Steve Knight wrote:

Thanks Steve. I had come to the conclusion to use 6" snap-together metal pipe and fittings
for the overhead runs and the drop downs along the walls of my shop. Then I will have short
runs of flexible 4" tubing into or onto the dust makers.

there you go. if you can go clear to the machine with 6" it's even better but
then the 6" gates and such really start adding up in price. I need all the
airflow I can get because of the tropicals I use. they make such fine dust. s oI
had to work hard for the most airflow. soon you will find out the dc is the
cheap part (G)

--
Knight-Toolworks & Custom Planes
Custom made wooden planes at reasonable prices
See http://www.knight-toolworks.com For prices and ordering instructions.

Thanks for the additional info Steve. Pick me apart on this:

I had planned to neck down to 4" intakes at the points of dust generation. My idea for that is
that the velocity would be greater than with 6" at those points. I will be running only one
dust maker at a time. The cost of 6" blast gates is not a concern for me. Perhaps I am full of
prunes on this plan. Please advise.
Hoyt