In my shop, I use a centralized Belfab dust collector, with ducts to all my machinery and manually operated metal blast gates. In most cases, the gates are either right at the machine and easy to open and close. No issues. However, a few of them (for various reasons) are either in an awkward position - down low off the shop floor, behind a machine, etc. I had priced some factory made pneumatic gates, and the lowest I can find is still several hundred US. In our shop, Im always looking to make up things "quick and dirty" that are still reliable and inexpensive. Money better put towards other things.

A few of my gates I converted to pneumatic. Simple and cheaply - Chinese cylinders and controls from Amazon, some Festo style connectors and 1/4" tubing. For controlling the speed of the gate, I just turned a small brass plug that fit into the tubing, and drilled a small hole (trial and error with small # size drill bits) to slow down the action of the cylinder.

They work great, and for some machines that are used many, many times daily - between three employees - the gates are far less likely to either forgotten to be opened or closed, when the control is easily seen

https://www.youtube.com/watch?v=ryzUQJnlUVc

https://www.youtube.com/watch?v=9UwztJZahBQ