I wanted to say thanks for this thread. I came across this thread and remembered I had one half of a pair of ER-6is (the result of an unfortunate gardening accident!
sitting in a drawer. What I did with it is a bit different than the others in this thread have done, but it was inspired by the folks here.
So...
When I'm out and about in public, I like to listen to a single ear so I can still hear people when they talk to me, and otherwise stay aware of the environment around me. With normal IEMs this can be a bit of an issue because you have to tuck the loose IEM somewhere and you always run the risk of having it getting caught on something and ripped off and otherwise just being a pain.
I've also recently picked up a Jabra Clipper which allows me to listen to music and answer the phone for when I'm commuting. What would be optimal, is if I had a "pair" of IEMs with only one headset. Hey, I have a loose ER-6i sitting in a drawer...
I also have been
recently playing with two part silicone for DIY custom earplugs and I just broke a iPod sync cable. I broke the iPod cable down and found it had four wires, two a bit larger, stiffer and with fewer strands, but two that were pretty thin (maybe 32g?) but had more strands and were pretty supple.
OK, what the heck, let's give it a try. First, I made a ear mold with about half of a earplug kit. This is the normal amount since you are supposed to split it in half -- one for each ear. I was a bit more aggressive pushing it in however since I figured I was going to be adding more material after I fitted the ER-6i. So the mold is a bit concave. I also found something to use as a 1" bite block per advice in other threads about getting good molds for custom IEMS. OK, good so far.
Note, it is a bit harder to remove when it is pushed in so far, but we'll add more material later.
In my other thread, I mentioned using a drill to make the hole wasn't optimal and had been thinking about using a sharpened tube. I rummaged around the garage and this was the closest thing I had on-hand (don't all DIY projects start in the middle of the night?):
Yep, that works MUCH better.
Mistake 1: I didn't clean the tube first. This left the hole dirty and the stuff basically doesn't come off. Clean the tube before using.
Last time I had used a (large) drill bit to make a hole for the IEM, but that was pretty dicey and I thought I'd try something different this time. I noticed a "V" woodcarving tool and thought I'd give it a shot. Note a "U" would be a lot better, but I didn't have one handy.
That worked a lot better -- more control, but of course, be very careful if you do this, it would be very easy to cut yourself. I ended up doing a lot more work, and sometimes got distracted and forgot to take pictures. In the end, I used the "V", a flat bladed woodworking knife, and small scalpel.
I decided I'd use *two* strands of the wire per side to provide additional strength. This is intended as a commuter IEM and will probably get a bit of abuse. I twisted each wire in a drill, then twisted them together.
Then I realized my iron was a bit big. Since this was going to be in a mold, I just decided to trim the plastic away with a nipper. OK, soldered. Yes, I melted the insulation a bit. Turns out I'm pretty rusty with the old iron and I was pretty tired and impatient.
Mistake 2: Make sure you have the right tools before you start the job, go slow, etc.
I decided I'd just cover the end with epoxy so the unit would be strong and avoid straining the wires. Luckily I had some 5 minute epoxy in the garage.
Well, that worked... VERY poorly. I don't know if the epoxy was too old, or cold from being in the garage or what, but it didn't set up. Eventually after about a half hour I decided to proceed anyway. I think the epoxy idea was good, even if my execution totally failed. I had tested after soldering, but I managed to break the flex after inserting into the sleeve (you have to manhandle it a bit to push it down in there). I had already sealed it up, so I had to cut it out and solder a jumper in place of each trace on the flex.
Mistake 3: Slow down. When something doesn't work out, don't just push ahead. I should have waited overnight for the epoxy to dry, and got some new epoxy the next day to finish up.
I had intended to put a light coat of epoxy on, insert it into the mold, then add a bit more epoxy which would have fitted the mold to give it extra security. After the epoxy problem, I didn't do that, although in hindsight, my plan was good and I should have stuck to it.
It was pretty late, and I wanted to use it the next day, so I pushed on. I just sealed things up with the remaining silicon.
Mistake 4: I should have put a loop in the wire inside the mold to provide strain relief. I didn't think of this till later. Probably would be best in this case to do a loose loop, not a small knot.
OK, I soldered up the plug. I was thinking about potting the end with epoxy and using silicone as a strain relief, but the epoxy was right out, so I "potted" it with silicone and then used the silicone as a strain relief.
Mistake 5: Misjudged how much the shrink wrap would shrink. I thought I could taper the end down to the wire size with the silicone providing less and less resistance, but the tube didn't shrink down enough so I ended up just trimming it down. Since I had intended to cover it with shrink wrap, I hadn't worried about making the silicone too pretty, but now it is visible.
Mistake 6: Melted the insulation with the heat gun. Again, it comes back to being too impatient.
Mistakes aside, while it isn't the most beautiful earpiece, I'm happy with the total effect. It works well, it cost me pretty much nothing. And the ER-6i head that was gathering dust is now a usable headset. Heck, I had almost thrown it away!
[[full size pics in gallery]]
Again, thanks everyone for inspiring me to get off my rear and do this.
-john
