I have a 96"x96" Avid CNC router that I cut very large square plastic parts on (82"x82" max). We have a Becker U 2.165 vacuum pump currently on the machine with just a large 2" hole in the center of the table. I am looking to upgrade the router table to have a grid pattern and use an MDF spoilboard, treating all ten of the patterns cut areas to minimize leakage.

The vacuum pump says it's 3mbar. Converting to inches of mercury using an online converter, I only get 0.09 inHg. That's like, zero vacuum. I swear the thing pulls way more vacuum than that. Am I not figuring properly? I'm thinking about adding a vacuum gauge so I can see what it's actually pulling.

I'm trying to figure out if this vacuum pump is adequate to hold down my large parts using the above mentioned strategy. Can anyone help me figure out if it's enough before I go through the process of actually just trying it?

Thanks!