Ok yeah thats pretty bad. Don't run that, I have no idea about repairing that, probably unlikely but not my area of expertise. The other option would be to have that area cut out, and rebalanced by a motor shop. It will probably be somewhat expensive. The thing that has me wondering is the fact tha...

As I mentioned in my original post, the picture I attached is not my rotor. I included it as an example of a rotor which seems to be identical to mine. I'll try to take some pictures of the defects on my rotor. Sorry for the confusion. I took some pictures of the damaged areas on my Federal AV37X (...

A motor shop would let you know. Much safer than building your own, which would still have to be balanced anyway. Also as holler said, you should be fine... I don't even see any of the cracks you are talking about. I see some scratches. As I mentioned in my original post, the picture I attached is ...

Looks similar to a 12 port xT22 rotor too. How did they balance this one? I don't see any bolts like some of Federal's sirens are. Maybe that is what the lady bug is for... The rotor from my AV37X was balanced by drilling nineteen shallow holes about 3/4"-dia. in the bottom surface. The holes ...

Take it to a motor shop that does balancing. They will let you know what condition it is in, and if it can be salvaged or not. I assume the rotor can be rebalanced in its current condition but my concern is whether it's safe to use at all. I don't know if it's possible to safely repair cracks in th...

How would I go about locating another 18" 12-port rotor from a Model-5 which uses a gib key on a 1-1/8" motor shaft? I assume their must have been a lot of Model-5s which were retired and hopefully kept for spare parts.Thanks I would start with placing a wanted add in the wanted section, ...

The 12 port rotor is the common rotor option for model 5s, so its not super rare but isn't super easy to find either. Holler can provide you with more insight on how risky is it to run it. How would I go about locating another 18" 12-port rotor from a Model-5 which uses a gib key on a 1-1/8&qu...

Hello, I have an early version of the Federal-5 siren. It's called the model AV37X. I think it was made in 1937. It has a three phase 7.5/hp motor which is housed in a cast iron frame with a large circular base ring. It's identical to the pictures of the Federal siren which was posted here by 'Siren...

That's a big commutator. Did you resurface it? No. The motor hasn't been used. It was a new old stock spare I got with a load of stuff several years ago. I got three model 5 motors, three stators and two rotors from a power company that had them as spare parts along with a ton of other unused spare...

Yes. It is a repulsion induction motor. Thanks for the pic'. That's a big commutator. Did you resurface it? Are all large 2-phase siren motors of the repulsion design with wound rotors? I suppose a typical 2-phase induction motor with a squirrel cage rotor and starter winding would be physically tw...