High pressure vs low pressure

[brent]

Hi Guys,

I am looking at adding a dust collection system to my workshop when I move house in Jan.I want to build a cyclone dust collection system based on Bill Pentz design, I'll make the blower etc too. These systems are high volume low pressure units and are great for big tools with the wide dust extraction pipes.

So here is the question:

These big systems seem to work great for table saw, jointer and other large tools, but is it better to use a shopvac or similar for the random orbital and plunge router? Or can I use the big extractor and use a thinner hose (which lowers the flow rate)

Any advice will be welcome... Brent

[Leon]

You can use the dust collector for the small stuff also. I have a reducer at my router table fence and when adjusted for a cut that will permit suction the dust collector works very well. Placed near the bit in a drill press it catches most every thing also straight into the 4" opening.

[Paul Franklin]

I've tried it both ways on portable sanders and can't say I notice much difference. Haven't tried with a router. When I use the big collector with small tools with small hoses, I leave another port open so the collector isn't starved for air.

Paul F.

[Stephen M]

I have the big DC connected to a router table and it works fine. However, I would think that the big hose would be *way* too cumbersome to attach to a mobile tool.

I tried reducing the dust collector and attaching it to my shop vac hose once. It performed poorly.

I think if you reduce the line right at the end it works pretty well; a long narrow hose does not work so well.

FWIW the integrated dust collection (internal fan to bag) on my Makita 5" ROS actually works pretty well. It collects maybe 75%. With a suction assist, even a modest one, I suspect it would be very effective.

Steve

[J. Clarke]

If you're using the ROS in a fixed location then build a downdraft table and connect it to the dust collector with an additional hose to the ROS (that one you can just run into the main hose or pipe about four feet or so and it should get plenty of suction, no fancy fittings needed, but strap it down so the DC doesn't swallow it).

If you're moving it around go with the shop vac if it has a decent amount of power--trying to run a DC with just a 1-1/2" or so hose isn't going to work very well--it will suck fine through that hose but then the dust etc may not move through the larger plumbing due to reduced flow velocity.

[Tyke]

I have both a DC (Jet 1.5 HP Canister model) and Fein shop vac. The Fein replaced a Ridgid shop vac. I would not want to go back to the noise of the Ridgid. I do not need ear protection with the Fein.

I would not want to give up either unit. They have their designed uses and in my observation are not interchangable.

DC is great where I need high volume, low pressure. Typically due to being unable to efficiently shroud the item generating the dust. Examples are table saw, router table, radial arm saw.

I use the Fein with the Random Orbital Sander, Palm Sander which are both designed for high pressure, low volume dust removal, due to the relatively high efficiency of the collection shroud. I think trying to connect a 4in DC hose via reducers for such use will result in very small air flows and therefore inefficient dust removal.

I also use the Fein for general shop dust cleanup. The smaller hose is easier to move around.

Dave Paine.

[Leon]

My dust collection is different from most. I use 20' of flex hose and attach it to what ever tool I am using.

I use a 20" fan at may back for dust extraction when I sand. ;~)