Using a dust collector as a vacuum

[Ray Schafer]

I just bought a DC. I am going to build a chip separator, which will prevent my sucking anything metal into my impeller.

So, what I am thinking about piping to a fixed outlet at about the middle of my shop (which is very small) to use as a vacuum when I am cleaning up my shop/garage. If you agree that this is feasible, should I stick with 6 inch diameter, or should I make the last portion 4 inch for increased velocity?

[Jim Becker]

Yes, you can use a floor sweep as long as there is pre-separation to keep any metal from reaching the impeller. Stay at 6"...or at most, drop to 5". My 5" floor sweep is much more efficient than the 4" one near my lathe by a noticeable margin.

[Chip Lindley]

My Oneida system came with both fixed floor sweep duct, and a heavy duty wand for 3" hose, with little rollers to keep it from sucking to the floor. Floor sweeping could only be successful with a 2-stage DC, as mentioned, to keep metal out of the impeller.

[John Bush]

Hi Ray,
I installed two floor sweeps with gated outlets for vac hoses above the sweep gates. I have found it easier to broom sweep and dustpan as much of the sawdust and other surprises on the floor then use the vac for sucking up the fine dust and excess stuff that builds up on all horizontal surfaces. I have used the floor sweeps for the lathe shavings but it seems to take longer than with the broom and I have to empty the cyclone drum anyway. Easier to fill garbage bag in trash can and send to yard waste pick up. The vac then does a great job of cleaning up the rest of the dust. JCB

[Sonny Edmonds]

..but you are better off to use a real vacuum like a shop vac for that sort of clean up.
And here is why: You gather up dust and sand like material besides the wood debris. That junk messes up your final filter.
A shop vac is much more suited to that sort of task than your high dollar and high volume DC system.
As far as metal being picked up, I have not found that to be the case in any of my systems and modifications. While there is a huge amount of air being conveyed, a shop vac with it's ten fold static pressure ability is far more likely to actually convey a nut or such than a dust collector. And that is especially true if there is any vertical travel areas.
I have had some items like thin sliver pieces from the TS suspend in a 4" vertical in my old shop. That had 357 CFM at the port inside that saw. Measured with test equipment. But it really was a moot point because that only applied to my system at that point. I measured all my ports at the machines, but those figures were of very little value to anyone but me in my shop.
I have also had a knot wang around several times in a housing being wapped by the fan until it shot out the discharge. Now that will make your tail pipe pucker!
Use your shop vac for that sort of clean-up. And work on your DC to make that sort of clean up as little as possible.
When you get there, you will know that you are gathering as close to 100% as you can at the source.
And that is the real goal of Dust Collection anyway, let nothing get away, so nothing requires clean up. Especially sweeping.
At one point I had this drum on my shop vac system:

http://home.earthlink.net/~pie/dust_collection/old_cyclone/vacnbarrel.jpg

Now THAT is a separator. :D

[Keith Outten]

I have 20 feet of 4 inch hose with a 5 foot piece of 4 inch PVC pipe on the end that I use to vacuum my shop floor, even piles of chips from time to time. Works great, the hose can be a bit unwieldy at times though even though I have a weed eater handle on the pipe for control. I should note that I don't use a filter, cyclone or bags...my DC outlet dumps directly to a chip box located outside.
.

[Ray Schafer]

Thanks all ... once again, great advice!

[Randal Stevenson]

One more thought. While the ocassional screw may be fine to pick up, do you do any other type of work in your shop? You don't want to pick up hot metal from grinding (automotive stuff, or lawn mower blade sharpening) and have it land in kindling.

[Keith Outten]

Randal,

In my case I have two welding machines and a couple grinders I use for metal so I do hot work, wood work and use lots of plastics in my shop. Everything goes in the same chip box, even the metal chips from my milling machine. I also have a leg of my DC piping run to my laser engraver upstairs. Sparks from the laser are long extinguished before they get to the chip box.

When I am grinding or welding any chips or slag have long cooled before I start vacuuming the floor with my DC. My DC is a Grizzly 1.5 HP model that is probably 17 years old.

A couple of days ago I ordered a Dust Cobra from Oneida Air Systems. The purpose of the new Dust Cobra is to be able to vacuum my ShopBot CNC router table between projects or sheets, I need more suction than the DC is able to provide in order to be able to clean the table quickly. The new Cobra will surely be used for some other clean-up tasks as well.

I know that my setup would probably scare most people...but it works for me and has for many years. If you are more conservative with your configuration in your shop you should be plenty safe.
.