Hey Gerry, I have spent hours reading you posts. You have done some great work!! I too love to design in 3D (Solidworks) before cutting anything. I have been down the path you are you are going and would highly recommend a valve to select one or the other dust collection hose. 4" hose works great for 3hp routers. You will find a huge improvement. Otherwise I assure you will end up with piles of saw dust you still need to vacuum up by hand. One other thing I have found to be a huge improvement is the water cooled VFD motors in that they are so quiet and most importantly will not blow dust out of the collector shoe by the cooling air from a conventional router. One thing I have often thought about is having the gate valve open/close with a link to the up/down action of the router. Just some ideas Buddy! Keep up the great work! And thanks for the Screenset!
Werner