Quoted from GLSP3022:
I just did a flipper rebuild on a Dr Dude with a kit from pinball life. This is the first rebuild that has given me issues. I can't get the left flipper bat to stay tight. It wants to drift out of position with every snap of the coil. I can't possibly get the clasp bolt any tighter.
Does anyone have tricks to fix this issue? Or am I better off just getting a new clasp? Has anyone had bad clasps?
The right flipper went in perfectly.
I had the exact same problem on one of my machines.
I too, went and bought more clasps and it didn't fix the issue.
It turned out that the flipper bat was loose on it's 'spindle'!! Not so loose that it was obvious but loose enough to display the exact same problem as you are having. The glue (or whatever they use) that glues the bat to the spindle wasn't holding.
Take the flipper bat out and hold the spindle with a tool and try to turn the flipper bat by hand. I guarantee you can turn it by hand, with enough pressure.
It's not another clasp you need, it's another flipper bat.
Hope this helps.