[tomtomtom]

Hi I`m new to this forum and thread. Great find!
I've been working on IEMs for a little while now and I`m trying to acquire drivers which is difficult. So far the only easily accessible source I found is through digkey for Knowles drivers. Sonion is apparently only direct contact. 
I made great progress of making good fitting acrylic shells, which is why I`m trying to move on with the project. I didn't have time to read through the whole thread, but I think I read that some people use epoxy as IEM housing material, which may not be biocompatible. You might get rashes or worse reactions. I will post some pics of my shells if there is any interest.
 
I think I also saw someone mentioning Hackerspace. I`m in SF so maybe there can be some local collaboration!

 

[Q Mass]

  Hi I`m new to this forum and thread. Great find!
I've been working on IEMs for a little while now and I`m trying to acquire drivers which is difficult. So far the only easily accessible source I found is through digkey for Knowles drivers. Sonion is apparently only direct contact. 
I made great progress of making good fitting acrylic shells, which is why I`m trying to move on with the project. I didn't have time to read through the whole thread, but I think I read that some people use epoxy as IEM housing material, which may not be biocompatible. You might get rashes or worse reactions. I will post some pics of my shells if there is any interest.
 
I think I also saw someone mentioning Hackerspace. I`m in SF so maybe there can be some local collaboration!

 
Of course there is !! MOAR DETAILS!
 
And WELCOME... sorry for your wallet.

 

[tomtomtom]

Hi Dan,
 
Interesting that the nail polish seems to work. Both material are probably not ideal though because they are formulated as adhesive. Based on my calculation the acrylic material will make up only a marginal cost of IEMs, the majority is the BAs and connectors. In my case the cost of the acrylic should not be more than $5 per set. 
Do you have close up pictures? I'm interested in the surface morphology and transparency. Did you polish them? I will share some images of my first set that I just finished a few days ago.

 

[tomtomtom]

 

  OK. I've completed another set of CIEMs. Basically they are clear acrylic shells with Astrotec AX35 monitors in them. If you didn't know, the Astrotecs are affordable ($70) hybrid monitors with a dynamic speaker for the low spectrum and a balanced armature for the highs. Sound-wise, they are much better than my Sennheiser IE-4 and my Knowles dual driver designs. The Astrotecs are physically a bit large in the shell but I made it work. The dynamic speaker is much more suited for the lows and it really shines in the CIEM shells.
  So I did some experimenting with the different UV acrylics I've used and here's my verdict. The $5 nail salon stuff from Ebay looks, smells, flows, and cures just like the expensive Loctite stuff. That's what I'll use from now on. So total cost of the best CIEMs I have; less than $80.

Sorry Dan,
 
My previous post was supposed to be a quote!

 

[tomtomtom]

Quick follow up:
 
Here's a pic of my first finished shell. No components inside, but will follow. I used a crude setup for polishing, but just today got a fixture for my dremel that should allow cleaner preparation of the samples. What I learned from preparing the shells is that it takes a good amount of practicing and experience to understand which impression material is needed and not needed.
 
I don't have rights to upload images...see the link
 

 

[Q Mass]

That looks great!
Well done
Do you feel they're comfy/seal well?

 

[tomtomtom]

That looks great!
Well done
Do you feel they're comfy/seal well?

Thanks!
 
Coupling is great and the shell wall thickness turned out great too (not measured but ~1mm).
 
Due to a recommendation I will start testing IEMs with dynamic drivers instead of BAs. Does anyone know which model/make of dynamic drivers is popular for IEMs and possibly where to buy them?

 

[MuZo2]

Shell canal looks too short, I am wondering if it gives seal and good fit.
 

 

[MuZo2]

What acrylic did you use? was it UV cured?

 

[tomtomtom]

  Shell canal looks too short, I am wondering if it gives seal and good fit.
 

You're right the canal is a bit too short, that was a problem of the ear impression though. I ordered new dams since I hd issues with the old ones.
Material is UV curing Dreve Fotoplast.

 

[MuZo2]

Where did you buy it?
 

 

[tomtomtom]

Not sure if I can post commercial links. Google for lightning enterprises.

 

[CMOS1138]

Hello all, It has taken me more than a month to read all the way through this thread, about half way though I decided I had to make my own pare. I am still experimenting with making the shells at this point and don't have pictures to post yet. 
 
for drivers I decided to use the Knowles GK-31732-000. It is a 3 way driver combining TWFK and CI in one package pre-wired with a crossover. I have not tested my drivers out yet because I accidentally ordered to few connectors. I am eagerly awaiting delivery of all my remaining parts. 
 
I have no soldering skills to speak of and am afraid of damaging the drivers since they are a little expensive so I decided to use a conductive adhesive covered with hot glue instead of solder. I will let you all know how that works out for me
 
For shell material I have been using 2 part dental acrylic so far but I am less than happy with the results and I plan to switch over to UV cured nail acrylic for the final shell. The problem with the dental acrylic is that it hardens almost immediately once you combine the acrylic powder with the monomer liquid and so it can not be easily poured into the mold, I have compensated for this by combining the the acrylic and monomer directly in the mold a little bit at a time.
 
I plan to take pictures and post more once I have better results.
 
Thank you everyone who has contributed so many great ideas to this thread so far

 

[Dan Jarros]

Good work on the shells. How did you polish them up? I've seen the videos of the companies using a buffing wheel at high speed. I had pretty unsatisfactory results with the high speed polishing wheel on the dremel. I'd like to get a more polished finish on my future models.
DanJarros

 

[Dan Jarros]

You need to solder. Get a 20-25 watt iron with a very smooth tip and get a set of "helping hands" from EBay. Use a flux core electronics solder that melts fast and clean. I almost hate to say this but the electronics solder(specifically) from Radio Shack is really good.
DJ