Home-Made IEMs
Aug 19, 2023 at 8:59 PM Post #15,486 of 16,258
Has anyone tried to CAST a 3d resin in molds ? Like make a shell with 3d resin but without 3d printer ?
I have tried to use Siraya tech's resin inside a colloid mold but it would stick to the colloid after curing and was impossible to remove without ruining the molds (and you'd have bits of the molds glued to it).

I think I've even tried with another resin (I think it was Phrozen's resin) and it would do the same. The colloid material was Egger.
 
Last edited:
Aug 19, 2023 at 9:54 PM Post #15,487 of 16,258
Yes and no. If the UV resin is coated with a biocompatible lacquer/shellac, then theres no issue.
Yeah, depends on the lacquer. Shellac isnt exactly durable, or completely non-porous though. It would depend on whether the inner material had finished outgassing and how sweaty your ears get. It wouldnt be my choice and for a product you wouldnt have a chance, but for hobby use of test IEMs, sure, I guess. I would choose something other than shellac though personally, or just not use that resin to begin with.

'The main problem with shellac is that it's not as durable as other finishes—and it's highly flammable, thanks to the high alcohol content. This finish is susceptible to water damage and very sensitive to heat and other chemicals like ammonia or alcohol-based cleaners.'

sweat contains ammonia. Bold was already in the text I copied, so i'm not shouting, but I suppose its something appropriate to highlight :D
 
Last edited:
Aug 20, 2023 at 4:00 AM Post #15,488 of 16,258
Yeah, depends on the lacquer. Shellac isnt exactly durable, or completely non-porous though. It would depend on whether the inner material had finished outgassing and how sweaty your ears get. It wouldnt be my choice and for a product you wouldnt have a chance, but for hobby use of test IEMs, sure, I guess. I would choose something other than shellac though personally, or just not use that resin to begin with.

'The main problem with shellac is that it's not as durable as other finishes—and it's highly flammable, thanks to the high alcohol content. This finish is susceptible to water damage and very sensitive to heat and other chemicals like ammonia or alcohol-based cleaners.'

sweat contains ammonia. Bold was already in the text I copied, so i'm not shouting, but I suppose its something appropriate to highlight :D
This is not traditional “shellac” its a product from Detax. Traditional shellac uses the dried out insect excretion followed by a drying process. After the shellac flake is dried and brittle. Then it is soaked in denatured alcohol for a predetermined amount time. Once complete, the final liquid coating is then created by filtering the soaked out flake and denatured alcohol mixture through a cheesecloth. You can change performance characteristics by altering the amount shellac flake known as the pound cut. This product is NOT that. It is simply marketing terminology to distinguish detax’s line from everyone elses. Detax shellac, in any color or clear, goes on incredibly easier and cures out with a thinner/ tighter coating. This allows for a TON of room when it comes to future repairs or patches.
vapor permeability, ie how a coating breathes, is not an attribute utilized or examined in this industry to my knowledge. The major brand audiology finishes applied to either 3D print resin or pouring resin provides the same protection and appearance. Ie it locks out any off gassing from anything applied internally or from the resin. Provided a complete all encompassing coating was applied.

all that being said, I have always used biocompatible pro3dure resins for customs. For universals, I have been using an opaque black from Jayo. both types get a final shellac Coating.
 
Aug 20, 2023 at 4:03 AM Post #15,489 of 16,258
I have tried to use Siraya tech's resin inside a colloid mold but it would stick to the colloid after curing and was impossible to remove without ruining the molds (and you'd have bits of the molds glued to it).

I think I've even tried with another resin (I think it was Phrozen's resin) and it would do the same. The colloid material was Egger.
if you ever attempt this again, spritz some water in the negative and shake out the excess. Then pour and cure. I use this process when curing platinum silicone in silicone molds.
 
Aug 20, 2023 at 9:15 AM Post #15,490 of 16,258
This is not traditional “shellac” its a product from Detax. Traditional shellac uses the dried out insect excretion followed by a drying process. After the shellac flake is dried and brittle. Then it is soaked in denatured alcohol for a predetermined amount time. Once complete, the final liquid coating is then created by filtering the soaked out flake and denatured alcohol mixture through a cheesecloth. You can change performance characteristics by altering the amount shellac flake known as the pound cut. This product is NOT that. It is simply marketing terminology to distinguish detax’s line from everyone elses. Detax shellac, in any color or clear, goes on incredibly easier and cures out with a thinner/ tighter coating. This allows for a TON of room when it comes to future repairs or patches.
vapor permeability, ie how a coating breathes, is not an attribute utilized or examined in this industry to my knowledge. The major brand audiology finishes applied to either 3D print resin or pouring resin provides the same protection and appearance. Ie it locks out any off gassing from anything applied internally or from the resin. Provided a complete all encompassing coating was applied.

all that being said, I have always used biocompatible pro3dure resins for customs. For universals, I have been using an opaque black from Jayo. both types get a final shellac Coating.
thanks for the info. I wasnt aware. Thats a confusing trade name to take, given the product/material already exists.
 
Aug 21, 2023 at 3:15 PM Post #15,492 of 16,258
8 dip switches, but they simply regulate bass and treble while leaving the midrange largely untouched. Unsure how high should the treble go since I don't want to speak for trebleheads when I could be either interpreted as a basshead or as an antitreblehead (or darkhead?) but I imagine it would go from dead flat with all 4 bass switches off to +24dB at 20Hz.

I'm terrible at naming so I'd probably just call this IEM (or possibly an entire lineup of them since this could probably accomodate a large variety of driver configurations) The Equal-Loudness Contour Adjuster or ELCA for short.
This is probably the stupidest idea I've had yet but maybe and just maybe it isn't that stupid.

For all I know there's simply not enough room to cram all the necessary components.
 
Aug 22, 2023 at 8:09 PM Post #15,494 of 16,258
This is probably the stupidest idea I've had yet but maybe and just maybe it isn't that stupid.

For all I know there's simply not enough room to cram all the necessary components.

Quiet midrange (planar :) ? ) and a couple resistors/caps switched in for low and high drivers. For low driver say 2 switched resistors (giving 4 unique settings) and one cap if you can manage a low pass filter. For high driver maybe 2 caps to adjust high pass, and 1 resistor. So you can do it in 6 switches. Use smd components and solder direct to switch leads. Smaller example, those are 0805 caps I think.

Screenshot_20230822-190150_Gallery.jpgScreenshot_20230822-190117_Gallery.jpg

P.s. there are some cheap universals now with dip switches, TRN MT1 (edit: MT1 MAX) has 3 for about 15usd. Might be worth pulling the dd and grinding out the inside of the shell if you're bored.
 
Last edited:
Aug 23, 2023 at 3:42 AM Post #15,495 of 16,258
Quiet midrange (planar :) ? ) and a couple resistors/caps switched in for low and high drivers. For low driver say 2 switched resistors (giving 4 unique settings) and one cap if you can manage a low pass filter. For high driver maybe 2 caps to adjust high pass, and 1 resistor. So you can do it in 6 switches. Use smd components and solder direct to switch leads. Smaller example, those are 0805 caps I think.



P.s. there are some cheap universals now with dip switches, TRN MT1 has 3 for about 15usd. Might be worth pulling the dd and grinding out the inside of the shell if you're bored.
switches of this size are not known for having quality contacts, especially over time. I think you would be unnecessarily building in a failure mode into your IEM, when you can just do this digitally with EQ presets.
 
Last edited:

Users who are viewing this thread

Back
Top