# Cyclone vs. Conventional DC



## Shop Dad (May 3, 2011)

Is there an advantage to a cyclone system like this 1.5 HP unit from Oneida at $1400 versus this 2 HP conventional DC from Grizzly at $325?

The Oneida has approx. 949 CFM @ 1.8" SP while the Grizzly has 1550 CFM, static pressure: 11"

Even adding a Wynn filter at $150 and CFM loss with Thien baffle it seems like the Grizzly is a far better deal for better suction. What am I missing?


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## woodnthings (Jan 24, 2009)

*I've wondered the same thing*

As far as I can tell, and I don't own a cylcone, I think that the cyclones get out most of the fine dust before it enters the filter(s) It seems like the CFM's are less, so there in is the dilemma. I posted this:
http://www.woodworkingtalk.com/f2/dust-collection-basics-14733/


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## WillemJM (Aug 18, 2011)

I have one of these for more than 10 years now, connected to a ducting and hose system in my shop. Works great.

http://www.grizzly.com/products/G0548ZP

The difference between the this and the Oneida.

Grizzly almost twice the capacity in CFM, there is an extra 1/2 hp and not a cyclone to add pressure drop.

Oneida filters down to 0.5-0.3 micron, the Grizzly 1 micron. I guess the question is with all the extra volume at less than half the price, which one will capture more dust leaving less floating in the shop? The Grizzly.

I won't manage with the capacity of the Oneida, so the same will cost a whole lot more.

IMHO, unless it is a high volume operation separating gallons of dust per hour, a cyclone is not practical, provided there is an easy means of keeping the filter clean. The Grizzly has a lever and a couple of turns dumps everything in the bag.


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## Dave Paine (May 30, 2012)

I do not think you are missing anything. I have also pondered getting a cyclone, but the more I looked, the more I realised I would loose CFM and static pressure no matter which manufacturer.

I am happy with my Thien baffle retrofit. It will reduce the frequency of cleaning the cannister.

If I were starting out, I would go with a system like you mentioned, a conventional DC like the 2HP Grizzly, and add the Wynn filter and Thien baffle.


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## Shop Dad (May 3, 2011)

Thanks guys. I have a 2 HP DC rated at 1200 CFM. Considering a Thien baffle reduces air flow by approx. 30% that puts it at 800 CFM making the cyclone the apparent winner but is it worth that much extra $$? Add to that any increase from a Wynn filter (200 CFM difference in the Grizzly models bag/canister) and it seems to be a wash making the standard DC the apparent winner by cost. Of course there are lots of other variables in a system but it just doesn't seem to be worth the prices going for the cyclones unless you go high end.


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## toolguy1000 (Oct 4, 2012)

Shop Dad said:


> ....... Considering a Thien baffle reduces air flow by approx. 30% .........


i assume you're referring to a thien baffle equipped separator and not an internal baffle.


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## Shop Dad (May 3, 2011)

toolguy1000 said:


> i assume you're referring to a thien baffle equipped separator and not an internal baffle.


Yes. I haven't seen approximate reduction figures for the vortex style. I like the idea if keeping chips from the impeller. I'm also not as familiar with the advantages of the vortex over a Thien-style separator but would love more info.


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## Dave Paine (May 30, 2012)

Shop Dad said:


> Yes. I haven't seen approximate reduction figures for the vortex style. I like the idea if keeping chips from the impeller. I'm also not as familiar with the advantages of the vortex over a Thien-style separator but would love more info.


I did not want to consume the pressure drop expected with a separator. I feel the impeller is designed to handle the chips. I rarely hear any impact noise, so the majority of the chips are not hitting the impeller.

In a recent thread Marv mentioned he managed to get a Jet Vortex cone and was going to do a comparison. This is good, since it needs to be the same DC.

The bottom of my DC is a plastic bag, so no airflow through this bag. Installing the Thien baffle inside the DC has eliminated the swirling of the dust/chips in the lower bag. This is energy which is no longer being consumed. I have no way to measure performance, but eliminating wasted energy feels worthwhile.

When I first installed the Thien baffle, I did notice an improvement in suction, but this was likely due to having cleaned the cannister. I am not observing the normal reduction in suction over time, or at least not a detectable reduction.


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## retired2 (Mar 14, 2013)

Shop Dad said:


> Thanks guys. I have a 2 HP DC rated at 1200 CFM. Considering a Thien baffle reduces air flow by approx. 30% that puts it at 800 CFM making the cyclone the apparent winner but is it worth that much extra $$? Add to that any increase from a Wynn filter (200 CFM difference in the Grizzly models bag/canister) and it seems to be a wash making the standard DC the apparent winner by cost. Of course there are lots of other variables in a system but it just doesn't seem to be worth the prices going for the cyclones unless you go high end.


I've seen the losses for a Thien separator quoted as 30% several times. Since there are so many different configurations of Thien separators that might be an accurate figure for some, but for my top hat build the separator caused a 38% reduction in CFM.

My testing which included anemometer readings and amp meter readings were taken with a green Delta canvas filter bag. I was curious to see how much better the system might perform with a Wynn filter, so to get data for a best case scenario, I repeated the tests with the Delta filter removed totally. There was almost no measurable difference between the geeen bag and no bag at all. 

As a result of the "no filter" test I have not rushed out to buy a Wynn filter. That does not mean I do not believe it is a worthwhile investment - quite the contrary. It should trap finer particles and it should run longer between cleanings. But a clean canvas filter bag and a clean Wynn filter will likely pass the same amount of air for a short period of time.

Like others, I am anxious to see the results of Marv's comparison's. I'm not sure if he is equiped to do it, but I would love to see measured test data comparing the Super Dust Depity to a Thein top hat separator on his Delta 50-760. Since he has his SDD close-coupled to his DC, I would suggest that he consider the addition of an air straightener. I nave no experience with the SDD, but I would guess that it imparts a spin on the exiting air much like the Thien separator.


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## rrich (Jun 24, 2009)

*With A few Caveats*

I have a Jet, 1100 CFM or there about. It has two Penn State Industries 1 micron bags. The 4 inch hose gets moved from machine to machine as needed. My shop is a ONE person shop. I don't do any "Pay the mortgage" work. My time is fun vs. time is money.

I have a trash can separator in front of the dust collector. See below

http://www.woodworkingtalk.com/f32/trash-can-separator-plastic-garbage-bag-48965/ 

The separator cost about $60 and the interior plastic trash can was going to be recycled.

This system works for me, YMMV. (Your Mileage May Vary) Only you can tell if the system would work in your shop. 

The above is pure fact and will apply to any shop.

In my shop, I empty the trash can every 3-4 weeks and the bottom DC bag about every 6 months. The bottom DC bag seems to contain only wood flour. I have not run the contents of the lower bag through a sieve, but it seems to be only wood flour.

I think that the DC cost $325 and the bags were less than $100. (It has been awhile.) Total cost about $500 then, probably $650 today. I have rewired the DC to run on 230 Volts and added a "Long Ranger" remote control. 

In the "Perfect" shop, a cyclone would be "Perfect". If I were trying to make a living on woodworking, a cyclone would be "Perfect". The thing is that I'm a retired old phart and I have a system that isn't perfect but it works very, very well in my shop. AND at the time of my DC purchase, I had about a grand to spend on other things.


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