Dust collector question

[Donnie Harkins]

Hi guys,


I'm going to take a look at a 2HP grizzly dust collector this week. i will probably pick it up, but i had a question for the community first.

Will adding a cyclone like a dust deputy ahead of the machine add any benefit? i thought i had read somewhere that this could increase the performance of DC's, but now i cant seem to find where i read that.

[Al Launier]

A number of references here by searching "dust deputy" https://www.google.com/search?sitesearch=www.sawmillcreek.org&q=dust+deputy&submit.x=9&submit.y=6&gws_rd=ssl. This help.

[glenn bradley]

Hi guys,


I'm going to take a look at a 2HP grizzly dust collector this week. i will probably pick it up, but i had a question for the community first.

Will adding a cyclone like a dust deputy ahead of the machine add any benefit? i thought i had read somewhere that this could increase the performance of DC's, but now i cant seem to find where i read that.

Depends on which performance characteristic you are talking about. Blowers designed for cyclones expect the flow resistance added when one is present; non-cyclone units do not. Adding anything in the path of a dust collector (including ducting :)) impacts the system. Unfortunately it cuts both ways:
- If you are after better separation and can tolerate the reduced airflow, a cyclone separator is what you're after.
- If you don't have some form of a separator (cyclone or otherwise), your filters or filter-bags will clog more easily causing a reduction in airflow.

If I could vent outside with impunity I would use a bagger design and just 'let it fly' outside. Not only can I not vent outside but, I have to breath my return air so, a cyclone and a very fine filter canister is what works for me. Your environment contributes more to your decision than one might think.

[David Kumm]

Cyclones help to keep dust out of filters but come at a cost of cfm. Make sure the unit captures all the stuff at the machine before you start reducing the cfm. An oversize quality bag will increase cfm and filtration and cost about $100. Dave

[Scott Brandstetter]

Donnie
I just upgraded my dust collection. This thread may help, at least I hope it does.

http://www.sawmillcreek.org/showthread.php?237072-Dust-Collection-for-those-who-have-been-confused-like-me



Hi guys,


I'm going to take a look at a 2HP grizzly dust collector this week. i will probably pick it up, but i had a question for the community first.

Will adding a cyclone like a dust deputy ahead of the machine add any benefit? i thought i had read somewhere that this could increase the performance of DC's, but now i cant seem to find where i read that.

[Jon Nuckles]

I added a super dust deputy to my Delta dust collector and Wynn filter. I find that suction is better now because the filter stays clean and I was losing much more to a clogged filter than the cyclone eats up.

[Allan Speers]

It's also important to size the cyclone tower to the CFM of your unit.

I believe a "typical" 2 HP machine is right in-between spec for two different sized towers. Both would work, but no optimally. IIRC, Oneida has some recommendations, in terms of CFM.

I don't know where in the chain you're supposed to actually measure the CFM, nor do I know how a hobbyist would even do this. I assume some meter you'd have to buy. Someone here surely knows.

I'm probably overthinking it a bit, but it's always good to try for the optimum tuning.

[Don Kondra]

It's also important to size the cyclone tower to the CFM of your unit.

I believe a "typical" 2 HP machine is right in-between spec for two different sized towers. Both would work, but no optimally. IIRC, Oneida has some recommendations, in terms of CFM.

I don't know where in the chain you're supposed to actually measure the CFM, nor do I know how a hobbyist would even do this. I assume some meter you'd have to buy. Someone here surely knows.

I'm probably overthinking it a bit, but it's always good to try for the optimum tuning.

At the end of the hose/pipe that connects to a machines dust port. For example...

324939

Another option is to mount the fan inside a short length of pipe at the end of the run.

324938

As long as you are consistent with your testing method so you can tell what effect changes in a run, etc. actually make.

Anemometers are inexpensive, this is the one I purchased > $37.66 US > shipping took a month, sigh..

http://www.ebay.com/itm/261486368012?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Cheers, Don

[Ole Anderson]

Here I was measuring flow at my router table. 616 on my meter was 6160 fpm or 570 cfm on the 4.12" end quick fitting:

[Mike Chalmers]

I use a typical 2hp DC from Asia with a canister filter. I have a Super Dust Deputy (connected to the DC with 6" flex) on a 55 gallon drum, with a 6" main line (adapter to convert 5" port on the SDD to 6" for the main line) reducing to 4" at the machines (table saw, 8" jointer, 20" planer, edge sander, drum sander, spindle sander, band saw). I have never measured anything, but I can tell you it is a set up that works very well for me, and I am satisfied with the amount of chips and dust collected. No numbers for you, just the result of actual usage and observation.

[Don Kondra]

I use a typical 2hp DC from Asia with a canister filter. I have a Super Dust Deputy (connected to the DC with 6" flex) on a 55 gallon drum, with a 6" main line (adapter to convert 5" port on the SDD to 6" for the main line) reducing to 4" at the machines (table saw, 8" jointer, 20" planer, edge sander, drum sander, spindle sander, band saw). I have never measured anything, but I can tell you it is a set up that works very well for me, and I am satisfied with the amount of chips and dust collected. No numbers for you, just the result of actual usage and observation.

With all due respect Mike, you have gone from 5" to 6" for your main line which means your velocity will have dropped to as low as 2500 ft/min. which is borderline to keep the chips flowing.

Then you connect to 4" which results in an increase in velocity at collection but you are likely limiting yourself to about 350 CFM.

Sure, it "works" but it is not working to capacity.

A 5" main and 5" collection ports would increase your CFM to ~ 500 with a velocity of ~ 3700 ft/min .

These are actual measurements from experimenting with my system.

Cheers, Don

[Donnie Harkins]

The DC I'm looking at is rated at 1550cfm according to grizzly's website. that looks to be a lot more than even the super dust deputy is rated for. I am also looking at putting a wynn canister on it to get the 2.5 micron bag down to .5 micron. Looking at Wynn's website, it appears that adding the pleated canister filter will increase the volume of air moving thru the machine. Should i look more towards the barrel type separator? Like this one: http://www.rockler.com/dust-right-4-dust-separator-components

i want efficient collection and i'd like to keep the bag and filter as clean as possible for as long as possible... My "shop" is my garage, so cleaning up dust usually means moving everything around which isn't much fun... the more in the barrel the better.

[Don Kondra]

I think you have some research coming up Donnie :)

That 1550 CFM is without any pipes....

You will need to plan out your longest run and calculate the static pressure losses. You can download the calculator on Bill Pentz's site, look under the "Ducting" menu.

http://billpentz.com//woodworking/cyclone/index.cfm

Or do it the long way using the charts supplied with the manual of the dust collector.

Normally you would use the dust collectors performance curve graph to look up what CFM you can expect at whatever your static pressures work out to.

BTW > the separator you linked to is Not in the same league as the Super Dust Deputy.

Exactly which model collector are you looking at ?

Cheers, Don

[Allan Speers]

I think the smart way to do this is to buy that cheap anometer Don linked. Then set up your system as best you can, without any cyclone tower, but with your final filter system. Measure THAT, then talk to the cyclone sellers, or possibly use the Pentz calculation, but based on your actual reading.

I don't really know, but I'm very interested as I'm about to add a cyclone tower myself to a 1.5 HP Delta system. (And then I'm going to vent the mostly-clean air to the outside, no filters.)

[Robert Engel]

IMO the benefit of adding a cyclone is filter sparing and easier chip disposal. They talk about chips not going directly through the impeller, but I don't think this is a big factor.

A cyclone definitely degrades the cfm's of a blower.

I put a cyclone in my system and vented out side. I think venting outside if you can do it, offsets the loss a little.

I think the best case scenario is an outside vented, non-cyclone unit, but that means building a shavings and other envrionmental issues.

Depending on the extent of your system, 2HP may not be enough with a cyclone.

[Mike Chalmers]

With all due respect Mike, you have gone from 5" to 6" for your main line which means your velocity will have dropped to as low as 2500 ft/min. which is borderline to keep the chips flowing.

Then you connect to 4" which results in an increase in velocity at collection but you are likely limiting yourself to about 350 CFM.

Sure, it "works" but it is not working to capacity.

A 5" main and 5" collection ports would increase your CFM to ~ 500 with a velocity of ~ 3700 ft/min .

These are actual measurements from experimenting with my system.

Cheers, DonI take your comment "with all due respect" to heart and ask you to do the same. This response is not to start a peeing contest, simply to explain my approach (good or bad) and pass on my empirical evidence.
I have a 6" main (about 15' of 26 guage snap lock) because I installed it when I decided to "upgrade" from my 2hp & SDD set up with only 5" flex I moved from machine to machine by purchasing a 3hp cyclone from King Canada (same as the Laguna). That turned into a huge disappointment, and I returned it and reinstalled the 2hp/SDD set up using the ducting I had installed.
I do not doubt your numbers, as I have none of my own. What I can tell you is the following.

20" planer. I can see the chips going up the 6" flex that connects the 5" port to the 6" duct. They go up about 4', and then over the shop and down to a wye just before the SDD. To top it off, I have a 90 elbow and two 45s in the run. I took apart the joints a week or so ago to have a look, and there is no chip or dust in the duct.

16/32" open end drum sander. There is very little dust evident on the machine after I use it. There is quite a bit in the collection drum, and some (maybe 20%) in the canister filter and collection bag below it.

I will use only those two examples, as they are the worst offenders for the production of dust and chips in my shop. I feel if my set up was as bad as your numbers would suggest, then I would see much more at the machines. I have no explanation as to why, it just is.

Would I like a better set up? You bet. I am, however, pretty happy with what is happening now.

I may look at replacing the 6" with 5" sometime after Christmas.

[Don Kondra]

I take your comment "with all due respect" to heart and ask you to do the same. This response is not to start a peeing contest, simply to explain my approach (good or bad) and pass on my empirical evidence.
I have a 6" main (about 15' of 26 guage snap lock) because I installed it when I decided to "upgrade" from my 2hp & SDD set up with only 5" flex I moved from machine to machine by purchasing a 3hp cyclone from King Canada (same as the Laguna). That turned into a huge disappointment, and I returned it and reinstalled the 2hp/SDD set up using the ducting I had installed.
I do not doubt your numbers, as I have none of my own. What I can tell you is the following.

20" planer. I can see the chips going up the 6" flex that connects the 5" port to the 6" duct. They go up about 4', and then over the shop and down to a wye just before the SDD. To top it off, I have a 90 elbow and two 45s in the run. I took apart the joints a week or so ago to have a look, and there is no chip or dust in the duct.

16/32" open end drum sander. There is very little dust evident on the machine after I use it. There is quite a bit in the collection drum, and some (maybe 20%) in the canister filter and collection bag below it.

I will use only those two examples, as they are the worst offenders for the production of dust and chips in my shop. I feel if my set up was as bad as your numbers would suggest, then I would see much more at the machines. I have no explanation as to why, it just is.

Would I like a better set up? You bet. I am, however, pretty happy with what is happening now.

I may look at replacing the 6" with 5" sometime after Christmas.

Thanks for your reply Mike.

I think your experience, and likely the majority of other dust collector users is the same. Collection is adequate at the machine.

Your system isn't "bad". It just isn't optimized to its full potential.

I'm not suggesting you need to tear it apart but I hope others reading this discussion will be encouraged to do a little research before buying a collector and installing duct work.

For years I hauled around 20' of 4" hose and it worked well enough at collecting at source.

But fine dust filtration on the other end really wasn't satisfactory. Hence my decision to upgrade to the SDD and the Wynn filter.

I taught myself as much as I could stomach about static pressure :) and figured out how to use Bill Pentz's static pressure calculator.

Finally began to understand the relationship between static pressure/velocity/CFM and dust collector performance curve graphs.

Then I decided on my main pipe diameter and started buying components.

In hindsight I really didn't want to make the effort but I'm glad I did and know I did the best I could without spending a bunch of money.

If you do decide to change your main run to 5", shoot me a PM with your address Before you do it and I'll mail out my anemometer for you to do some testing...

Then we can talk numbers :)

Cheers, Don