I have six routers in lifts in my shop and the other normal woodworking machines. The routers are used for automotive interior fabrication. I work with MDF a lot. Being realistic with myself, I realized I wouldn't always line the blast gates up for optimal dust collection when switching between routers. So, I decided to automate the dust collection path lineup. My system has two branches in the main header and then a gate for each machine. So, two gates to get to the DC from the machine. I wanted the system to be transparent when in use. The brain is a small PLC (Automation Direct 06). A bit of searching around and I found a gate arrangement I liked. I bought 4" dual acting cylinders for 4" gate and 6" cylinders for the 6" gates. There is a default, deenergized flow path to the base of my Unisaw so the DC doesn't run against a dead head.
This is a video showing the operation of the gate on the bench. I'm waiting on the enclosure to arrive. The plywood is for prototyping.