Having "too many projects in July 2016", I receive this Leatherman's Signal from Instructables. Thank you so much. This is an awesome multi-tools and together with Cardboard Contest 2016 they are inspiring my can't- stop-thinking brain to build this Traveller's Hanger.

Step 1: Materials and Tools

Materials :

Thick cardboard. I use 3mm from Xiaomi wristband box.
4 pieces of hollow dowels from old VHS tape.
4 pieces of screws.

Tools :

Pen
Ruler
Scissors
Cutter / Hobby knife
Hole punch
Multi-purpose adhesive

Step 2: The Cuttings and Holes

Okay, these are the cuttings we need to shape from the cardboard. I have mentioned how many pieces needed. Why there it no size in it? Well, this is experimental, so you just learn from the design and shapes, size may vary but the first diagram above is drawn with vector app with appropriate ratio sizing because I was trying the swivel within the app. I wish I had a 3D printer :D

The black piece, I will called it "the cover", is made of one piece of cardboard with two bevel cuts to fold. This 3 mm cardboard is thick enough and you will not make a good folds without cutting some out of the lines. Do it slowly, do not cut it off.

The holes are harder to cut due to the thick cardboard. My hole puncher is not brand new and it has wider gap to put in the cardboard with little push :D Then I do several cuts from both sides of the cardboard. Cutter or pen knife will help if you just can't cut them off. Test fit with the hollow dowel. This dowel from the old VHS tape is just perfect with the hole punch size, and the height is also perfect with my six stack of 3 mm cardboard.

Start with the inner vertical piece. If you get "x" from left to right, then you measure "half x" from top and mark it with your pen. That is the center of your hole.

For the cover, top align the inner vertical piece to the left side and right side of the folds and align it center horizontally [see photo #6].

Then goes to the cover's bottom holes, the hanger's holes, and the hanger's bottom support holes. See the last photo for reference.

Step 3: The Curves

We need to curve some edges to get the swivel working. You don't need to curve all the edges. See above photo for reference.

Step 4: The Assembling

I make two pieces of vertical inner at each side to make it stronger to hold the shirts. Glue them together with multi-purpose adhesive. Put the dowel in the hole to get them aligned properly. Then put them on the covers' top holes.
Stick the trapezoids as above, near the bottom of the vertical inner. These shapes and positions have their purposes and will be explained later.
Stack those three hanger's bottom support at the back of the hangers, then put them on the covers' bottom holes.
Fold the covers and fit the holes together. Now you see the six stack of cardboard.

Step 5: Patches

It is already finish, but then I need some patches. Now you see that the triangle sides of the trapezoids are used to pull out the vertical inners.

Patches applied :

I put some ring washers to keep the vertical inners stay on their position.
I add small pieces of cardboard to prevent the vertical inners get too low when unfold.
I put screws inside the hollow dowels.

Step 6: Testing

I find it is a little bit too short for my shirts, so you should make it longer. My covers height are 9 cm. If we add another 2 cm on the covers, 2 cm on the vertical inners, then we get addition of 8 cm in total.

As you can see, it is strong enough to hang a sweatshirt.

And the other ends of the trapezoids can be used to hold spaghetti strap clothing ;)

Step 7: Experimental Materials

I was at first testing with cassette's cover. They are transparent, lightweight, but also fragile. It is hard to work on the swivel parts and I broke them.

I also want to make a wooden one, but also hard for me to make it happen for I only have traditional hand tools. I think I need a router for more woodworking projects.

I was about tearing down my old multi-tools, but again it is too hard to break the dowels and I thought I might end up with very bad tear-down to reuse the covers/handlers.

Although I don't think cardboard will be strong enough for this project, but the 3 mm cardboard is good in the testing phase :) I hope someone at Pier 9 will print it out and send it as a gift, who knows :D Just joking, I seldom travel anyway, and also there are a lot of commercial ones at low price in the market. Just sharing my idea ;)