K40 laser cutter 4 inch exhaust port

I print at 100 percent infill for maximum strength.
No supports. Many of the holes for the plastic nuts are designed to be tapped 1/4 20 so they may be slightly too small. Drill them out or tap them. The 4 inch silver vent hose I bought doesn't fit the fan so I made an adapter. It comes in two sizes. Use duct tape to tape the ducting. That's exactly what its designed for.

Assembly:
1. Install inner metal air duct using original screws and nuts. Except put the nuts on the outside o