Araldite? I'm guessing you're not in the US, I've never heard of that one. Most plastics can be fused with the correct solvent glue and bond poorly with others. If you can confirm what the cups are made of (styrene, acrylic
, etc.)...the right glue will soften the plastic and fuse the broken parts
. If Araldite is like Crazy Glue (methacrylate) it only bonds clean breaks, it won't fuse plastics. If the break is clean, it often works well.
In any case you'd want to use as little as possible, in order to keep the cups in balance. I suspect that if you do anything to shelter it, you'll wind
up with birds landing on the shelter and somehow only causing more damage. While they are pricey, there are modern anemometers that have no moving parts, and that might be something to consider. After all, once you fix the cups, there's still a bearing under them that's going to be wearing.