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Forum topic by BTimmons posted 02-03-2015 08:13 PM 1053 views 2 times favorited 14 replies Add to Favorites Watch
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BTimmons

2298 posts in 1948 days


02-03-2015 08:13 PM

Topic tags/keywords: dust collector dust dust collection question

I’m needing to upgrade my dust collection in a serious way. I’ll try my best to include any info I can think of, and organize my thoughts in order to get the best advice from the experts. Here’s my situation.

Presently I work out of my garage. Been using the Harbor Freight “I can’t believe it’s not 2 HP” model of dust collector with a ghetto Thien separator, attaching a long tube of flex hose to whatever machine I’m running. It’s starting to throw off a lot of dust in weird places, and short of running beads of caulk over the entire machine and/or taking the whole thing apart and putting it back together again, I need to get rid of it. It’s done alright, better than no dust collection at all, but it’s time to move on.

Now, what follows is what I need help with.

Available square footage: I have a small (12×16) shop being built in my backyard. It has 8 foot walls and open joists. So a little more than 1500 cubic feet. My electrician buddy is wiring it with ample outlets, including 4 at 220. So power won’t really be a problem. I can expand the floor plan of the shop later if I need to, which I probably will.

Desired capabilities: I want blast gates and dedicated ducting running to each machine that I have. That includes a table saw, band saw, planer, belt/disc sander, and drill press. A floor sweep inlet would be nice, too. I have absolutely had it with dragging a hose everywhere I go. No more.

Ducting considerations: I’ve been reading up on CFM, airflow, and all that jazz. Math has never been my strong point, but I understand at least that bigger ducts mean better airflow. Ergo, better dust collection at the source. So I’m thinking 6 inch ducts, probably PVC to keep cost down. With such a small square footage to work with, I would hope that suction loss shouldn’t be too much of a problem, with the relatively short runs and all.

How much power in a DC do I need? All of this is pointless unless I have a machine that can handle it. Looking at CFM charts doesn’t help me. See the earlier point about my math skills. I don’t know if I could get by with a “true” 2 HP unit, which I know the HF isn’t. I also don’t know if something like a 3 HP cyclone would be overkill, or exactly what I need. Or maybe I’m severely underestimating things and I need to get something like a ClearVue unit.

Fine dust generators: What makes the most of the super fine dust is my table saw and my belt/disc sander. The combs that I make involves using these two machines the most. And the sander in particular sees a lot of use. I want to make sure that I’m grabbing as much of the fine stuff as I can at the source.

Health considerations: I’ve skimmed over Bill Pentz’s site. I say skimmed and not read, because I don’t have an engineering degree and two years of spare time to understand it all. There seem to be a few schools of thought regarding wood dust. The way Pentz presents things makes you think that just looking at sawdust will give you inoperable cancer. Then there are the folks who think he’s got good ideas regarding cyclone design, but he may be a bit of an alarmist where health is concerned. All I know is, my wife and five year old daughter are asthmatic as all hell, and I don’t want to be contributing to any health problems in my family, to say nothing about myself. Any DC unit I get will be augmented by an ambient air cleaner.

I’ve thought about contacting Grizzly, ClearVue, Laguna, etc., but I can’t help but think that they’re all just going to ultimately tell me that their product is the best and I won’t be able to make an objective decision here. AAAARRGH. What do I do?

Help me, Lumberjocks. You’re my only hope.

-- Brian Timmons - http://www.BigTWoodworks.com


14 replies so far

View scoobydooo9r's profile

scoobydooo9r

187 posts in 3238 days


#1 posted 02-03-2015 08:53 PM

Well, I can’t really comment from experience or knowledge dealing with the physics of DC, so I’ll just tell you what I would do. I’d just pony up the cash for a cyclone if you have the funding for it. My eyes glaze over looking at all the statistics, and frankly I don’t think that you can compare any companies numbers to another. I’m pretty certain that ClearVue makes a good product, so that’s what I was going to go with. I never bought one because I wasn’t ready to plunk down that much cash on a machine, then double that investment in ducting (I was going to go with metal).

There will be no question about suction/power if you go with a cyclone, and having that extra power will allow you to put the thing anywhere you want without worrying about duct work lengths. Plus, if you ever need to expand, you won’t need to upgrade.

I finally gave up on the idea of buying a cyclone and purchased a $450 grizzly double stack 3HP unit. I rearranged the shop so that all the big machines are in a kind of “island” with the DC in the middle. I have one main line that only goes about 8-10’, and I branched off from that. I just bought some cheapo clear flex hose that is working fine. I’ve been fairly happy with this setup, but the dang this is so loud I have to use ear protection for sure. If I had the money and the time, I’d still set up a cyclone in my shop though with automatic gates.

Sorry that I’m not really much help, but I hope that my input helps your decision. Can’t wait to see what you get, and I can’t wait to see the new shop! Congrats!

-- I don't make mistakes, I make design challenges!

View crank49's profile

crank49

3981 posts in 2434 days


#2 posted 02-03-2015 09:23 PM

Sounds like you already have a dust collector that would do what you want to do.
You say it’s leaking dust?
It will be easier to fix a few leaks than to start over for sure.
And, in the process you can greatly upgrade the HF collector for way less than a whole new machine.
The Thein separator is costing you static pressure and is not necessary; a drop out bin will work better.

You need a new toy?
After you replace the HF collectors bag with a good cartridge filter, then add an air filter for the shop.
If you don’t have one get an air conditioner, heater for the new shop.

Now, as for duct work, bigger is not always better.
Bigger is better than too small, but you can go the other way too if you are not careful.
As for the best size for the HF 2 HP collector, it will handle two pipes at the same time.
It comes with a wye inlet for the fan, with two 4” inlets. Reduce one of those to a 2 1/2” or a 3”.
Then you can collect dust through both ducts at the same time with no reduction in performance.

Table saw needs a 4” duct.
Band saw needs a 4” duct if it is bigger than a 12” band saw.
Planer needs a drop out bin exhausted by a 2 1/2” or 3” duct. I’ll explain later.
Belt/disk sander, needs a 4” duct if it’s a 6” belt and a 8” or bigger disk. A 2 1/2” duct will handle a 4” belt.
Drill press can be exhausted by a 2 1/2” duct.

Drop out bin:
We use these in industry all the time. They are simple, they work great, they are not expensive.
Application for the planer. The planer makes big fluffy chips (more like sheets) of wood.
They tend to get tangled up and pack together in the duct work, especially in elbows.
The drop out bin is simply a can, several times larger than the duct with two duct connections entering it side by side.
So, a 30 gallon metal trash can makes a nice one. Make a plywood top with two holes near the center. The holes are the size of your ducts. Run a short duct from the planer to the center hole on top of the trash can. Extend the duct down into the can about two diameters. 6” for a 3” duct. Now put a flanged duct on top of the other hole and run it to your collector inlet. The big chips will now stay in the can and only very fine dust will continue to the collector.

-- Michael: Hillary has a long list of accomplishments, though most DAs would refer to them as felonies.

View BTimmons's profile

BTimmons

2298 posts in 1948 days


#3 posted 02-03-2015 09:35 PM

Zac – Thanks for your input. Hadn’t considered a larger canister unit.

Michael – Thanks. Do you have any links or references for the drop out bins you mentioned? In my head it sounds a lot like how the separator that I’m using now works. Sort of. Also, I really hadn’t considered keeping the unit I have now. I just figured bigger is better. Although I do understand that I’ll get better suction with a Wynn filter.

-- Brian Timmons - http://www.BigTWoodworks.com

View BTimmons's profile

BTimmons

2298 posts in 1948 days


#4 posted 02-03-2015 10:10 PM

Michael – or crank49, whatever you prefer:

The way you describe the drop out bin’s construction reminds me of this, which basically resembles a Thein separator except that it doesn’t have the baffle ring underneath it.

Is that what you had in mind?

-- Brian Timmons - http://www.BigTWoodworks.com

View Roger's profile

Roger

19867 posts in 2267 days


#5 posted 02-04-2015 12:16 AM

There are many many folks on here that has spoken on this popular subject. I too have a HF 2hp collector. I added the Onieda Super Dust Deputy (got this when it was on sale for about 160) that I’m happy with. I’ve emptied my 30gal trash can 6 times now, and my bottom bag of the HF, still looks new, and has only about a tennis ball size of dust in it. That means to me, that a lot of that fine dust that was coming out of the top bag before the Super DD, is not coming out into the shop like it was. Just like you, I have hoses laying all over the floor. I’m gonna put some piping in one of these days when I have the time, and the money. Piping is gonna cost something, no matter which way you go with it. I’ve watched a lot of youtube videos that are very good. I go the way I go, because I was blessed with good looks instead of a lot o money… ok, quite laughin… Good luck with what you come up with. My only suggestion is you can get yourself a decent dust collection system without breaking your bank account.

-- Roger from KY. Work/Play/Travel Safe. Keep your dust collector fed. Kentuk55@yahoo.com

View kdc68's profile

kdc68

2526 posts in 1739 days


#6 posted 02-04-2015 12:17 AM

I have modified my HF with a 30 gallon trash can separator and a Thien Baffle. Instead of purchasing a trash can separator lid like the link you posted above, I used the actual lid that came with the 30 gallon can (modified of course). I also upgraded to a Wynn cartridge filter. While waiting for delivery of the Wynn I initially noticed some (minor) suction loss using the stock collection bag and the separator/ Thien combo. With the addition of the Wynn, the HF’s performance is like taking the separator/ Thien out of the equation. The air in the shop seems cleaner as well. A lot less dust settling on horizontal surfaces. Another plus is emptying the clear bag a fraction of what I used to…..

I’ve read numerous posts from crank49 about dust collection and IMO would be a great advisor for any technical related issues. In addition (if it may help) I have a pretty detailed project post (link below). It’s been about a year after I modified the HF and I’m still pleased. If you read through the project post and have questions, send me a PM. I’d be more than happy to try and answer.

http://lumberjocks.com/projects/99119
v
v

-- Measure "at least" twice and cut once

View crank49's profile

crank49

3981 posts in 2434 days


#7 posted 02-04-2015 02:38 AM

About the trash can dust cap, the Thein separator, and the Super Dust Deputy.

They all do about the same thing with differing degrees of efficiency of fine dust removal.

The higher the efficiency of fine dust removal, the more of your collector’s static pressure you loose.
The more pressure you loose, the less air flow you will have coming from your machines.

”But”, you may ask, “aren’t these devices supposed to improve the operation of my collector?”
The answer is no, not really. They are designed to do one of two things. Either they stop most of the big dust particles from going into the bag of your collector, or they improve the total capture of big and small dust particles.

All these devices work by spinning the air into a vortex, like a tornado in a can. The faster the air is forced to spin, the more fine particals get separated from the flow. BUT, the price for creating the very high speed circulation is static pressure. A super high efficiency cyclone could be designed that will capture even smoke particles, but the pressure required would turn a 2 hp dust collector into a 10 hp collector.

My earlier post suggesting the drop out bin is to promote the idea of LESS efficiency of separating the fine dust from the flow and just let it go into the cartridge filter where it gets captured anyway. But, the drop out bin will capture the big and heavy particles without the static robbing high velocity spinning action. So, th bulk of the big dust falls out in the bin, the lighter fine dust and air goes to the filter, and you have more air flow at the machine to capture the dust in the first place.

I didn’t invent this. It was standard practice in industrial operations when I first started work as an engineer in 1972. I’ve seen technical references dating back to the 1930’s where they have been called expansion chambers, drop out boxes, drop out bins, or just drop outs, but they all have the common goal of reducing the burden of conveying heavy dust loads through the duct work.

-- Michael: Hillary has a long list of accomplishments, though most DAs would refer to them as felonies.

View pauljuilleret's profile

pauljuilleret

71 posts in 1115 days


#8 posted 02-04-2015 12:14 PM

i did a lot of looking for ideas before I got into the dust collection business so I would try to not have to do it twice. I ran across kdc68’s article on how he made his after some thought a clone of his design is now setting in my shop and I am quite pleased with it. I would recommend you study this design with the cost of the dust collector, the winn filter along with the other items required I think the whole package cost me in the neighborhood of 650.00 to build and that was with a 40’ of 4” pvc pipe and related fittings also

View BTimmons's profile

BTimmons

2298 posts in 1948 days


#9 posted 02-04-2015 05:09 PM

Great answers from everyone so far. Thank you all. It’s been interesting that the overall feedback seems to be geared more towards improving what I have rather than investing in a new machine.

Not that I’m not in favor of saving money and doing what I can with what I’ve got, I just figured that for a dedicated ducted system, the HF would be completely inadequate for what I want to do.

-- Brian Timmons - http://www.BigTWoodworks.com

View scoobydooo9r's profile

scoobydooo9r

187 posts in 3238 days


#10 posted 02-04-2015 07:10 PM

Yeah, after thinking about it, you may as well give the HF a shot, and if it doesn’t have sufficient ooomph, drop the cash on a better one.

-- I don't make mistakes, I make design challenges!

View BTimmons's profile

BTimmons

2298 posts in 1948 days


#11 posted 02-04-2015 07:41 PM

Which seems like a great idea for the time being. Although that still leaves my worries about ducting.

I know the HF can’t handle 6 inch ducts. It just doesn’t move that much air. But say I pipe the whole shop with 4 inch, but then later determine that I really do need a bigger machine. Then I’ll be stuck with an entire system of 4 inch ducts that I’d have to just trash and replace. Several hundred bucks (and quite a bit of effort) totally down the drain.

If only the fabled pipe stretcher worked in diameter as well as length.

-- Brian Timmons - http://www.BigTWoodworks.com

View crank49's profile

crank49

3981 posts in 2434 days


#12 posted 02-04-2015 10:08 PM

I just said above that the HF will handle two ducts at once, a 4” and a 2 1/2 or 3”.
Most machines only have 4” outlets on them to start with.
If you follow my suggestion for the drop out bin the 4” will do fine.
Should you need to go to bigger equipment in the future the 6” main will handle two 4” drops at once.

-- Michael: Hillary has a long list of accomplishments, though most DAs would refer to them as felonies.

View BTimmons's profile

BTimmons

2298 posts in 1948 days


#13 posted 02-04-2015 10:37 PM

Yes, good point. Thanks for the advice.

-- Brian Timmons - http://www.BigTWoodworks.com

View KDO's profile

KDO

145 posts in 2232 days


#14 posted 02-05-2015 01:38 AM

Brian,
You might check out the newest Oneida Cyclone. It is short, designed to easily fit under a 8’ ceiling.
Also, You might check out the Penn State Industries DC line.

-- Christian, Husband, Grandpa, Salesman, amateur Woodworker.

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