Sat Oct 05, 2024 12:49 am
1) Make a non-rotating stator to attach to the drill somewhere. The stator should have a single row of ports at a minimum - how many ports is up to you. For reference, I think Federal Signal's Model 2 is currently made with 5 ports.
2) Make a rotating rotor with the same number of ports as the stator to put into your drill's chuck. The rotor needs to fit inside the stator, and the smaller the gap between the two the better the sound output.
Be familiar with the hole size tolerances set by your slicer and output by your 3D printer. I find that I always have to add 0.5 mm at a minimum to an inside hole diameter using a 0.4mm nozzle on my FDM printer, otherwise parts won't fit together right. Also, you can check websites like Thingiverse to gather ideas for your design.
~1950 Federal Enterprises Model 5 - 12-port
1995 AM General M35A3