From what are rotors and stators made?

[AllSafe]

The Elektror S2A has a brass rotor.

[Daniel]

I believe that one manufacturer of E-57's, either H?rmann or Sonnenberg, used some kind of composite fiber or plastic rotor in their newest models.

[SirenEnthusiast360]

What is the most durable thing they make componants out of now? Just find something more durable than that and you would have it made.

[Jim_Ferer]

Well, you're not going to make siren rotors out of titanium or boron fiber composites. Cost is the main reason, but the fact the siren wouldn't actually be better is the main one. Sirens last fifty years or more now, how long are you looking for? It's not the rotors that go anyhow. You might try stainless steel or bronze.

[SirenEnthusiast360]

Hypotheticly I'd want it to last 50+ years.

[Jim_Ferer]

That's my point. Sirens do last that long already, often with no real care to speak of. If you wanted to build a siren to last, you'd use lots of stainless or galvanizing, plenty of weather seals, the best permanent bearings, and rotors and stators made not to rust. Controls in a top-notch weatherproof enclosure. Good mechanical basics.

[Niklas]

I believe that one manufacturer of E-57's, either H?rmann or Sonnenberg, used some kind of composite fiber or plastic rotor in their newest models.

The production of the E57 has stopped in the early nineties, so the "new" E57s you can buy today, are restored ones. All E57s have rotors made out of hydronalium, a mixture of aluminum, magnesium, manganese and silicon.