On Sun, 27 Jan 2008 07:36:54 -0800 (PST), rich
wrote:

Opening one gate at a time seems to
work pretty well, but it seems that multiple open gates would just
reduce the suction at each machine. Am I missing something???


You're not missing a thing.

A given blower will only move so much air across a given pressure
differential. If you split the flow between multiple sources by
opening more than one blast gate, total flow through the blower could
be greater due to a lower pressure differential. But, except for
exceptional situations, the flow at each source will be less than if
only one gate were open.

That doesn't address the question whether or not the reduced flow at
the source is still sufficient for the purpose, but in general, for
hobbyist class cyclone/dust collector installations, it will not be.

Tom Veatch
Wichita, KS
USA