Equalization Training Tool

A simple, adjustable tool for training pressure equalization between the middle ear and the environment. If you don't know what you're doing, ask you diving instructor before use.

Original design by Nikolai Ovcharov. Check out his other cool designs at instagram.com/ovcharovnikolay!

Usage

Screw both parts together and attach a party balloon over the bottom end. Use the screw mechanism to adjust air flow resistance.

Printing

The provided Prusa Slicer project file (.3mf) already has all the right settings. Generally, I'd recommend using a default preset for a 0.2mm layer height, and setting up variable layer height for the tip of the shell. Print from PETG for best results, especially if you want to be able to wash it in hot water.

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If by any chance the screw mechanism comes out too tight or too loose on your machine, try the other exported shells with slightly different tolerances (the default one has a 0.15mm gap). You can also easily adjust this value in the provided Fusion 360 source file.

Added bottom vents and a knurled base for a more comfortable grip. Lowered the ‘lip’ for easier baloon attachment. Optimizations for easier printing.