it's a pretty good machine, a step up from the bench top cutters, good first step into production work, pretty accurate, it works different from the benchtop cutters, is such as you set the borders on the benchtop (BT from here on) so you are mesauring from the outside of the mount to the edge of the window, so if your blank (before you cut the window) is either slightly oversize of undersize, then this will effect the size of the window, with this machine, your datum starts n the bottom left hand corner, then you set the stops (4) from that point, so you set the left hand side stop, then add on the window size to set the right hand stop, same with the height, you set the bottom stop, then add on the height of the window to set the top stop, so doesn't matter what size blank mount you put in the machine , it will cut the same size window
You cut from the front,doing a double (or even a triple mount) you set the stops as above, (for the top mount) then you have flip down spacer stops, which when they are flipped down, make the border of the mount 5mm larger (or window 10mm smaller), stick your two blanks (for a double mount ) together, only where the mount border is, then pop in the machine, cut the top mount on the original stop settings, then when the center fall out comes out of the top mount, flip all the spacer stops down, and cut the bottom mount, you will find everything lines up running true