or, how all this began…
The initial idea of this project was to have a simple device, that will “simplify” the process of switching the headphones cable from my laptop to my phone when I have a call.
Usually, like the most majority of us that are working more than 10-12 hours in the office, I use the headphones for listening to some good and uplifting music during the working process. Also, for my convenience, and from the radiation point of view 🙂 – I use the same headset to answer my phone calls, and so my dilemma began:
Unplug the 3.5 mm audio cable from the laptop, plug it in to my phone to be able to answer the call; after the call – plug it back in to the laptop to have the music back on. It was a little bit annoying. Just a little bit.
At that time, we started to investigate the existing at that moment solutions on the market, and we found out that there were some quite good 3.5mm audio switches, but most of them had a small toggle switch and were made from plastic, which didn’t perfectly fit in a modern office environment.
So our idea was to create a SMALL, SIMPLE, FUNCTIONAL and STYLISH Audio Switch Box, with an easy to push, big button. We decided to create it from wood, to bring a little piece of nature into an area already filled with too many computers and gadgets.
That is how the initial idea appeared.
Since that moment, the true calvary started, literally.
We put together the 3.5 jacks and a DPDT switch and soldered the connections. It was a rough and flimsy prototype with a dozen short thin wires intersecting each other, one that we were scared to even touch afraid not to break the connections.
We sketched the first 2D and 3D designs in Autocad, and, using Fusion 360 (another 3d cad tool from Autodesk), we were able to create in 2 days our first prototype. Thanks to our friends from Corewood (they are crafting some amazing wood sunglasses), which were glad to help us with their CNC machine, we “carved” the first switch box.
The result was a nice little wooden box sitting comfortably on the desk beside the computer, which switched the sound between the laptop and the phone when needed. It was a small, stylish, and yet a functional device.
But there was a lot to be improved there!
The wire connections just didn’t cut it – we needed a Plated Circuit Board (aka PCB). We started designing it in the “Eagle” PCB design software, which in the end gave us an idea of the minimal required dimensions of the wooden case. It also provided us a precise placement position of the components relative to each other. The goal was to make connections between the components with low electrical resistance in order to not alter the sound. We tested a lot of jacks and switches available on the market just to find the best trustworthy and durable ones which would yet be small enough to fit in the switch box.
The first PCB was “old-school” made and hand-soldered 🙂 , but it gave us a general feeling about what we had to do next.
As much as the wood is a good looking material with a pleasant finish, it is also a big pain in the ass when it comes to working it at tenths of mm scale. We had to find the right workable wood type – both good looking and durable. We tried a lot of them: pine, cherry, linden, oak, spruce. Once we even tried the cork material. In the end we fell in love with the beech – it had a nice color, a pleasant texture and the best mechanical properties for a box with such small dimensions.
Since the first prototypes, a working reliable button made from wood in a wooden box has been the biggest challenge:
- it had to be thin but strong,
- to be easy to push and yet to be able to depress itself,
- to avoid being possible to get it stuck
- to not have small clearances and yet no too small to avoid the wood deformations in time.
The first 2, 3 and 4 prototypes had a button slide stop across the whole button perimeter, yet we soon realised that it was not a viable solution – the button was flimsy and it was very easy to get it stuck. We had to come up with a form which would define a precise place of the button and which would yet allow a easy movement in the pressing direction.
We experimented with tenths of different shapes and tolerances, fought the “almighty” friction force concentrators, tested dozen of springs (even combinations) with different resilience to help us push back the button smoothly and uniformly. We even tried to make a cantilever button from the wood box itself, but we soon found out that the wood was not as elastic as we thought (yes – it was a desperate move in the search of the perfect answer).
Yet, after many trials and errors, after creating and testing more than 11 fully working prototypes, we finally came up with a design which embodied in itself the solutions of the so many engineering problems solved along the way.
Even now, we are still continuing our path of improving the product design and the manufacturing process to make the button pressing smoother and even more reliable.
BTW, if you already had a chance to try our audio 3.5 switch, please let us know (in the comments below) what do you like about this product or what you don’t like about it and how this could be improved.