Cyclone duct transition & other Q's??

[Rick Moyer]

I apologize for some questions that probably are answered on this forum already, but I got tired of searching:o. OK here goes:

1. I have a G0440 2hp Grizzly cyclone, which has a 7" port. I plan on using 6" S&D so what do I need to transition from 7" to 6"? I'm guessing there isn't a S&D 7"-6" adapter.

2. I plan on running 6" as far as I can and then 4" to the machines, so I suspect I will use 4" gates, or should I be using 6" gates before the 6"-4" transitions?

3. can I get 6"-4" S&D adapters?

4. What about blast gates? Is it better to make your own or purchase? I would appreciate info on either.

5. the cyclone port is 5-6 ft off the floor. The first ten feet out will have some drops along the same wall and then I will have to L across the room for another drop. Should I go up to the ceiling asap from the outlet, then drops to machines and across the room, or could I go straight out the first ten w/drops and THEN go up and across. I guess a pic would help. I'll try to get one tomorrow.

I got a great deal on the cyclone over a year ago and still have it sitting in the corner assembled but not hooked up. It's time to get things done.

[glenn bradley]

1. I have a G0440 2hp Grizzly cyclone, which has a 7" port. I plan on using 6" S&D so what do I need to transition from 7" to 6"? I'm guessing there isn't a S&D 7"-6" adapter.
I have the G0440. I used a 6" PVC coupler. The outer diameter fit snugly into the 7" opening (http://www.sawmillcreek.org/attachment.php?attachmentid=108343&d=1233111270) while the inside diameter (of course) fit the 6" ASTM-2729 pipe I used for duct. I put a small bead of silicone along the lip where the coupler entered the metal 7" opening to the blower but really don't know that it was necessary.


2. I plan on running 6" as far as I can and then 4" to the machines, so I suspect I will use 4" gates, or should I be using 6" gates before the 6"-4" transitions?I used 6x6x4 wyes and put the 4" gates in the 4" leg. This pic shows plastic gates (http://www.sawmillcreek.org/attachment.php?attachmentid=126730&d=1251762651) but, I have since switched to self cleaning metal gates.


3. can I get 6"-4" S&D adapters?I purchased 6 to 4 in PVC. I couldn't find them in a lighter weight. I only have one. My other terminations are 6x6x4 wyes with a cap on the end-point 6" leg for cleanout. You can see how I used a small section of 4" thin wall as an adapter below:

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4. What about blast gates? Is it better to make your own or purchase? I would appreciate info on either.Making your own is not difficult. Rockler and others have metal ones on sale at a very reasonable price several times a year. I just picked some up for about $6 each.


5. the cyclone port is 5-6 ft off the floor. The first ten feet out will have some drops along the same wall and then I will have to L across the room for another drop. Should I go up to the ceiling asap from the outlet, then drops to machines and across the room, or could I go straight out the first ten w/drops and THEN go up and across. I guess a pic would help. I'll try to get one tomorrow.This will be open to comment. My layout required that I go down right away. The one thing I will say is avoid elbows and use dual 45's to create a more gradual turn where possible. You may want to check out my install thread here (http://www.sawmillcreek.org/showthread.php?t=96974). Several other owners chimed in before, during and after my install. Very helpful gents.

[Rick Moyer]

Thanks Glenn. I knew you had this unit and hoped you would post. I also had found your links after I posted my questions. I suspect I can run the ducting pretty much however I wish as the main run will be mostly horizontal and the whole system isn't very involved. Shouldn't drop my cfm's much.

Q for everyone:
I could use some more info regarding building my own blast gates; or even my options on purchasing gates. What have you found to be to your liking? Anything I should be aware of?

[david brum]

It's hard to justify making your own blastgates when you can buy them so cheaply from these guys: http://http://www.blastgateco.com/Cast-Aluminum-Full-Blast-Gates.htm

I'm sure others will comment more thoroughly, but you really should look at making your machine ports 6". You will lose more than half of the airflow which you just paid for if you use the existing 4" ports on your machinery.

[Jim O'Dell]

Rick, here is a tutorial I did on making blast gates. http://www.sawmillcreek.org/showthread.php?t=42643&highlight=BUILDING+BLAST+GATES These are the self style and once you get a way to cut the holes down pat, it goes very quickly. I used a router and a home made circle cutter and did test fits in scrap material until I got a tight friction fit on the pipe. I used S&D throughout the system, mostly 6", but did some 4" as well. All of the blast gates are 1/4" MDF slides and 3/4" MDF or the melamine covered chip board I refer to in the tutorial except the last one, and I did it out of what I think is plexiglass and used some PTEG scraps Ed Morgano was kind enough to send me to play with. This one I use for my overhead guard/pick up at the table saw. Hope this helps. Let me know if you have any questions. If I don't see the thread, PM me to wake me up! ;) Jim.

[Eric DeSilva]

My $0.02, FWIW:


2. I plan on running 6" as far as I can and then 4" to the machines, so I suspect I will use 4" gates, or should I be using 6" gates before the 6"-4" transitions?

I did the same thing, although I tried to go 6" all the way to some machines--for my Unisaw it was a bit complicated to go 6", but I did it (http://www.sawmillcreek.org/showthread.php?t=137928). The jointer was easy--just replaced the existing flat-plate-with-a-metal-4"-outlet with a small piece of ply with a 6" blast gate screwed directly to it.

For blast gates, I'll throw in a plug for the clearvue 6" gates. They are injection molded plastic screwed together, and have held up a lot better than the glued 4" ABS plastic gates I got from WC. It is also easy to take them apart--which made making my unisaw box and jointer conversion a lot easier.


4. What about blast gates? Is it better to make your own or purchase? I would appreciate info on either.

For blast gates, I'll throw in a plug for the clearvue 6" gates. They are injection molded plastic screwed together, and have held up a lot better than the glued 4" ABS plastic gates I got from WC. It is also easy to take them apart--which made making my unisaw box and jointer conversion a lot easier. They are also a lot cheaper in bulk than any other gates I found.

Here's a link: http://www.clearvuecyclones.com/index.php?main_page=product_info&cPath=2&products_id=12


5. the cyclone port is 5-6 ft off the floor. The first ten feet out will have some drops along the same wall and then I will have to L across the room for another drop. Should I go up to the ceiling asap from the outlet, then drops to machines and across the room, or could I go straight out the first ten w/drops and THEN go up and across. I guess a pic would help. I'll try to get one tomorrow.

I think conventional wisdom would be to have as much of a straight run to the inlet of your cyclone--helps with establishing the circular flow or something. That said, you have to do what you have to do; I wouldn't let that slow you down too much.

What I did was come straight out, but then had a 6/6/6 wye, so I've got about 5' of straight pipe, the wye, then a 6" blast gate attached to another 5' run of straight pipe across. The wye also has a 6" pipe coming off at 45*, which runs to the ceiling, and then comes out at 90* from the ceiling. I probably should have used a pair of 45s to lower the angle where it leaves the wall to go across the ceiling, but like I said, you do what you have too...

[James Benson]

The CFM for a 4" hose is roughtly 350 CFM at best. A 6" hose is 700 CFM more or less. If you can do it use the larger hose. You will get the airflow that is needed to pick up the small micron particles that do dammage to your lungs, between 1 & 10 microns. There is someone here that enlarged all there machine ports to 6" and found out that his shop was much cleaner and his cyclone worked better after doing it. Someone here may recall whom it was.:) JB

[Rick Moyer]

I spent some time today raising the cyclone up about 10" to the top position on the stand. Here is a pic of where things are. All tools you see are movable. Most of what will get hooked to the DC is there. So, I 'm not too sure I'll need 6" all the way to the tool ports as the runs will be pretty short. The exceptions will be the TS across the room, as well as the CMS that I sit on the bench when it's needed. I don't have much usable wall space so most tools get pulled away from the walls for use.
I'm thinking a 45 connected to the cyclone inlet to get the duct up to the ceiling. Then about 6' of trunk line along the wall, then elbowed across room to TS. In that first 6', should I have one drop then branch horizontally to each machine, or should I have several drops right from the top? I'd like to save the wall space for french cleats for hanging stuff if it doesn't matter about the DC. The other three walls are 1) two oh garage doors 2) lumber racks attached to wall 3) a NYW hutch and entrance door so the wall space is limited.Plus the OH doors limit wall useage where their mounting hardware hangs.

[Leo Graywacz]

4" drops are generally to small for most machines that are designed for a dust collector (as opposed to a vacuum). I have a 2 1/2 HP Oneida cyclone and it to has a 7" inlet. I used about 5' of 7" and then dropped to a 6" for my main trunk. All of my drops to machines are 5". This gives ample CFM to the machine. Most of my ports on my machines are 4" and I have a reducer right at the port of the machine to keep the ducting as large as possible.

http://fototime.com/34B3BAF32E6CC7E/standard.jpg

http://fototime.com/B3ECEAFDC0DD87C/standard.jpg

[Rick Moyer]

To be more clear, I wouldn't use 4" until I was right at the machine. I was wondering if I should drop one 6" drop then branch horizontally,or more 6" drops.
Leo, I see that you use quite a bit of flex hose. I guess I could have some of those tools in the middle of the room if I used flex drops as you have. I was concerned about the drop in static pressure from the longer flex hoses. I was thinking I would use short flex hose after the blast gates to the machines, but I see you have the blast gates right at the machine ports. Of course my ceiling is half as high as yours:eek:.

[Leo Graywacz]

I used enough flex to have my machines move around in their particular area. The jointer flex hose has been shortened by about 3' when I added a solid duct to the upper down drop. The tablesaw can be moved around quite a bit depending on what space I require for producing cabinets. Same with the shapers, about 5' of flex so I can pull them out and use them without interference from the other shapers.

[Jim O'Dell]

It is my understanding, and correct me if I'm wrong, but it doesn't really matter how far you run 6" ducting. If you choke it down to 4" at the tool, you have limited yourself to the CFM that the 4" pipe will do, no more. The idea of running 6" pipe all the way to the machine is to enlarge the port at the maching to accept the 6" pipe. That way, you get the full capability of the CFM the 6" pipe will allow. Running a 4" hook up then going to a 6" pipe will drop the air speed in the 6" pipe, and could drop some of the debris out of the air stream, especially on horizontal runs, UNLESS there is another 4" blast gate open feeding the same spot in the 6" pipe so the air speed stays up.
My cyclone is 6" input, so I run 6 all the way. I've never understood why some manufacturers recommend 7 to 10" (what ever size input their cyclone is designed for) for the first 8 to 10 feet, then drop down to 6". Again, the system is now limited to the CFM a 6" pipe will handle. Now, I could understand in an industrial setting, the larger pipe for the first couple of drops, then reduce for the next few drops, the even reduce again for another 1 or 2 drops IF several of the drops would be in use at the same time. For most of us one man shops, this scenario just doesn't exist. If the cyclone/dust collector can utilize the larger pipe, then use it. Does this make sense? I mean, I'm no guru on this in a scientific way, but it just seems like common sense to me. (Doesn't mean it's not off base :D )
I do have some 4" drops to tools that I'm not ready to modify (lunch box planer-can't see it would help given the chip door is only about 2 X 3") and the BS that I see no way to modify. (Might add another 4" right under the table at some point in the future to catch what's thrown off the blade there). But both my new cabinet saw, and the old contractor saw, as well as the router table all have 6" hookups.
I don't mean to be adversarial here, just my thoughts based on common sense. Jim.

[Chris Parks]

It is my understanding, and correct me if I'm wrong, but it doesn't really matter how far you run 6" ducting. If you choke it down to 4" at the tool, you have limited yourself to the CFM that the 4" pipe will do, no more.

Spot on. Where did the idea of changing pipe diameter come from? The last thing any domestic system needs is a pipe reduction below 6", anywhere, unless it is multiple feeds into one 6" branch ie two 4'' which while a bit lower in total diameter than one 6" but is close enough. Can someone please tell the machine makers that 4" is not good enough for efficient dust and chip collection. Of course the above is all dependent on having the blower capacity to run and some are not that fortunate. In the end good dust collection on a budget is very difficult or nearly impossible to achieve and another thing, dust collection and chip collection are two distinctly different things though achieved at the same time.

[Leo Graywacz]

Changing the diameter of the duct serves a definite purpose. Because ducting with airflow through it creates static pressure there is loss of the speed of the airflow through the ducting. As you get farther from the DC the speed of the air will get slower. By decreasing the diameter of the ducting you increase the ft/min airflow. Your target airflow should be about 4000 ft/min. If the airflow becomes to slow in the ducting you will get dropout of wood chips. This is one reason why you downsize your machine drops. You need the extra airspeed to get the heavier chips to flow vertically against gravity.

[Jim O'Dell]

Leo, that very well may be true for many systems/installs where there is a lot of loss due to pipe and fittings, or cyclones that are on the lower power scale. I'm fortunate that my runs are short and I have probably way more power in the cyclone than I really need. My longest run is about 28 pipe feet from cyclone input to machine hook up. (The machine is only about 14 linear feet away from the cyclone.) So I tend to think in terms of my system which doesn't take into account the overall picture. Jim.

[Chris Parks]

I am with Jim here. If the fan/motor isn't sized to run 6" to the machine without any noticeable drop in air speed it is not going to control the spray of dust from the machining process and that is the absolute primary objective. It is the dust that does the damage, the chips can be swept up and it is the dust that must be collected at source. BP has been banging on about this point for years but I doubt that anyone has really listened. Everyone assumes the prime reason for a DUST COLLECTION SYSTEM is to keep the workshop clean and if they successfully collect all the big bits there are no small bits left to worry about. Sadly that is not the case and it is a bit more involved than just air speed, we need the air speed to be about 4,000 FPM at a high volume which can only be met by using 6" (just) and preferably 8" but I think 8" is not practical in a normal workshop and bloody expensive to boot.

[Rick Moyer]

Well, I think I'll use 6" as far as I can, but some tools will be too hard to modify to 6" ports. Anyway, my local supplier (US Supply) charges the following:
10' pipe $12.32 vs. $28.16 Mcmaster Carr
coupling $3.88 vs. $7.23
but, their prices on wye's and elbows is more than McMaster Carr
6x6x6 wye $29.57 vs. $15.40
45 elbow $15.16 vs. $11.29

go figure! Just gotta decide how much of what I need.

Jim, you got any pics of enlarging your machine ports, or instructions?

[Jim O'Dell]

Rick, if you filter through my shop rehab thread here: http://www.sawmillcreek.org/showthread.php?t=14427&highlight=coolmeadow+shop+rehab You'll find how I did the Ridgid contractor saw mod, the router table set up, and the new Grizzly G0691 table saw. Like I said above, the Band Saw can't be modified, but I may add some type of hood under the table and put a second 4" pipe there. My Delta lunchbox planer will stay 4", even though there are some who have built hoods that accept 6". But the little chip extraction window from the cutter head doesn't make that very practical. I still haven't totally designed the hood for my SCMS/RAS station, but it will have a 6" hook up there, as well as a separate hook up to the shrouds, probably via a whole house vac set up I got for free. Jury is still out on that though. The future jointer should be easy to modify from 4" to 6" if I get the one I'm thinking of, but that will probably be a year or 2 down the road. Jim.