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Forum topic by pearsondean posted 03-01-2014 05:01 AM 2575 views 0 times favorited 24 replies Add to Favorites Watch
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pearsondean

7 posts in 1019 days


03-01-2014 05:01 AM

Topic tags/keywords: dust collector dust collection

Still shopping around for dust collector. I see a kufo seco 3hp with 2750 cfm and a powermatic the same size with half the cfm and double the price. Does anyone have an idea why this might be


24 replies so far

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Gerald

51 posts in 1253 days


#1 posted 03-01-2014 05:13 AM

Probably has something to do with inflated capabilities and national brand advertising. Possibly motor and impeller quality, as well. I would check and compare the detailed specs and see if maybe anyone has evaluated them using the same test procedures and methods.

-- Gerald, Rural North Central Arkansas

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DIYaholic

19180 posts in 2142 days


#2 posted 03-01-2014 05:14 AM

Marketing….
Kufo Seco inflating the CFM….
PM inflating the price!!!

That and what Gerald said.

-- Randy-- I may not be good...but I am slow! If good things come to those who wait.... Why is procrastination a bad thing?

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pearsondean

7 posts in 1019 days


#3 posted 03-01-2014 05:48 AM

It seems you can’t really believe what you read so that leaves word of mouth. So whats some options on good quality at a fair price in the 3hp range.

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Loren

8314 posts in 3115 days


#4 posted 03-01-2014 05:53 AM

I have a 3hp Kufo 2 bag machine and it has enough suction to
do more than any one machine at a time unless you are getting
into industrial wide belt sander type things. With bag machines,
I’d look at amp draw for comparison, but I reckon all the 3hp
2 bag machines are equal more or less. Go to a 1 bag at that
impeller size and you’ll have a choked output, if such machines
even exist aside from cyclones.

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Gerald

51 posts in 1253 days


#5 posted 03-01-2014 06:14 AM

If going with a blower that is significantly larger than you expect to need is not an option, I think I would research until I found valid comparisons and pick the unit that fit your pocket book, application and whatever the best. I’m in the process of setting up a 3HP Griz in a big shop, but have the advantage of being able to just blow the chips & dust outside. Whatever you are thinking, I’d seriously recommend you do some extensive research if you want to do any more than just collect chips and sawdust.

I’m using 6” PVC S&D all the way to as close to the machine as I can go with more concern for the fine dust than the chips, although I still have visions of the system working pretty well for both. I think my weakest part of the system will be the pick-ups at the machines themselves. Most of my equipment is far from new and, in my opinion, even the new equipment falls far short of providing for adequately handling the sub-micron dust.

-- Gerald, Rural North Central Arkansas

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pearsondean

7 posts in 1019 days


#6 posted 03-01-2014 07:55 AM

The 3hp range was only because of pricing I would go larger if thats what it takes. My shop is 28×40 and would like to go over head with pipe and about 10 drops probably only 2 machines at a time. Could a 3hp handle this

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Matt Rogers

69 posts in 1437 days


#7 posted 03-01-2014 03:04 PM

According to the dust guru Bill Pentz, you can almost never properly collect the super fine (read dangerous) dust from more than one machine at a time except with a 10+ HP collector. I am sure that many here have been to his site, just search Bill Pentz and you will find about 10 hours of continuos dust collection reading.

I am moving from a 20×33 shop with a 2hp grizzly vented outside that collected dust and chips ok, to a 36×36 shop with a used Aget DustKop 7.5hp cyclone and bag house. This is the point – this dust collector only has a 2600 CFM max rating! It seems that you have to trust the lowest rating that you can find from different companies because all collectors are basically the same and if a 14” impeller and 7.5HP Baldor motor only move 2600 CFM max, then there is no way a smaller impeller and 3hp motor will pull those numbers. I even had the different ratings at different static pressures around here somewhere for my collector and it dropped down to 1000 cfm at 10” of pressure, which was easy to get even using 6” or 8” pipe.

I would say get a big dust collector and just open the windows as much as possible to exchange the air and remove the fine dust, and setup an indoor air filter to capture more of it.

-- Matt Rogers, http://www.cleanairwoodworks.com and http://www.cleanairyurts.com

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Fred Hargis

3949 posts in 1960 days


#8 posted 03-01-2014 04:00 PM

It looks to me like that Kufo Seco has 30 micron bags, which are next to useless if you’re trying to collect dust. To me, most of the single stage DC’s are all the same construction wise. So I suggest you worry a less about brand names and instead set some criteria, then sort through the models. The first criteria would be filtration, it’s best if it’s 1 micron or less. Then instead of comparing CFM’s (which are usually about as accurate as the 6.5 HP your shop vac has) compare motor amps and impeller size. If you can find a 3 HP motor with say, a 14” impeller, you’d be doing good. The 2 HP models tend to have 12” impeller, and the 1.5 HP models generally have 11” impellers. This same comparison doesn’t work with cyclone type DC’s for a number of reasons….so if you move to looking at those it would pay to come back with more questions.

-- Our village hasn't lost it's idiot, he was elected to congress.

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Gerald

51 posts in 1253 days


#9 posted 03-02-2014 02:17 AM

Matt Rogers is absolutely right about Bill Pentz and the things he’s published being a wealth of information (including a static pressure drop calculator and filtration standards tables). I’ve been trying to dig my way through the smoke and mirrors of dust collection for over two years now and have concluded that I will follow Bill’s recommendations as nearly as I possibly can. Matt, my search, however, has yielded several well documented test articles that revealed substantially different performance specs from machines with identical diameter impellers and motors drawing similar amperages. The best I can tell, different impellers and/or their housings must have different efficiencies. Anyway, I am proceeding on the theory (as yet unproven) that Grizzly’s published 2300+ CFM for my 30 micron two bag DC (dust pump) will approximate that capability when exhausted directly to open air instead of fighting “seasoned” or clogged filter bags.

Expanding some on the subject, this has been a good day for me. I finished the adaptation of a surplus 220/440 3-phase motor starter that had a 220 VAC solenoid coil to end up with a fob actuated remote control for a total cost of some misc. components I had around and just over $3 for a Radio Shack DPDT 110 VAC relay and a $6 Lowe’s special RC lamp switch – and it works like a charm from anywhere in my hanger-come-wood shop. It even looks pretty decent. :-)

Time to go contemplate the fireplace with something relaxing to sip on.

Next big steps are to get some decent weather for working in an unheated shop, to build 6” blast gates, adapt machine DC ports and/or build shrouds where necessary so that, worst offenders first, I can finally begin hooking it all up.

As satisfying as all of this is for the true “tool junkie” I am, the question dealing with will I live long enough to get all of this done in time to actually make anything has not totally illuded me.

-- Gerald, Rural North Central Arkansas

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changeoffocus

457 posts in 1084 days


#10 posted 03-02-2014 02:31 AM

Amen to all the replies, I’ve spent a lot of time view Mr. Pentz’s information that saved me money and wasted effort.
Much of that information is summarized in the replies.
“Read twice and spend once” seems like I’ve seen something like this before.
Good luck on your decision.
RMC

View Loren's profile

Loren

8314 posts in 3115 days


#11 posted 03-02-2014 02:47 AM

I think 3hp is not going to be real satisfactory for a shop that
size with overhead ducting. As with many things however,
it depends on the type of machinery you have and the volume
of work you’ll be doing.

View Gerald's profile

Gerald

51 posts in 1253 days


#12 posted 03-02-2014 03:18 AM

You may well be correct, Loren, but 3 HP is what I have and I’m going to see if I can make it do the job. If that doesn’t work, I’ll look at upgrading to more HP and a bigger impeller and go from there. If anyone is interesting, I can and will send pics.

-- Gerald, Rural North Central Arkansas

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buildingmonkey

242 posts in 1014 days


#13 posted 03-02-2014 02:00 PM

My shop is 26×50, and I have been using a 2hp Woodsucker for about 10 years. I did get a bigger filter from Wynn Environmental, seems to work fine on easy to collect machines, not so good on others. I have been adapting all machines to 6” connections, where possible, my jointer is not possible the way the dust port is built, but my small widebelt sander was built with a 5” flange, and the hole inside was only 4.5”, so I made a 5” square to 6” round adapter and cut the round flange off, and opened up the opening to match the 5” square opening inside the machine. didn’t really change anything, just sawed out the opening to fit the existing duct. Hoping it will make a difference, changed the square inches at the outlet by about 1/3. Have been considering getting a bigger impeller and motor, the housing is big enough to hold a larger impeller, and the cyclone is 20” diameter, same as the clearview. Have read you can buy a new impeller from Clearview, they use 15” on the older models, and 16” on the new ones. My old Woodsucker measures 13.25”, but it is taller than others, but have no way to test it, so can’t comment on the cfm’s. I’d be glad to move up to 3 hp, but would use Wynn’s filters unless venting outside. I don’t vent outside, because it is usually too hot or too cold, and I would like to be comfortable working.

-- Jim from Kansas

View ruel24's profile

ruel24

78 posts in 1760 days


#14 posted 03-02-2014 02:23 PM

I’d read this:

http://www.oneida-air.com/PDF/Wood%20Dust%20Collector%20review.pdf

Its a reprint from a recent Wood magazine test. To me, this answers a lot of questions. First, let me point out its not a fair comparison, as a couple of the tested devices were 2hp and the Penn State a 2.5hp model, but the Powermatic isn’t a cyclone at all, and nearly performed as well as the cyclone from Oneida, and outperformed most of the cyclones with the lowest rated filter media. It had the best suction and airflow of the group, and close to the top in the lowest particle count in the air. I wish they would have tested a 3HP Grizzly, instead of a 2HP model, but it still had problems containing the dust, saying that ”...a collector’s high air velocity can force dust particles, especially those smaller than 3 microns, through the filter if air pressure in the filter is too great.” Otherwise, their 2HP had more suction than the winning Oneida by a long shot, despite being down on HP. If they’d put a better filter on there, they might wipe the competition clean… The article does make me wonder just how accurate Pence’s claims are to reality, and even the need for a cyclone, given that a single stage dust collector does so well.

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Manitario

2402 posts in 2350 days


#15 posted 03-02-2014 08:55 PM

ruel24; a DC is a relatively simple piece of engineering, it is basically a tube with a fan at one end and a bag at the other. For good fine dust collection you want to move as much air as possible; ie. CFM. Largely this is a function of impeller size. Every DC system (the DC and all the ducting) has friction (ie. static pressure) working against it, this cuts down on the airflow and reduces CFM. Most reputable DC manufacturers will have performance curves available for their DC which will show CFM vs. static pressure. When the DC is not connected to anything, it will have the lowest static pressure, this is typically the huge numbers you see advertised, eg. the DC makes “2700 CFM”. However, start connecting duct, machines, separators etc. and you increase the friction, static pressure and the CFM drops dramatically; in essence the DC has to work harder to move the impellar against the resistance. The performance curve for each DC will show how it will perform with the static pressure of your shop setup. Eg. I use 6” duct and at the longest duct run in my shop (about 25’) the static pressure is ~11; most small DC would have crappy CFM values at this static pressure. How does a DC have better CFM at high static pressures? Usually with a larger motor coupled to a larger impeller. My current DC has a 5hp motor with a 15” impeller, I get about 900CFM at the end of my longest ducting run; with my old 1.5hp 11” impeller DC (although rated at 1900CFM) it would get about 200CFM at the end of the same run… The air sucked in by the DC has to blow out somewhere; this is through the filters or cloth bag. As the filters or bag gets clogged with fine dust, the air doesn’t blow out as easily, and the performance or CFM of the DC drops. A cyclone doesn’t initially improve performance and it certainly doesn’t make the CFM #’s higher. The beauty of a cyclone system is that it really efficiently separates the dust from the air so that very little fine dust gets onto the filters so that the performance of the DC doesn’t drop. I can go several months without cleaning the filters on my cyclone without any drop in CFM; on my old canister DC I’d have to clean the filters out several times per day or else I’d really notice the CFM drop. The ideal situation is having a large surface area for the filters so that there is very little pressure build up to “force dust particles…through the filter”. This is one of my concerns with some of the popular cyclone designs on the market is that they have very small filter surface areas.

-- Sometimes the creative process requires foul language. -- Charles Neil

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