. Don't force it, sand and fit test until you're happy with it. NOTE: If your lid has sufficient clearance along the sides, you can put a nylon washer on your pins to prevent the lid from sliding to one side or the other (see last photo). If needed, you can simply make your own washers from the plastic on a milk carton or even an old credit card.





Finish sanding your box and glue it together, remembering to insert the lid / pins in the sides as you bring them into position and clamp or tape.

 

[Nature Man]

Thanks for the tutorial! This is very helpful! Chuck

 

[Gdurfey]

Great thread. Thanks for the details.

 

[woodtickgreg]

Thanks for doing the tutorial for others to try.

 

[Ray D]

Nicely done Doug!

 

[DLJeffs]

Nicely done Doug!

Thanks Ray. You are the inspiration to make box lids this way.

 

[Mike Hill]

That's informative!

Thank you

 

[DLJeffs]

I recently finished another box and Dan ( @djg ) asked if there was a tutorial on the hidden pins. I showed him the link to this thread. But when I reviewed it myself, I realized I was actually doing something even simpler. Here's how.

1. Save the cutoff from your lid frame. Or, cut a scrap piece of wood that matches the same dimension as your frame.

2. At the end of the cutoff / scrap piece, mark off a square with the dimensions of the height of your lid. Then drill a hole to match the size of your pin exactly through the center of this scrap / cutoff. This will now become a drill guide for drilling the holes in your actual lid and box sides.
Note: this assumes you want the lid to sit flush with the top of the box sides. If you want the lid to sit above or below the top of the sides, you'll have to adjust where you drill this hole. Remember the lid has to pivot which means the rear corner of the lid is going to need clearance away from the back side of the box. So if you off set this hole, you're also going to need to alter the amount of clearance you provide for the lid.



3. Once your lid is complete (not necessarily fully sanded), clamp this drill guide to the side of your lid frame. Clamp the guide flush with the top and rear edge of the lid frame. If your scrap is the same dimension as your lid, you now know precisely where the center point is for drilling the holes for your pins. Put a piece of tape on your drill bit to mark the desired depth, and using the hole in the guide, drill the hole for the pin. move the guide to the opposite side of the lid and drill that hole.

4. Use this same drill guide to drill the holes in your box sides. Align the drill guide flush with the top of your box. The back edge of the drill guide should be aligned with the INSIDE bevel of the box side. I like to leave about a 64th to a 32nd inch of clearance. Clamp the guide in position, set a depth for your drill bit, and using the guide, drill the pin hole in this side of the box. Switch the drill guide to the opposite side of your box, position it as shown, and drill that hole.


If you used a cutoff from the lid frame, remember to clamp outside face of the cutoff to the box side. When you drill the opposite side, do not flip the drill guide, clamp the side with the rabbet to the side of the box. If you flip the drill guide, there's a chance your holes will not be precisely even.


Note: this assumes you want the lid to sit flush with the top of your box sides. If you want the lid to sit slightly above or below the box sides, you'll need to adjust where you position the drill guide.

Note 2: if your drill guide is off center, you will need to maintain the same alignment when you drill the opposite side. For example, if the hole in your drill guide is slightly high, if you flip the drill guide when you drill the opposite side, the hole on that side will be slightly low. So remember to not flip the drill guide, just move it straight across to the opposite side, keeping the top of the guide aligned with the top of the guide. That way the holes in the box sides will be in the same position and your lid will set square.