Step 1: Getting Started
It was our desire to be able to have the 5W Folding USB Solar Cell from Brown Dog Gadgets setup in such a way that it would be as flat as possible, could be easily attached and removed from the briefcase, and would not require any permanent modifications to either the briefcase or the solar panel (in case either needed to be used for other applications). Although the panel is slightly bigger than this particular briefcase, you'll see that it ends up fitting nicely. And the method of attachment allows for the same panel to be attached to other briefcases of differing sizes.
Step 2: What You'll Need
There are probably as many ways to attach something are there are members on Instructables.com! For this project, we decided we would use Paracord. Using spring-loaded cord locks (such as these) will allow for adjustment and fit.
Step 3: Cut the Cord
For this project, we found that 21" was a good length for each piece of paracord. It is long enough to have length for tying knots and also long enough to have adjustment for a range of briefcase sizes.
You will need (4) lengths of paracord, each 21" long. Cut the cord to length, and use the lighter (or your desired source of fire) to melt the ends and prevent fraying. We like to mash the melted ends so that the outer jacket blends with the inner core and everything stays together.
Step 4: Tie One (or Four) On
Take each length of cord and tie a double overhand knot (or some other suitablly-sized stopper knot) on one end of the cord.
Insert each cord in one of the grommets in the Brown Dog Solar Cell and pull through until the knot stops against the panel. You will want to insert the cord from the "panel side" of the panel so that when pulled through, the stopper knots are all on the panel side of the panel. This will allow the solar panels to face outward when the finished project is attached to the briefcase.
Step 5: On the Other Ends...
On one end of the panel, take two of the loose ends of paracord and tie small bowline knots (or another type of secure loop knot) in the end of the cord. The loop should be around 1" diameter, though the exact size is not important.
On the other end of the panel, take the remaining two loose ends of paracord and insert each loose end through the cord lock.
Step 6: Make Yourself Loopy
Now we're ready to connect the ends.
Take a length of the loose end of paracord and insert it through the loop of the bowline knot. Pull it through and insert the loose end back through the cord lock. We found that using a paracord needle helped to thread the loose end through the cord lock. (the paracord needle is a sharper variation of the paracord fib described in this Instructable). Repeat for the second pair of cords.
The end result is a fixed loop (on the bowline end) and an adjustable loop (on the cord lock end).
Step 7: Put It Together!
The rest of the project is simple: Place the finished panel on the front of the briefcase and bring the loops of cord to the back. Adjust the loose loops by pulling on the loose end of paracord, while squeezing the cord lock, until the loops are tight against the briefcase.
You're ready to hit the streets and charge your gadgets! The USB port on the Brown Dog Solar Panel is nicely positioned so your charge cable can plug in and your gadget can rest right inside the front pocket of the briefcase.
The other nice thing about using paracord for this project is that it does not hamper the folding and snapping of the solar panel, allowing it to easily fold up and go inside the briefcase, should that be necessary, or for storage.