I mentioned in the first part on design that I had guessed that the metal in metal coat hangers might be just flexible enough to form to a shape I want, and just stiff enough to provide some springy tension. It was this that formed the basis for my headband design.
Each ear piece has a ring of wood which gives it a pivot point, and out of each ring I ran a length of coat hanger wire. I used a section with a nice tight right angle in it, so that a small hook length holds the underside of the ring, whilst a straight length runs through and straight up.
Here I'm testing how much lateral pressure I can exert down the wire without it just bending permanently out of shape.
This seemed promising, so the next step was how to join these wires to a headband. The idea was simple, a small block of wood with 3 holes. the centre hole passing straight through, to take the wire up from the ear piece. The other two holes to take some bent wire that would pass over my head to another block on the other side.
I cut two lengths of straight wire from coat hangers, and shaped them by bending them around the outside of a roll of duct tape.
In the above picture you can see the wire has a plastic coating, I stripped this off of the ends where the wire goes into the holes, and I stripped it off the sections that would be bare coming up from the earpieces, but given this was going to be covered anyway, I left the plastic on.
This was probably the first point at which things started to look like credible headphones. at this point I was able to try it on my head and figure out the lengths were too long and needed adjusting.
Actually I found that the whole idea of having the headband wires come into vertical holes in alignment with the wires coming up from the earpieces was wrong. The curve of the headband doesn't need to be anything like as much as shown above, in practice the curve to reach a point just above my ears on either side of my head is a relatively shallow one.
In the above image I've made the adjustments to the length and curve of the headband wires, and I have two new wooden blocks that take the headband wires in at 45 degrees to the vertical wires. I've also turned some little covers for the ends of the vertical wires and cut them to length. So now I had some actual wearable headphones. They're a little delicate at this stage, I'd not glued any of the headband wires. But I was able to get things around my head to test the tension. Before the headband wires were glued, it was quite tricky to put them on, since the whole lot was prone to twisting.
ok, so at this point I regret not getting someone else to try them on so I don't have to show pictures of me. that's the least worst image from a lot of me looking stupid.
So now that the main structure of the headband is ok, I set to work on making it a padded band that was actually comfortable to wear. I started by glueing the wires in place.
I then cut a rectangle from one of my car sponges to fit beneath the wires. To hold everything in place I just loosely stitched some black thread through the sponge and around the wires, just enough to hold it around the curve and keep it in place.
In the above image you can just see the pulled in bits of sponge where the black thread is holding it to the wires. Also I've started to stitch some leather around it. This is more of the leather from my old leather jacket. Just two simple rectangles cut to size. I continued the theme of red stitching as an accent. In this case I learned what I'm told is a 'basic insertion stitch' that forms a fairly nice tight seam between the two pieces.
This stitching took something like 4 hours, which was fine because it was a nice sunny day and I juust sat in the garden, listened to some music, and used the stitching to keep me occupied.
The pliers you can see here make it much easier to pull the needle through the leather.
And so, at last, after about 3 weekends worth of working, I had something that looked like finished headphones!
I still had to sand the pivot pins to length, and fit some set screws to the little wooden blocks to allow me to hold the headphones vertical position relative to the headband. However they were now fully wearable, comfortable custom headphones.
At this point I made the dubious decision to also customise the jack. I had this idea that I'd turn a nice wooden version. basically make a small hole all the way through for the wire to pass through, and a large hole at one end for the jack to fit in. So I cut off the original jack, desoldered the wires, then spent about 3 hours regretting it...
It turns out the wires in headphone cables are impossibly small and delicate. They are basically a handful of very very very fine strands, wrapped around an acrylic thread core. This makes them super flexible, and almost impossible to reconnect nicely ( at least for me). I tried a lot of things, I variously got one or other headphone working, but just couldn't get a solid enough connection to both to survive being fitted securely with my little wooden jack. So I was forced to a fairly rubbish plan b. I cut the jack and a length of wire off some unused travel speakers, and just about made a good connection between the end of my headphone wire and the wire of the new end. Once the connection was good I used a hot glue gun to cover the joints, since this would support them, but also have some flexibility. I then encased this whole join in a small block of oak. I just hollowed a small recess into one block with a route in and out for the wires, put the connection point in there and glued another block on top. then sanded the whole thing to a vaguely nice looking finish.
I then did a similar thing to merely encase the existing plastic jack covering with some more oak. which I sanded to a roughly cylinder shape.
I don't have any pictures of this, I was pretty frustrated by the time I was done, having burned a few hours on the horrible decision to cut the original jack off in the first place. I very nearly didn't bother, but a voice in my head said 'why come so far with customisation and stop here?' well now I know, because it's stupidly fiddly to fix the very small wires used in headphone cables. Far, far easier to encase the existing end in some wood, which I might have taken more time and care over if I hadn't wasted so much time by then.
Despite this, I now have my very own custom headphones, resting on my custom headphone stand at work.
I've not had enough time to really make a judgement on how much better they are than the stock Microsoft headset I'm replacing. but they certainly meet the primary objective of not squashing my ears to my head when I wear them. Over the coming weeks I'm sure I'll get a chance to really run them through their paces and hopefully find they live up to their intended purpose of being comfortable for long term wear.
This all leaves me with the big question... what's next?