Briefcase

Hi! My name is Grace and I’m currently a senior studying computer science. For my final project, I made a wooden box carrier, meant to function as a purse, for all of my important belongings like my my phone, wallet, and keys.

Initial Idea

When I first decided on making a bag, I wanted to make a clear acrylic briefcase with some wood parts. I mainly just enjoyed the aesthetics of clear PVC bags, but worry about how easily the PVC may get poked/damaged/yellow. With acrylic, the bag will be studier and also fit the structured aesthetic I am looking for while also being able to take out some of the potential scratches (http://glass-polish.com/plastic-acrylic-scratches).

Another problem I wanted to tackle was that since my phone is always running out of battery, I always keep a portable charging battery and cable with me. Unfortunately, it is always making a mess and getting tangled really easily inside of my bag/backpack, which causes me lots of stress while finding my wallet and keys in my bag.

Here are some of my aesthetic inspirations in terms of what look I wanted to go for, and also how I would make the cable holder.

Challenges

So actually, my initial design was to cut clear acrylic for the main box body and have finger hinges connecting the bottom and sides of the bag together. On top of that, I wanted to have the top of the briefcase be foldable and thus introduce living hinges to the edges that would bend down and buckle into the front of the bag to keep my items secure. Quickly after digging deeper into living hinges, I found out there was going to be lots of trial and error, and also had a lower tolerance of getting stretched. Besides that, I also found that acrylic glue was not as strong as I may have hoped, and that it didn’t necessarily dry too clear. After these two main discoveries, I was pretty devastated and ended up trying to tackle a newfound problem of durability.

So now not only did I want to tackle the problem of making an aesthetic bag with an organized way of managing charger cables, but I had a newfound problem of durability.

Since I actually intended to use the bag, I wanted it to be durable and not have to constantly worry about it falling apart. This is when I took inspiration in the idea of having the bottom of the bag and the front and back be one piece of wood, and just glue many pieces stacked on top of the other. This not only solved the problem of having the bottom potentially give out, but also allowed me to create a sliding lid without needing to glue ledges to use to hold the sliding lid in place. So instead of using acrylic glue and having it potentially dry and be visible, I decided to use wood instead for both its durability, and also the aesthetic of the darker burnt laser cut edges as the outside texture of the bag.

Techniques & More Challenges

I drew a lot of technique inspiration from the laser cut laptop holder, since it also involved putting multiple panels together to form a 3d object. I also learned a lot about modeling, aligning, and getting the right parameters and measurements from this exercise. I also drew inspiration from the lamp, and using the modeling environment for the cable holder.

So the box itself is made up of 28 pieces of body panels that have a groove at the top, and a couple of special inner panels to properly inlay the acrylic. I also have two pieces with two holes for the screws for the handle, meant to be stacked on top of each other, for the lid. I figured that with a solid handle, I would be able to open and close the box more easily, in addition to having a nice black metal part to the bag.

For the cable holder, I 3d printed a small holder with a concave part used to hold the cable head. After trying it out by taping it to the side of another bag I have, I quickly realized the holder required the help of gravity to pull the cable downwards—otherwise, the cable still pops out and doesn’t really stay organized. Afterwards, I decided I wanted to make a cable winder instead, consisting of two circular ends to prevent the winded cable from falling out, and also be easily grabbed and removed. I wanted this feature because I wanted to make it so that I could attach and reattach the winder to the inner sides of my bag using magnets, or a suction cup. Unfortunately, I didn’t have enough time to print this part out, but would definitely like to think more about it and how it can best work with the bag I made.

Final Product

Going back to the box, the final design that I ended up going with had little issues, except for the need to adjust some measurements for the sliding lid groove and acrylic side pieces. One thing that did surprise me however, was how I forgot to account for the height of the screws that my handle used, and the screws ended up hitting the top of the acrylic, so my box wouldn’t open. This was easily solved by shortening the acrylic piece. The only other unpleasant surprise I had was how many pieces of the wood panels didn’t fully cut through, and I had to recut them multiple times. I tried to change the power of the laser according to the % range in the manual, but I didn’t have too much luck with that.

So all in all, I’m pretty happy with how the box turned out, and I think it’s a much much stronger design that my previous designs. The main weakness of the box is the weight and size, since it is heavy for its size. I’d say the bottom durability and lid durability are definitely the biggest strengths of the box. I don’t know how else I would build a more durable box than this one that still preserves the wood and acrylic aesthetic I was going for. 

The final bag that I made ended up going beyond my expectations when I first started the project. Even though I had to shift from a mostly acrylic aesthetic to a mostly wood aesthetic, I ended up getting the dark wood look I was originally going for without needed to acquire wood stain. For future iterations, I definitely want to test out making a larger version and attach a cross body strap to it. and also try out different colors of acrylic sides. I’d also like to try making a fully acrylic version, if I’m able to find an acrylic glue that dries completely clear, or a method of preventing the glue from showing.