Advise needed on dust collector hose sizes

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Forum topic by rustythebailiff posted 07-27-2013 01:51 PM 4534 views 0 times favorited 5 replies Add to Favorites Watch
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93 posts in 1361 days

07-27-2013 01:51 PM

Topic tags/keywords: dust collection hose question

I have a single stage one horse dust collector that has a 4” hose coming directly off that I hook up to my table saw or planer as I need it. The hose is one of the telescoping ones from Rockler, with a max length of 12’ and a min of 3’. I would like to hook it up to some smaller tools, a router table, ROS sander, etc, using smaller diameter hoses.

My question is, is it better to use adapters at the end of the 4” hose already mounted to the collector to attach the smaller diameter hoses (2 1/2” or 1 1/2”), or remove the 4” hose and attach the smaller hose/adapters right at the machine? I’m not sure what effect going from 4 inch to 2 1/2 inch or smaller hose would have on the suction power.

-- "Necessity is the mother of invention"

5 replies so far

View Fred Hargis's profile

Fred Hargis

3842 posts in 1913 days

#1 posted 07-27-2013 03:01 PM

It’s likely to not work very well regardless of how you hook it up. DC’s are not shop vacs, they are pretty much the opposite. A DC moves a much larger volume of air at a lower static pressure (measurement of drag on the air flow). That drag increases as you choke down the flow, and the result is much less air flow. A shop vac, which is what you really need, is designed to move smaller volumes of air at much static pressures….so they pull air through the smaller hoses much better.

-- Our village hasn't lost it's idiot, he was elected to congress.

View RussellAP's profile


3059 posts in 1706 days

#2 posted 07-27-2013 03:36 PM

It’s great to have a 6” diameter when the chips fly off a planer, but matching the size of your dust ports is usually the best you can do. Anything along the path that restricts the flow makes that pipe effectively the same diameter as the restriction. So if you have 4” ports, a 6” hose is not of much benefit, some, not much.

-- A positive attitude will take you much further than positive thinking ever will.

View OhioMike's profile


73 posts in 1582 days

#3 posted 07-27-2013 04:01 PM

I tried that route with my lunchbox planer and the results were terrible.

My D.C. is 1.5 HP and I have 6 inch PVC run to the tools. But my planer had a 2.5 inch port.

So I stepped down from 6” to 4” at the blast gate and stepped down again from 4” to 2.5” at the tool. You can see in the pic how much saw dust didn’t get sucked up.

I built a new hood for the planer that has a 6” connection and now it works great.

Dust collectors just don’t do very well when the hose is smaller than 4”.

For all the tools that I couldn’t enlarge the dust port, I built this.

It works great.


View Fred Hargis's profile

Fred Hargis

3842 posts in 1913 days

#4 posted 07-27-2013 05:00 PM

Mike brings out an important point….just because the tool companies want to saddle you with an inadequate dust port doesn’t mean your stuck with it. Cut, hack, replace, whatever is necessary to get the largest your DC can use. I have one tool that I couldn’t upsize the port because of an insanely poor engineering job…all the others have modified ports.

-- Our village hasn't lost it's idiot, he was elected to congress.

View rustythebailiff's profile


93 posts in 1361 days

#5 posted 07-27-2013 08:22 PM

Ok, I understand now. I have a small port shop vac that I can hook up to the hand tools then. It will actually be a little easier to use as the hose from the DC weighs a ton.

Thanks for all the great info, I know now which direction to move

-- "Necessity is the mother of invention"

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