This one can easily be made in less than an hour. For the assembly video below it took about 40 minutes, and I was taking my time to make sure and explain everything and get it right. So 30 minutes would be possible even for a first time build.
Here is a PDF of the Instructable that includes all the secondary images and annotations.
Here is a video explaining the assembly
It isn't really demonstrated much in action in that video, but it is pretty much the same as the original card in function.
Step 1: Tools and Supplies
Cardstock (the thicker the better, I use 0.012" thick and wouldn't suggest anything below that)
Stapler with staples
Small rubber band
Step 2: Print Out the Pattern
Make sure the page is not being scaled when you print it if you want business card size parts.
The pattern used for the one I built in this Instrucable had a dashed line on the upper arm. I've removed that for clarification that nothing needs to be cut there.
quick.pdf is just the normal pattern and quickfilled.pdf has all the scrap pieces filled in with a gray color to make it easy to identify which parts you don't need.
Since Instructables now requires a Pro account to download files, I've uploaded them to my site so you can still download them for free. Download here
Step 3: Cut Out Parts
The only cut that may be tricky is the slot along the bottom of the outside face. For this one you can bend the card in half longways and make two snips along the lines to get a cut started.
The template has the parts for two cards, so you only need to cut out half if you are just making one.
Step 4: Staple in the Large L Piece
It is a little difficult to line up all the parts and hold them in place for stapling. If you are having problems then some double sided tape could be used to help hold the layers together for stapling.
You can add staples anywhere that there are 5 layers. I would just add 3 or 4 at the extremities for now and add reinforcements after the card is completely assembled.
Step 5: Staple the Long Skinny Piece
It may help to move these pieces just a hair below the edge of the outside faces to make sure there is room for the legs.
Step 6: Staple the Top Arm Together
Line up the parts on the corner opposite the flap and all along the top edge.
Step 7: Add the Small Rectangles to the Flaps
You will end up with a small rectangle that is not used. This can be discarded.
Step 8: Staple the Lower Arm to the Upper Arm
Once they are in place you need to place one end of a staple as close as possible to the center of the circle marked on the face of the card. The other end of the staple needs to be off to the side of the lower arm so that it can pivot around the staple.
Make sure the arm can pivot properly before moving on to the next step.
Step 9: Staple Legs Together
Slide them into the card and make bends so that they can fold out when extended.
Step 10: Staple the Arm Assembly to the Other Assembly
The lower arm should be resting against the large L piece and the outside face of the upper arm should be aligned with the outside face of the other assembly.
Again place one edge of a staple through the hole marked on the outside face with the other edge of the staple through the skinny part of the large L piece. Make sure the arm can pivot.
Step 11: Add Rubber Band
Step 12: Add Reinforcement
You can also use pliers to press the ends of the staples flat against the card. This makes it feel better and may help a little with strength.
Step 13: Final Thoughts
Even with lots of staples this card is limited to about the same range as the glued card. However this one just starts getting floppy and hard to use with too strong of rubber bands where the glued card will break. I think if staples were added to a glued card then it would probably make a stronger card that could use stronger rubber bands and shoot farther, but I haven't tried it.
My staples were mainly just added as strength was needed. If the pattern was more planned out and consistent then it may be possible to make a more visually appealing card with this method. If anybody comes up with cool staple patterns I would love to see them.
I think this would also look pretty cool done with rivets and a more durable material like plastic or metal.