In Ear Monitor Shell: Knowles ED-29689

thingiverse

Not tested This is a shell mimicing the legendary Etymotic ER4. Quick rundown of how it's supposed to be assembled: Grab 2 ED-29689's from Digikey/Mouser as well as an old earphone cable cannibalized from broken (or working) earphones. The hole in the back cap is designed for cords 1-1.5mm thick, anything over that won't fit. Test the fit by sliding the armatures into the housing -- if the armature body does not fit in the housing or the nozzle of the armature does not fit in the nozzle of the housing the model is too small, possibly due to shrinkage. Scale the model up and reprint. Thread the wires through the hole in the back caps (make sure the ends of the wire come out of the smaller-diameter side) and solder them to the two armatures according to this professional diagram. Test them to make sure they work! Tie a knot in the cord like so to prevent the soldering from coming undone when the cable is tugged. Apply a thin layer of putty/clay around the nozzle base like so. This hopefully creates a good seal without the need for acoustic tubing, although I have not tested this method yet. Alternatively, you can apply a very thin layer of epoxy (or even hot glue if you're feeling adventurous) instead of putty but it may leak into the nozzle of the armature (not good). Once again, I have not tested these hypothesized methods. Push the armature into the shell firmly. Apply epoxy or some other kind of thick adhesive to the end of the armature so it sticks to the shell. Snap on the back cap to the shell and use an adhesive to permanently attach it. Grab some acoustic dampers from Digikey/Mouser -- BF-1861-000 (green 1500 ohms) for flatter, analytical sound for extreme sound accuracy or BF-1922-000 (orange 3300 ohms) to help the weak bass become a bit more prominient by damping down those pesky mids and highs. If you can afford to, try to experiment with other dampers, as everything here is untested. Take the dampers and slide them in the front nozzle of the shell in here -- if it's too loose let me know so I can make adjustments! Put on some eartips (normal ones, not the thin ones Shure and Etymotic use) and start listening! Print Settings Resolution: 0.2 or 0.1 mm Infill: 100% Notes: ABS is highly recommended, but watch out for shrinkage.