For the SawStop and the two router plate inserts that are going into the back bench around the SawStop, I have to put a DC duct system in, and each tool will have to be isolated from each other, so needed to make up some blast gates.
This is a further refinement of the way I've been making these blast gates in the past.
I'm doing 4" stuff (it is all actually what is called 100mm here) not the usual 6" stuff, as the 6" ducts will not make the turned needed to keep it under the back bench.
For each blast gate I start with a pile of parts.....
2 main body parts
2 end caps
2 connector pipes
OK, got that
I use my circle cutter to make the holes, you could also use a router and a template.
I put one of the pipe connectors into the hole on one body piece, and the slider's hole over the pipe too, then I use CA glue to glue the guide sticks in place. The guide sticks and the sliders are cut from the same piece of 5mm thick plywood, the body of the blast gate is 12mm thick plywood, FYI
I remove the slider and then with a sanding block, I sand the inside of the guides to make sure that no glue has oozed out.
I also take the sanding block and sand both sides of the slider, I want a tight fit, but it has to slide easily. I then glue the top body piece in place, again, using the pipe connector to keep things straight. I use CA glue, the medium stuff for wood, but I use it sparingly, and I apply it to the outside area of the guide sticks, to stop any glue oozing out into the slider area. The CA glue is not that great for holding, it is a bit brittle, but I will take care of that in a few moments!
I then insert the slider back into the blast gate body....
and line up the holes with the pipe connector. I mark the left and right of the slider.
Then I move the slider to the left, so the hole is now blocked, and the hole in the slider comes completely out of the body, this time I only mark the right side.
Then I carefully wax both sides of the slider, between the line on the left and the line on the right, this is important, because I have to glue the stops in place later, and if you slather the wax everywhere, the glue does not stick.
I used plane old car wax, but any paste wax will do.