Dust collection - would you go 4" or 6" in this setup?

[Curt Harms]

That should work well. Short run, no turns. Let us know how it works once it's fully operational please.

[Alden Peterson]

That should work well. Short run, no turns. Let us know how it works once it's fully operational please.

Not pictured: the absolutely awful flex hose run to the jointer/table saw

[Chris Parks]

I'm starting to wonder if I should get an anemometer and measure my setup now, then switch it all over to proper 4" (or 6" or 5") and see how much this conversation even matters from an airflow perspective

Don't bother, they don't work due to turbulence at the duct entry and the different flow across the duct. A bell mouth entry will lessen the turbulence and increase the air flow through the duct but it does not eliminate the problems that make anemometers unsuitable for measuring duct flow.

[Bill Dufour]

I never worried about airflow since it is difficult to measure. I simply moved the neutral vane, so called, around until I got max vacuum with no duct work installed.
Max pressure differential will yield max air flow all else being the same.
Bill D

[Chris Parks]

I never worried about airflow since it is difficult to measure. I simply moved the neutral vane, so called, around until I got max vacuum with no duct work installed.
Max pressure differential will yield max air flow all else being the same.
Bill D

I haven't done this but if I wanted to optimise air flow the best thing to do would be install a manometer in the final stage of ducting nearest the dust extractor and optimise the ducting run upstream from there as it is added. You would be able to see the changes as you add to the duct run and experiment as needed. A manometer should be made for small change using a fitting into the pipe, some coloured water, a length of plastic tube and a tape measure to measure the vertical column.

manometer for dust collector - YouTube

[Curt Harms]

Not pictured: the absolutely awful flex hose run to the jointer/table saw

Some flex hose is unavoidable for most of us, all we can do is minimize it. All my machines are on wheels so no way to have rigid pipe all the way to the machine. One source says 1 foot flex = 3 feet solid as far as air flow restriction.

[Curt Harms]

I haven't done this but if I wanted to optimise air flow the best thing to do would be install a manometer in the final stage of ducting nearest the dust extractor and optimise the ducting run upstream from there as it is added. You would be able to see the changes as you add to the duct run and experiment as needed. A manometer should be made for small change using a fitting into the pipe, some coloured water, a length of plastic tube and a tape measure to measure the vertical column.

manometer for dust collector - YouTube

A simple manometer - clear tube and colored water - seems like a good inexpensive way to monitor the condition of dust collector filters. Clean filter = little air resistance. I used a loop of clear tubing so the water on both sides of the loop are about the same height. As the filter becomes clogged the height of the water columns will change. Of course then the question then becomes how much difference in the water column height is too much and the filter(s) should be serviced.