I just logged into YouTube and saw this really good Arkham Asylum / Arkham City / Arkham Knight locking batarang video! I’m not sure who this guy is, but he’s made a really cool batarang. It looks like the batarang is cast in fiberglass, and he’s obviously cleaned it up well and added the custom parts needed to make a really good AA batarang locking mechanism.
I actually tried this in the past with a crude sculpt, using magnets to lock it in place, but never spent any more time on it. The version in the below video is just AWESOME. Check it out: