Dust Collector as Dust Extractor?

[TheTechRunner]

I'm starting to put together my basement workshop and dust collection is obviously a big thing on my mind (happy wife happy life anyone?). I currently have a 1200 CFM 2x4"/1x6" dust collector that I plan on putting in the garage and piping a 4" (or 6") line through the rim joist into the basement after it goes through a cyclone attached to a 50 gallon drum. My understanding from doing some reading online is that a dust extractor is much better with smaller tools (i.e. sander, track saw) where a collector is better with larger tools (i.e. planer, table saw).

Given that background...
Can I put a second cyclone in the basement to go down to a smaller hose? I'm trying to avoid buying a dust extractor as well since I've already made an investment into a dust collector.

So for my small tools I would have... tool -> cyclone -> bin -> 4" -> cyclone -> bin -> dust collector. For larger tools I would bypass the first cyclone/bin.

 

[bnaboatbuilder]

Do more research so you'll understand the air speed / air volume differences between a large dust collector and a "shop vac" which is what the Festool vacs are, just shop vacs.

A shop vac is much better for small power tools. Dust collector for large stationary tools.

 

[TheTechRunner]

I have seen a lot of people talk about that but I haven't been able to get any real numbers/evidence. I know that throwing a 4" hose on a 27mm tool isn't going to work too swell, but if I have a 4" hose to a bin to a cyclone to a 27mm hose, wouldn't that work?

Cutting down the diameter should increase velocity. Look at what happens with a water hose. If you put your finger over the end and decrease the opening, the water comes out much faster and goes further than if you leave your finger off the hose.

Side note: I'm no physics expert. Just a guy looking for evidence and trying to justify not spending money on something that I don't need to if I don't have to.

 

[Oldwood]

Just in case you have not considered it, removing 1200 cfm from the basement without returning the air will downdraft any gas appliances you may have.  [eek]

 

[TheTechRunner]

Just in case you have not considered it, removing 1200 cfm from the basement without returning the air will downdraft any gas appliances you may have.  [eek]

Thanks Fortunately I have heard that so it's in my plans to put in a return as well.

 

[AlexThePalex]

but if I have a 4" hose to a bin to a cyclone to a 27mm hose, wouldn't that work?

Nope, that doesn't work. You just don't get the suction necessary for a small power tool that way.

I also could imagine that reducing the diameter of your cyclone's dust channel too much might overburden your cyclone and possibly damage it.

 

[bnaboatbuilder]

You're welcome to experiment with your dust collection system, or you can do what a million other woodworkers do. The methods have already been designed so not sure why those methods aren't reason enough. No fake news in dust collection. Pipe 4" or 6" to large machines from a dust collector and then use a shop vac for handheld power tools and other shop power tools such as a miter saw.

A cyclone serves the purpose of separation of large debris from smaller debris/dust so collection is handled in such a way that fewer vac bags are wasted or large plastic bags on a dust collector are used by putting larger debris in another simple to empty canister.

 

[TheTechRunner]

So what I'm hearing is I should buy the refurb CT 26 that's on sale right now...

Sounds like it all comes down to static pressure. Small hoses have large static pressures which DCs stink at (12" vs 96"). The only reason I can think for that is that shop vacs have much higher RPM than DCs (15k+ vs 3.5k).

 

[Sparktrician]

Just in case you have not considered it, removing 1200 cfm from the basement without returning the air will downdraft any gas appliances you may have.  [eek]

Thanks Fortunately I have heard that so it's in my plans to put in a return as well.

 

Be sure that it's an outside fresh air return and not from the garage...  [scared] 

 

[TheTechRunner]

Just in case you have not considered it, removing 1200 cfm from the basement without returning the air will downdraft any gas appliances you may have.  [eek]

Thanks Fortunately I have heard that so it's in my plans to put in a return as well.

 

Be sure that it's an outside fresh air return and not from the garage...  [scared]

Are you implying that breathing carbon monoxide wouldn't be good?  [big grin] Not that my garage actually gets used for vehicles  [sad]

 

[amt]

So what I'm hearing is I should buy the refurb CT 26 that's on sale right now...

Sounds like it all comes down to static pressure. Small hoses have large static pressures which DCs stink at (12" vs 96"). The only reason I can think for that is that shop vacs have much higher RPM than DCs (15k+ vs 3.5k).

There are some dust collectors like Oneida's smart DC which can vary the impeller speed to increase static pressure, but even then I am not sure if it is enough to have same CFM for 27mm hose as a standard dust extractor (shop vac). 

I recently bought a vacuum motor/blower capable of 240 CFM, almost double that is a festool vac.  I am basically creating my own stationary dust extractor with cyclone and 2" PVC for piping.  At one point it occurred to me that 4 of these combined could probably replace my 5HP dust collector and serve both purposes...

 

[TheTechRunner]

There are some dust collectors like Oneida's smart DC which can vary the impeller speed to increase static pressure, but even then I am not sure if it is enough to have same CFM for 27mm hose as a standard dust extractor (shop vac). 

I recently bought a vacuum motor/blower capable of 240 CFM, almost double that is a festool vac.  I am basically creating my own stationary dust extractor with cyclone and 2" PVC for piping.  At one point it occurred to me that 4 of these combined could probably replace my 5HP dust collector and serve both purposes...

That's intriguing to me. What did you buy?

 

[Klemm]

[member=67630]TheTechRunner[/member]  - I'm with [member=23087]bnaboatbuilder[/member] in his Post # 6 above - based on my experience with every kind of collection system (and some dust "redistribution" systems  [sad]).''There's much more to effective dust collection than meets the eye so do what has proven to work, don't try to reinvent the wheel and devote your time to WOODWORKING instead - enjoy [smile]

Hans

 

[JayStPeter]

I have been able to reasonably make some benchtop tools work well with my big Oneida cyclone: Miter Saw, OSS, and a few others.  The trick is usually to run some larger diameter tubing right to the tool and neck it down at the connection point.  In fact, it works better on my Miter saw than a vac.  But, it doesn't work nearly as well on the Festool router/track saw/sanders as a shop vac'ish device.  You can get passable results by running 3" tubing right up to the tool, but it's not real convenient to run a router or sander with a 3" hose running up to it with a bunch of adapters with hose clamps holding it all together.  I do have the little dust deputy on my Fein to make it easier to deal with day-to-day.  The older commercial Oneida I have is also a beast.  The old Jet bag unit I had couldn't do what that thing does.

 

[amt]

That's intriguing to me. What did you buy?

Lamb Ametek 119892-0

It is a beast of a blower.  I have not incorporated it with a filter and cyclone yet, but when I tried to measure it, it maxed out the anemometer.  Kleen-rite has the lowest price I could find, at around $129.  Hopefully soon I'll have it plumbed with a hepa filter and a clear vue mini cyclone.  I suspect even with the cyclone, it will be far more powerful than the ct-mini I have.

 

[Jim Metzger]

On the safety front the garage should have a continuous (1) hour rated separation from the interior of the house including a basement. Any penetrations between the garage and house should have a rated duct and rated fire resistive foam sealant. It isn't a big thing until it is.

Jim