The following is troubleshooting information if the VH-11 hihat pad is "rotating" on the hihat stand:
First check the "stem" on the highat stand to make sure it is not spinning when you turn the clutch assembly. The stem should be tightened and not able to spin.
Next, make sure the VH-11 clutch assembly is assembled correctly. The thumb screw on the top of the pad (below the clutch) should be fairly tight on the rubber washer (grommet).
The HH cable that connects to the underside of the pad also aids in preventing any spinning. With the hihat pad in the *open* position, (foot off the pedal), take up any slack on the cable, and tie-wrap it securely to the hihat stand. You want just enough length in the cable for the pad to move up and down with no extra slack.
The following is a link to the VH-11 owner's manual on our site that you can use to confirm the correct assembly and setup of the VH-11: