I'm planing on building a vacuum table. I've already bought Andy's book, so I'm solid on how to build the actual table but I've been looking at how to incorporate registration into it if I can. From what I've gathered, there are a couple different ways to do this. One is a floating table within a fixed frame using some method to push the table around (like with screws) to achieve registration. The other is to mount the table on top of some mechanism which can then be adjusted to get everything registered.
It's on this second method that I'm a little foggy on the specifics. I was watching this video in which he seems to be using this means of registration but I can't tell what is going on under his vacuum table. Can anyone describe how this type of registration works?