scanner: back plate window opening

I needed to cut an opening into the back plate of the scanner so I could place the window that I had cut earlier. This window will allow you to see through the scanner as you scan an object in front of you. The back panel is too large to mill on the Tormach, but the window is just inside it's range of movement. I needed to elevate the panel to get it up over my tooling plate mounts, so I bolted it to a sacrificial wood panel and then clamped that to the tooling plate. I was a little nervous milling this panel as the window needed to fit exactly in the opening and I had already drilled and threaded many holes in this plate. If I messed it up, I would have to make the entire plate over again. I did a "air cutting" test over the top of the plate and confirmed that the g-code looked good, and then went for it. Everything went as planned, and the window is an excellent fit. I don't think I could have gotten the tolerances any better. I countersunk the holes in the window panel flange and moved on to the next step.