Hate to ask this, but could use some help figuring out my DC setup

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Forum topic by g_dub posted 06-24-2017 02:10 PM 2361 views 0 times favorited 7 replies Add to Favorites Watch
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2 posts in 946 days

06-24-2017 02:10 PM

Hey folks,
First time poster, long time lurker. I was hesitant to post about this because it seems to be one topic that has been covered over and over, however I was hoping for some concise input as to my specific situation. I’ve been reading up on dust collection for months and just feel like I’m getting more and more confused. So basically I’m looking to get some input for what I actually need for my purposes vs ideal situation on paper. So here’s what I’ve got and am looking to do:
12’ x 12’ shed as my workshop (may try to blow out front wall about 4 feet depending on what kind of slope I can achieve on the roof and local codes.) Located at the back of my yard with no other structures too nearby.
I have built a 4’ x 12’ addition to the back of it to house garden tools, mower, bikes and my HF 2hp dust collector. DC will be separated from the rest of the space by some 6 mil plastic, so not too worried about the stuff that escape the bag.
Tools I’m looking to collect dust from:
Early 90’s 10” Craftsman tablesaw (built a collection port to go under it and will buy or build one for the blade guard as well. Also have it on a moveable base.)
Belt/disc sander
Drill press
Sliding compound miter saw
Bench grinder
Assorted hand tools
Pretty much all tools are on wheels/moveable due to space so will likely have to use at least some flex hose for each.
My uses for the space:
Mostly home improvement stuff, but would like to expand my “hobby”
Bicycle maintenance (obviously need to keep the dust off these)
Metalwork (yeah, I have a lot of hobbies)
Additional info:
Installing a 600 CFM exhaust fan in one of the gable vents. No issues with exhausting outside, and gable vent on the other side of the building for clean air.
Would also like to add a portable hood for use when direct connection to DC isn’t an option
Heat and A/C loss isn’t much of a concern as it’s such a small space and is pretty well insulated, so the small window A/C I have is plenty to cool it, and a small space heater warms it up quick.
Most tools are only used briefly, not a lot of sustained use.
Longest run shouldn’t be more than about 30’ including horizontal, vertical and flex (basically along 2 walls)
I have a mini Shop Vac and a decent sized one that I can use to supplement the DC if needed.
DC has a 5” inlet. 6” seems to be the recommended size, and trying to find 5” pipe and fittings is tricky. Have read about people enlarging the inlet and outlet ports, but have read mixed things about efficiency and impact on the motor. Should I try to mod the DC to accept 6” or would 4” suffice for my needs? Running 6” and reducing to 5” seems like it would really reduce airflow.
Swapping the impeller sounds like it would help a lot, but that’s getting to cost up there, at which point it might’ve been better just to buy a bigger DC (money was pretty tight when I bought it but budget is a little more flexible now. Still not trying to spend a fortune.) Is it worth it?
Not too worried about filter on the DC since it’s in a separate area.
Should I get a baffle or cyclone? This would mainly be to protect the impeller and keep the bag from clogging up and impeding the suction of the DC.
This isn’t my dream home and will likely not be here for more than another 5 years or so, so not trying to make a huge investment, but would like it to be expandable as needed.
Am I overthinking this?
Ok, I think those are the main points. Thanks for hanging in there and reading this far. Any input is appreciated!

7 replies so far

View Robert's profile


3602 posts in 2090 days

#1 posted 06-24-2017 03:07 PM

12’ x 12’ shed as my workshop

In that small of a shop I recommend no ducts just hook directly to machines with flex. Put the DC outside in closet to save space.

If you did exhaust outside, you would be pulling AC air out of the building.

-- Everything is a prototype thats why its one of a kind!!

View JBrow's profile


1368 posts in 1529 days

#2 posted 06-24-2017 03:58 PM


A small multi-purpose shop with tools on wheels and incidental woodworking suggests to me that, for now, keeping the cost low is an important consideration. I also appreciate the desire the make dust collection in a small space more effective and convenient. If woodworking becomes a serious endeavor and as the size of the workshop increases, then a fresh look at dust collection may be in order. Keeping costs down now would make it easier to spend the money for a more powerful dust collection system later.

With this in mind, 4” HVAC pipe and fittings with some blast gates to tools that stay put as well as a central drop or two for tools that roll out makes sense to me. HVAC pipe (28 gauge if conveniently found) and 4” blast gates would help keep costs down while offering respectable and convenient dust collection. Inexpensive fittings from Grizzly would offer smooth 90 and 45 degree 4” elbows that help with air flow. Sealing all the joints and seams with HVAC foil tape would help a lot by prevent leaks. If you are up for the added cost, smooth wall flex hose would likely promote air flow better than the corrugated inexpensive flex hose.

A separator added to the dust collector would do a lot to maintain air flow by keeping the filter bag cleaner longer. It could also protect the impeller. The separator could be a Thein baffle or a cyclone, either made in the shop. For a long time I used a shop made cyclone, constructed from the plans found in ShopNotes Number 13. It worked surprisingly well. There are also a few YouTube videos where various versions of the Thein baffle and cyclone separators are made.

If after upgrading your dust collection there is still too much dust in the air, looking into a commercial or shop made air cleaner might be worthwhile. With a good filter, even a box fan could improve ambient air quality. Building one from a used furnace blower and a HEPA furnace filter would be an inexpensive upgrade from the box fan.

View sawdustdad's profile


379 posts in 1494 days

#3 posted 06-25-2017 02:51 AM

I would run a 6 inch trunk line (reduced to 5 inches at the DC inlet) and drop 4 inch lines to the various tools. While the 5 inch reduction will reduce flow somewhat, it will reduce flow much less than a 5 inch trunk line. With a 2 hp DC you should have enough flow to keep dust/chips moving in the 6 inch line.

-- Murphy's Carpentry Corollary #3: Half of all boards cut to a specific length will be too short.

View BobAnderton's profile


309 posts in 3400 days

#4 posted 06-25-2017 03:21 AM

I second what SawDustDad said. The 6 inch line will have much less pressure drop per foot than 5 inch line and it does make sense to run that even if you have a 5 inch inlet to the impeller. I’d say keep it 6 inch all the way to the tool ports if possible.

-- Bob Anderton - Austin, TX - Nova 3000 lathe, Alaskan Mark III mill, Husqavarna Saw

View bigJohninvegas's profile


725 posts in 2071 days

#5 posted 06-25-2017 05:15 AM

I have that HF dust collector. Mine came with a Y fitting that took the 6” down to the 4” that most of the machines have. it also had a cap to shut off the Y if you don’t need the 2 way split.
I use it with one tube dedicated to my table saw, and the other a free hose to the rest of my tools as needed. And simple blast gates to shut off the hose not in use. I use the rockler dust right connectors on the free hose to switch from one tool to another. And I agree to put it outdoors if you can. It won’t leak enough dust to notice.
I bought that DC for $100 off craigslist almost 5 years ago. couple years back I had to replace the power switch. Most definitely I should replace the filter bag after so long. No cyclone, it just keeps on going like that energizer bunny.
My shop is a 3 car garage. I had duct work run in an early layout, but it proved to be more trouble than it was worth. I would just use a 4” flex hose to run as needed.
With 12×12 space, you will always be moving to find the best spot.
My shop is still evolving in layout design today. 5 years into this hobby, and about out of machines to buy. (can always use a new plane or lathe tools). lol
Instead of a exhaust fan, pick up a air filter. they work really well, and keeps the heat and A/C in the shop.
I use a shop vac on my miter saw, and when I am using a plunge router.
keep a disposable bag in the vac. The fines will kill the motor. I just acquired one of those blue dust right separators but have not had time to hook it up to test it.

-- John

View Ger21's profile


1089 posts in 3740 days

#6 posted 06-25-2017 12:09 PM

I also would use a length of 4” flex, with a quick connect fitting on the end. Just plug into whatever machine you are using.

-- Gerry,

View g_dub's profile


2 posts in 946 days

#7 posted 06-27-2017 06:27 AM

Thanks for all of the input. All of the research I’d done on small workshops seemed to come up with spaces close to twice that of mine, so planning this to be effective and efficient without being total overkill has been tricky. If you’ve ever worked in a space this small you know how quickly it can look like like a dust storm in there. And knowing myself and how I can be kind of lazy about things (like having to move a hose from one machine to another) the more stuff I can have hooked up at once the better (blast gates of course). I think I’m starting to get a decent plan put together based on the input here, so again, thanks for your help!

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