I split the key so, when your tube is finished, you can remove it easily.
Also modified the end piece, so the key will fit better and doesn't "roll" out from the hole.
The frame is not easy to print, so I would modify that ( didn't have time to do that), but it came out ok. Just removing the support is not "fun" thing to do.
KEY.stl | 45.0KB | |
LOCK.stl | 151.4KB |