I received a Porter Cable random orbit sander for Christmas. It's a nice tool and I like it a lot. But I can't seem to figure out how to connect it to my shop vac.

I have a RIDGID vac. If I remove the round dust filter that came with the ROS, the adapter looks like it will accept many different sizes of vac attachments. I have many different sizes of vac attachments. None of them fit! I asked the folks at Woodcraft and Rockler. They couldn't find anything that fit either.

If I pull the plastic attachment out of my vac hose, I can jam the hose onto the ROS attachment. This works, but it's a clunky solution.

Anyone know how to correctly attach a PC ROS to a shop vac?

Thanks!