If you or someone you know have ever had to travel for work, and that also meant bringing along an abundance of business cards, then you probably already know what this is all about. It’s about business cards and how they can somehow take on a life of their own, escaping what ever holds them as soon as they enter the darkness of ones luggage. It is unknown if anyone has ever witnessed how they escape their bonds but we do know that they desperately want to mingle with all the other contents locked away with them. As the light enters and the luggage is opened, it is only then that a traveler experiences that familiar frustration as they wrangle them up so they can be put on display at their trade show, job fair, or where ever they are displayed.
This strong and sturdy enclosure was created to keep those pesky cards in their place. When its time to let them out, simply push down the logo and the top will spring open, revealing a pleasant display attracting patrons to the cards contained within it.
If you haven’t done so already, you can click the image above and it will bring you to a YouTube video that shows it in action. You can also click here.
You can certainly make one of these for yourself and though I am partial to, and rather happy with, the Digi-key branding, you can alter this to fit your needs.
There was some hardware needed for this build. If you happen to need it, you may want to see the full list of products that I regularly use in my projects.
Click here to see the Hardware used in this build
| Size | Digi-Key Part Number | Supplier Part Number | Supplier | Quantity |
|---|---|---|---|---|
| 0.984" (25.00mm) | H746-ND | MPMS 003 0025 PH | B&F Fastener Supply | 2 |
| 0.315" (8.00mm) | H743-ND | MPMS 003 0008 PH | B&F Fastener Supply | 1 |
| Size | Digi-Key Part Number | Supplier Part Number | Supplier | Quantity |
|---|---|---|---|---|
| 19 mm | ATS1897-ND | ATS-PPS-10 | Advanced Thermal Solutions | 4 |
I imagine that most people already have their own versions of the tools in the image but if you are interested in one of them I have included links to the closest stocking options.
Click here to see the closest stocking products in comparison to what I used.
| Product Image | Product Description |
|---|---|
 |
Standard Pliers Long Nose Serrated 6.30" (160.0mm) |
 |
#2 Phillips Screwdriver 8.20" (208.3mm) |
 |
Handle, Torque Drive 5.91" (150.0mm) |
The drill bits and the sandpaper were my own and I am not actually sure where they were sourced.
I would like to point out that the blue driver in the image is actually a torque driver. That is not necessary. It was what I had available to me at the time. If you are need of some tools, here are some options that may be a little more appropriate for this job.
Click here to see options that will get the job done.
If you are interested in printing these items you can directly download the STL files below. If you would like to edit them to suit your own purposes you can do so by making the models your own over at 
Click here to see 3D Model downloads.
DKBCH - Box Bottom Insert.stl (3.6 KB)
DKBCH - Box Bottom.stl (703.8 KB)
DKBCH - Box Top.stl (260.1 KB)
DKBCH - Bumper.stl (17.5 KB)
DKBCH - Front Sliding Spring Holder.stl (101.4 KB)
DKBCH - Logo Base Mount Arm.stl (1.8 KB)
DKBCH - Logo Base Mount.stl (126.9 KB)
DKBCH - Logo Bezel.stl (2.0 MB)
DKBCH - Logo.stl (594.7 KB)
DKBCH - Name Plate.stl (2.2 KB)
This version of the name plate is blank. This snaps into the empty space on the back of the box bottom. If you would like a custom name please use the model at
as it can be edited to reflect the name you would like to put on it.
DKBCH - Retaining Clip.stl (5.2 KB)
DKBCH - Sliding Spring Holder.stl (86.9 KB)
DKBCH - Spring Bumper Cover.stl (4.8 KB)
You can see the logo and the logo bezel are made of multiple colors. I have a post here that explains how I was able to match the colors to our companies requirements using the filament I had available. to me.
Attaching the top
I have assembled a lot of these boxes and have learned some useful tips and tricks to make it go together easily and smoothly. I designed these parts with a tight tolerance. When I print this in PETG the parts couldn’t fit more perfectly. When I print this in PLA I find that I have to sand the joint between the box top and box bottom slightly just to make sure it does not bind. This joint needs be completely free of friction.
I have developed a system that works very well for me when I use 3mm screws in a design. I put in 2.9mm holes during the modeling process, then I use two different sized drill bits, one is slightly smaller than a 3mm screw (7/64" or 6/32"), while the other is slightly larger (1/8"). I like to clear the hinge on the bottom side (inside) with a 1/8" bit so that I know the screw can freely move. On the top side (outside)of the hinge I use the smaller bit (7/64" or 6/32") as it removes enough material that I can tap the hole while driving in the screw. If you like you can do as I did here and go half way with the 1/8" bit into the top of the box hinge. this is only to shorten the distance of which you have to thread the hole.
I like to get the screws started in the box top so that when I put it in place they are ready to be driven into the box bottom creating the hinge.
Loading the Cover Springs
You will notice that I have designed room for six springs on the back of the box bottom. Those who are building this should know that I only used one spring on each side. If you used the spring I recommend above, that should be plenty of power. . A different brand of spring may require more than one be used and I wanted to leave room for that scenerio.
If you have any issues getting the spring covers to slide into place, gently sand the entry points on the bottom box.
Installing the springs should be done in steps. You should have the spring bumper cover placed at the same level as the spring markings inside the box bottom as illustrated in the second image above. Next place the spring(s) in the channels you want them to be in. Take the sliding spring holder onto the spring(s) and compress them until the piece goes into place. Slide the spring bumper cover up until the largest flat face of that part is covered. This will prevent the assembly from popping apart before the next step can be completed.
If you look at the bumper you will see it has two registration lines that are meant to mate with the sliding spring holder. Make sure the box top is open then place the bumper so that those registration marks meet and then slide the spring bumper cover up as far as it will go.
On the inside of the spring bumper cover there are a couple of bumps that make pressing the covers all the one on difficult sometimes. These serve to keep the from falling out. I usually just give it a good knock on the table and they go in the rest of the way. Repeat the process on the other side of the box.
Prep the Logo Mount
The logo base mount gets attached to the front of the bottom box. It gets attached using two arms. They are inserted from behind the mount and then they are slid to the outside. The arms should be pushed down as tightly as possible. you may have to clean any extra artifacts out of the mounting holes. The small screw in inserted through the front and brought to flush with the rear of the mount.
Loading the Logo Springs
To mount the logo base onto the box bottom we first need to place the springs into the channel located inside the front of the box.
Once the springs are in placed we need to place the front logo spring holder on top of them. This needs to also move freely in the channel. If it is binding you may need to lightly sand the parts that rub just a little bit. The first layer will be smooth from the bed of the printer, if you do sand I recommend sanding the opposite side.
The hole in the center of the piece is where the screw from the logo mount attaches. Using the smaller bit make sure the hole is clean and if you like you can leave it there for now as it also gives us something to press down on while we place the next part.
The retaining clip here slides into the groove in the floor of the box, then the top slides forward into position and then back up to bind on the top of the channel. This keeps the part that slides and mounts to the logo mount under control.
The easiest way to get this in is to hold down on the bit, this keeps the springs compressed while we add the clip. I had a hard time getting my fingers in there to press down, I used a screwdriver on each corner.
Attaching the Logo Mount
There are two channels on the bottom box. Each arm will have to enter these channels and some bending will have to happen. I find it easier to place the second arm with a screwdriver by using it to pry the arm back.
One both arms are in, push the assembly down and it will snap into place. Gently slide the mount up as far as it will go.The part should be lined up with the one in the spring channel.
Tighten the screw, but not too much, make sure the assembly is attached snugly but easily go up an down.
The logo
As you would expect here the logo is inserted into the logo bezel. Once that is done the assembly is placed top first onto the logo mount. push down on the bottom of the logo and with both thumbs slide from the bottom around to the top.
The Insert
If you have gotten this far, congratulations! this is were we finally get to talk about the secret this business card holder beholds. The insert not only provides an angled surface to keep your cards facing the correct way when you open the box, it is always removable and leaves a space under it that is roughly a 1/4" in thickness.
I cannot say from experience but I can’t help but feel that if I were held up in a hotel and I had too much cash on me, this would be a great place to stash it. Most people have a really hard time figuring out how to open the box in general. If they do figure it out they will see a bunch of cards that are of very little interest. Those cards will cover the lines on the back wall concealing any indication of a secret compartment.
Place the insert in the box with the notched edge up. The front seats against the front of the box. The insert then lays back until you nudge each corner to assist it in snapping into the box. The notch is there so you can insert a small screwdriver to pop it out. You may have to sand the side edges a little if you find it to to be too snug of a fit. Before you sand off a lot however, remember the tight tolerance helps to hide the lines on the bottom of the box.
Attaching the Bumpons
There are four holes already designed into the bottom of the box. The bumpons referenced in the parts list fit these very nicely. Just stick em on!
I have to say that this is one my favorite projects. Many hours of design and learning went into perfecting the tolerances and the mechanical parts. I am very excited to share it and I do hope that you can use the design for your own needs.
Here is an example of one made for a Littelfuse employee. This one was made with glow in the dark material just to add a little something special. I will note that Littelfuse was not involved in the creation of the product and any copyrights are strictly theirs as usual.
As always,
Happy printing!
Keep an eye out for more of my creations as time goes on and feel free to reply here with creations of your own.
I use Onshape to create most of my designs. If you haven’t given Onshape a shot yet perhaps you should. It is very good at allowing multiple people to make their own iterations of a project and is a real asset while we are social distancing. You can start by editing this file to suit your needs as well as sharing it with a friend. Click below if you would like to learn more about OnShape in general.
The models here can be printed with with your preferred 3D printer and filaments. These as well as almost any electronic component you might need can be provided by Digi-Key.