Stick talked about a snorkle (Snork-le?) or tube through the bottom of the DC box, affixed to the bottom of the router. The easiest way to do this would be to mount two connectors flat to flat and run the flex tube up to the box and attached to one side of the connector, then a short length from the other side of the connector to the router's air intake. Pix is of the connector I'm suggesting. I would also consider putting some sort of filter box on the air intake, the less sawdust you send through the router, the better. Depending on brand, the connectors are $6-$10 each.
Making the tube fit on the bottom of the router could be done with aluminum duct tape, but you won't be able to remove it easily for other uses. For that you could get an oversized adapter with one side to fit your tubing, the other larger than the router base, then line the larger opening with door insulation strips to fit snug on the router. Easy to slip on and off and no tape residue.
Beautifully executed BTW.
The more I do, the less I accomplish.
Last edited by DesertRatTom; 03-21-2020 at 11:18 AM.