[Sneeck]

Since the shaft you screwwing set screw's against is flat, it's not a big surprise it won't hold no matter how much locktite you poor on it. The only thing that will hold is welding it on.

But since that's a bad idea, i'd recommand taking a dremel and make 2 flat spot's(actually 1 is enough). Believe me when I say it won't come loose if properly done. There's nothing wrong with gripping it together.

Actually I don't know any brand that make's cvd's that hold's the cup's on like the stock slider's. All use set screw's.