I'm floored again...and ducted...and electrified!
The ducting and electricity are done!
I now have power and dust collection to all of my machines. Let's talk about blast gates.
What exactly is a blast gate? A blast gate is a way to open and close part of a multi-branch duct system. You may have noticed in previous posts that the under-floor ducting for the dust collection system is not a straight line system. It twists and turns and branches and terminates at each machine (or potential future machine -- I built in some extra stuff for that too).
When you're operating your table saw, you don't want to be pulling dust out of your jointer. The blast gates are there to ensure just one machine at a time is receiving the full suction of the dust collection system.
Some shops have manual blast gates that you simply slide open like the one pictured above. I have this one on my floor sweeps.
Since I don't have access to the ducting (it's under the floor), I have electric blast gates. These gates work via a radio frequency system built into the gates themselves. You assign each gate a number (and set it by setting a couple of jumpers). The gate has a sensor associated with it that clamps onto the power cord of the machine it's servicing. When the sensor senses an electric current in the cord, the blast gate is opened. It simultaneously sends a signal to all the other gates in the system to make sure they're closed.
Looks like it's about time to get to work on some real woodworking stuff.