best duct diameters to tablesaw?

[Girino]

I finally got the CV 1800 set up and closeted and now I'm working on the piping layout. Here is my idea for the tablesaw drop but I'm not quite sure how to size the ducts for the runs to the saw.

I'll have a 6" main and 6" drop from that leading to a wye for runs to the 5" opening in the cabinet below and a Shark guard with a 4" port above. I know that in general you want to keep the duct diameter large as close to the machine as you can. So, should the wye be 6 x6 x 6 with 6" runs (C and D) that reduce at the ports to 5" and 4" or do I get a 6x5x4 wye with 5" and 4" duct to the ports?

[Jim O'Dell]

If you can get the 6-5-4 wye, I'd go with that. (Must be using metal. I don't think you'll find a factory made 6-5-4 in PVC. Course, you could be building your own wyes.) Especially if the TS cabinet is set up for 5". I just cut the door my ducting goes to on my new Grizzly G0691 from the factory 4" size to 6". My main has the 6" drop that will service both saws, then continues, splits again for the band saw, and the other side to the other wall, and in that run, I have a 6-6-4 wye to service the overhead guard/pickup. If I'm not getting enough from the overhead guard, I can close off the blast gate on the cabinet a little bit. Jim.