"Jay Chan" wrote in message
I am under the impression that I should use as large a duct/hose as
possible while maintaining air speed to an acceptable level (3500 FPM
or something).

Right.


I will remove the two 4" inlets in the dust collector, and use the 6"
inlet directly (the 6" inlet is being covered by those two 4" inlets).
Starting with this 6" inlet, this means I should decide on whether I
should use 5" or 6" duct/hose.

Most people that us 6" run the large line as the trunk line and branch off
to each tool with a 4". Most tools have 4" ports.



I want to put a dust hook at the bottom of the table saw, and another
dust hook on top of the table saw. According to a dust collection
book, I should use a 6" dust port at the bottom of the table saw if I
want to do heavy duty cutting, such as doing dado. I will do dado, and
I will do dado on MDF. Seem like I should put a 6" port at the bottom.
And I am under the impression that I should use a 2" port to capture
dust on top of the table saw (right over the saw blade).

With a dado you, don't need the top port as there is no dust coming up. If
you want to use the 6" on the bottom, the top can be shut off for that
operation. Of normal cutting, both should be open.

That said, I don't think you need the 6" for the saw. I have the same DC
with a 4" port on my saw. I've not cut all that much dado, but is sure
handled what I cut with ease. Just how much cutting will you do at a time
and how fast can you feed the material?


I am also thinking of getting around this potential problem by using a
5" dust port at the bottom of the table saw instead of a 6" dust port.
But this will be against the recommendation stated in the dust
collection book. I am wondering whether I can use a 5" dust port for
dadoing if I can use a better dust hook, such as one that encloses the
saw blade instead of enclosing the bottom of the table saw.

Thanks in advance for any information on this issue.

Jay Chan

I think you've been reading too much. Just how big of a shop are you going
to have? In a high production automated feed and miles of panels, the book
makes a lot of sense. If you are cutting the sides of a bookcase, the 4"
port will be plenty. I've never felt the need for more capacity even
cutting some 12/4 stock. I would like to have a hose on top though.
Ed