VPI 16.5 clamp

I buy the idea of a clamp covering the label, Chadnliz makes sense there. But I find it is virtually impossible to induce slippage with the stock knob snugged down. I think the amount of pressure required to make it slip would more likely stop the drive motor first....
I would never put that much pressure to cleaning to begin with. I have inadvertantly cleaned records forgetting to put the clamp on, and no slippage noted.

Wilson
Make sure the flat surface of the clamp is up this should solve the problem. When the other side is up the clamp doesn't hold some records tight.

Another possible cause of slippage, or maybe a better term could be called siezing.

The Vacuum Wand could possibly be out of vertical adjustment. There is a Collar on the vacuum wand assembly which is adjustable in height, and held in place with an allen set screw.

To adjust, remove Vacuum Wand Assembly, remove Coil Spring.
Now, with a Record on the Platter, swing the Vacuum Wand over on the Record. The collar should be adjusted that the Wand just contacts the record surface. If not, loosen Allen Set Screw on Collar, raise, or lower Collar on the Tube, and tighten Setscrew. Mark

are you saying an out-of-alignment wand would slip the record??

BTW VPI has a new Delrin wand now, lifetime guarantee, no cracking.

I bought a second hand HW-16 that appears to have been kit upgraded to a 16.5. It has the original foam platter. I've never experience a problem with slipping, but I have had a record or two seized by the vacuum wand. The LP stood still while the platter spun under it. I need to work on the wand's adjustment it appears, but I'll deal with it when my new wand arrives. The used one looks well used.