Piping new-to-me DC

[Anthony Whitesell]

I picked up a Grizzly 2HP G1029 DC with the 6" inlet. I have an Oneida cyclone in boxes I picked up years ago, but have not figured out how to make the head height work yet. In the meantime, I have this to work with.

I am planning to rebuild the stand and mount to remove the 90 degree flex tubing. I am also planning to use the homemade trash can separator I built based on plans from SMC. These are the plans with the 90 elbow going into the top of the lid, the baffle in the middle similar to Thien baffle, and the outlet from the middle. I use it now with my 1HP and I like the hard bin and extra capacity.

So the questions are:

The G1029 has a 6" inlet that measures similar to sheetmetal duct 6". Does the sheetmetal duct actually match up ID for OD?

Has anyone built a trash can separator with 6" inlets and outlets? What did you use for the inlet elbow as I am at a loss to find a long radius sheetmetal elbow?

Or more exactly, if I use a 6" PVC elbow in the trashcan how do I transtion PVC to sheetmetal to connecto to the DC? PVC 6" measures 5/8" diameter larger than the sheetmetal.

[Bill Dufour]

I doubt a trashcan is big enough for 6" airflow to allow much to drop out and not be picked up.
Bil lD

[Anthony Whitesell]

Either way I am looking for options to get from the 6" actual inlet to 6" PVC.

[Frank Drackman]

Fernco 6" rubber adapter sold in most hardware stores. I recently purchased one at Home Depot for $17.00

[Jim Dwight]

I used a Thien baffle once but I am not a fan. My experience is that it was pretty effective on larger pieces but did little to reduce the need for filter cleaning. For me, that is the major reason I want a pre-separator. I believe cyclones are much more effective at removing smaller particles so you can delay filter cleaning and still have effective dust collection. So I would not "mess around" with a trash can separator and just install the cyclone.

I use the 2hp HF DC and I modified the inlet to six inch to match the super dust deputy cyclone I use. I used only the motor and blower of the HF which I mounted to the wall with only a couple inches to the ceiling (8'). That wasn't hard with the HF, I just used it's normal mounting bolts into a piece of 3/4 plywood solidly screwed to studs in the wall. My Oneida cyclone is directly below the blower and sitting on a home made collection box made of plywood. I made the box about 18 inches square which is about the space required for the motor and blower. It has about 70 gallons of capacity. I exhaust outside so I have no filter.

I am unfamiliar with your equipment but I suspect you can do something similar to what I did if you want to. If you are happy with your pre separator just taking the large pieces out before the filter then your trash can separator may work fine for you. But if you want the filter cleaning to decrease, I strongly suggest a cyclone is the way to accomplish that. My setup is such that I can add a cartridge filter by a little replumbing if I want to switch to that later (if I heat and cool my shop at some point).

[Anthony Whitesell]

Thank you all for the input so far, but we are missing the questions.

In regards to the cyclone, I cannot find a 24" diameter 12" tall collection barrel nor do I think that would be an effective way to run a cyclone.

I am not adding a Thien Baffle to the DC. I am using the trash can separator with the lid design that has the elbow inlet at the edge, the outlet in the center, and internal baffle. With this design I am getting quite efficient separation. I don't know the exact particle separation effiency, but the chips reach the baffle before they begin to enter the DC. When starting with an empty drum and connected to the sander I do get a lot of material in the drum. Again this is the visible stuff, I don't know how much of the stuff not visible to the eye makes it to the DC bags. The "trash can' is a 75 gallon barrel with a intergrated wide point for a barrel lift so it is quite a monster of a barrel.

I tired the fernco on the DC inlet, but I could not get it to seal on the DC. Too much material (circumference and thickness) to shrink (cinch up) that much in diameter.

[Jay Kepley]

I'm in the process of converting a 2 hp Jet dust collector to a two stage. I'll offer some comments that may or may not be useful to you. First, Oneida told me that a 2 hp collector cannot support six inch ducting. It indicated that a 2 hp motor will not move enough air to move dust effectively in a six inch pipe. It suggested I use five inch ducting (with its Super Dust Deputy cyclone, which I had already purchased from Woodcraft). I've purchased some five inch spiral pipe (which is very nice) from Air Handling Systems, and it fits around the exhaust port on the blower unit. I am going to use a fitting, though, that will join the duct to the blower unit. I believe that will be cleaner and allow for a better and tighter joint. Based on reading a lot of forum posts on dust collection, I understand that using a well designed cyclone will produce better efficiency and results than a Thien baffle. I obviously don't know that for certain, but that's what most folks say. Five inch ducting and flex hose is substantial. It looks a lot bigger than four inch which means it will move more air with the right blower. Hope this helps. If I've mentioned anything that you understand as incorrect, please let me know.

[Anthony Whitesell]

I'm in the process of converting a 2 hp Jet dust collector to a two stage. I'll offer some comments that may or may not be useful to you. First, Oneida told me that a 2 hp collector cannot support six inch ducting. It indicated that a 2 hp motor will not move enough air to move dust effectively in a six inch pipe. It suggested I use five inch ducting (with its Super Dust Deputy cyclone, which I had already purchased from Woodcraft). I've purchased some five inch spiral pipe (which is very nice) from Air Handling Systems, and it fits around the exhaust port on the blower unit. I am going to use a fitting, though, that will join the duct to the blower unit. I believe that will be cleaner and allow for a better and tighter joint. Based on reading a lot of forum posts on dust collection, I understand that using a well designed cyclone will produce better efficiency and results than a Thien baffle. I obviously don't know that for certain, but that's what most folks say. Five inch ducting and flex hose is substantial. It looks a lot bigger than four inch which means it will move more air with the right blower. Hope this helps. If I've mentioned anything that you understand as incorrect, please let me know.

That is interesting since the Onieda designed DC system that is too tall for me to install came with a 2HP motor 13.5" fan (IIRC) and 6" main ducting. It is Oneida's specialty, but i think some information waas relayed poorly. A carte blanche statement that a 2HP motor will not support 6" duct cannot be made. It is TOTALLY dependent on how big the system is (how much duct) and the fan curve. In my shop, the DC is centrally located with the longest run (for the table saw) being 20' maximum. Based on the spreadsheet from Bill Pentz, 6" inlet, 6" trash can separator, and 15' of smooth pipe and 5' of flex should leave me with space to burn on SP.

But first I need to find parts or ways to put humpty dumpty together, hence the questions.

[Bill Dufour]

Fernco fitting are amde for different materials at each end. I would guess 6" copper, ABS, pvc or iron pipe. Or try 5.5" cast iron or clay. Asbestos pipe of " may work.
Fernco 1003 series is 6.00" for asbestos cement pipe. Or wrap the nipple with duct tape or electrical tape for several turns until it is a good fit into the fernco.
Your measurement is not clear. What is the outer diameter of you 6" outlet? Is it 6" or is it bigger?
Bil lD

https://www.fernco.com/products/flexible-couplings/stock-couplings#tid-177

[Anthony Whitesell]

The 6" inlet does actually measure 6 inches. Orange and blue stores only had one 6" fernco, appears to be for PVC pipe to pipe as it is almost 7" ID.

[Bill Dufour]

When i had an issue getting a fernco over old cast iron in a trench I put a cherne plug into the fernco and expanded it for 30 minutes or so. Then quickly slipped it on and waited for the rubber to shrink back down before tightening the clamp. You could turn a cone to fit inside and pound it in to expand it I suppose.
Bil lD.

[Jay Kepley]

It might be because the impeller on my collector is only 12 inches. I don't dispute anything you've said. Dust collection and the air dynamics involved are intimidating to me. I'm going to do the best I can to piece something together, and hope it works well!

[Anthony Whitesell]

It might be because the impeller on my collector is only 12 inches. I don't dispute anything you've said. Dust collection and the air dynamics involved are intimidating to me. I'm going to do the best I can to piece something together, and hope it works well!
Ditto that!!

[Anthony Whitesell]

:rolleyes: Expand from 7" to 6"?

[Andy D Jones]

That is interesting since the Onieda designed DC system that is too tall for me to install came with a 2HP motor 13.5" fan (IIRC) and 6" main ducting. It is Oneida's specialty, but i think some information waas relayed poorly. A carte blanche statement that a 2HP motor will not support 6" duct cannot be made. It is TOTALLY dependent on how big the system is (how much duct) and the fan curve. In my shop, the DC is centrally located with the longest run (for the table saw) being 20' maximum. Based on the spreadsheet from Bill Pentz, 6" inlet, 6" trash can separator, and 15' of smooth pipe and 5' of flex should leave me with space to burn on SP.

But first I need to find parts or ways to put humpty dumpty together, hence the questions.

The maximum duct size is based on minimum air velocity in the duct, necessary to keep the dust/chips in suspension, rather than settling out in the ductwork. Once the dust starts settling out, it forms clumps, and when they get big enough to block enough airflow, they break loose and can damage and/or clog the system.

The actual air velocity depends on the blower, the duct size, length and configuration, and the efficiency of the filter and the separator.

It seems the wildcard here is the efficiency of the separator (not just how much dust it separates, but how much pressure drop it introduces). Conical cyclonic separators are the most efficient kind, especially compared to a trash can separator.

Therefore, simply because you have a blower, a filter and a duct length that supports 6" ductwork, you may not be able to support that duct size with a trash can separator.

Also, multi-drop ductworks can suffer from leaky blast gates reducing airflow from the open inlet(s), compared to a single non-branched run to the farthest point. Each Y fitting also adds pressure drop, due to the eddy flow in the blocked off branch.

-- Andy - Arlington TX

[Anthony Whitesell]

Therefore, simply because you have a blower, a filter and a duct length that supports 6" ductwork, you may not be able to support that duct size with a trash can separator.

You are correct. But once you know what you have, you can then do the SP loss calculations for the duct work, fittings, et al. and compare the results to the fan curve. My fan curve is a two point (SP @0CFM, and CFM @0SP), and the the trash can separator SP loss is guessed for now (actually based on what I have for the 4" DC). Given that, the math says I am good with margin.

All I have to do now is figure out how to connect the DC to the plumbing.

[David L Morse]

...My fan curve is a two point (SP @0CFM, and CFM @0SP)...

This, from a Wood Magazine test, might help fill that in a bit:

441728

[Anthony Whitesell]

I can't see the picture.

Google found this

https://www.woodmagazine.com/system/files/247FanCurveChart.pdf

for 1.5HP DCs thoough.

Is yours 1.5HP or 2HP?

[David L Morse]

I can't see the picture.


Click the "Donate" button.

[Bill Dufour]

I do not remember the exact figures but I significantly improved the measured vacuum with a simple neutral vane. Just a roll of flat sheet metal stuffed into the DC inlet. It ended up sticking in about two inches for maximum effect. Then I installed one sheet metal screw to keep it in place.
Bill D.

[Anthony Whitesell]

Click the "Donate" button.
I haven't been able to sell anything this year. So I don't have any paypal monies.

[james manutes]

Here's my 2 cents . Grizzly 1.5 , 2 , and 3 HP are all upgrades from the HF that is so common . All have a 12 3/4" impeller , with the 1.5 HP model is 10 mm shorter . I'm on my third shop built cyclone , and all three have been pretty good . We should decide I think what is "pretty good" . I've used 6" PVC on all 3 collectors , and got 775 to 875 CFM at the end 25' branches . I'm thrilled with it , but it's not up to Bill Pence numbers . Only other point is the Dust Deputy , Thien baffle , or trash can sep. add resistance , choose wisely .

[Anthony Whitesell]

Here's my 2 cents . Grizzly 1.5 , 2 , and 3 HP are all upgrades from the HF that is so common . All have a 12 3/4" impeller , with the 1.5 HP model is 10 mm shorter . I'm on my third shop built cyclone , and all three have been pretty good . We should decide I think what is "pretty good" . I've used 6" PVC on all 3 collectors , and got 775 to 875 CFM at the end 25' branches . I'm thrilled with it , but it's not up to Bill Pence numbers . Only other point is the Dust Deputy , Thien baffle , or trash can sep. add resistance , choose wisely .
How did you measure your CFM? I use the pitot tube method. I try to be consistant, but it's tough and I don't know how much error being off center introduces.

I'm still stuck looking for parts to connect the darn thing.

[Jim Dwight]

I don't have any 6 inch metal duct around, I used 5 inch. But the big box stores around here have it, the snap lock type (which is what I used, HD uses heavier gauge sheet metal). They also have fittings. So you could measure some and see what you think. If it is close but larger, tape wrapped around the DC connection might make up the difference.

5 inch fittings are not easy to find and I used "Sheet Metal Kid" for my wyes. I did not look but he might have the 90 degree 6 inch fittings you want. If you google the phrase in quotes you should find him, they are in Oregon. Otherwise the fernco would be the most elegant way to mate the PVC to metal pieces. Duct tape would be another way that is not very elegant but would probably work.

I think my little HF only has a 10 inch blower which is much smaller than your 13.5 inch. I will probably upgrade it to the Rikon 12 inch that a lot of people use at some point. The size of the blower certainly makes a difference. But if you put a 13.5 inch blower on a 2hp motor, it cannot be driven as hard as a 12 inch impeller - the motor is also a limitation in how much work can be done. (testing done by others shows the HF motor draws more current when the impeller size is increased which is the point I am trying to make. The Rikon 12 inch pushes the HF motor about to it's rating) I had a light dusting in a horizontal run of my 5 inch pipe going to my table saw when I cut into it for overhead dust collection (I put on a 3 inch wye). That makes me happy I did not use 6 inch. But your system is bigger and may work fine with 6 inch. But it is on the big side for a 2hp - but that increases airflow, it just decreases air velocity. I would expect you will have at least light dust buildup in your piping.

It sounds like your cyclone is really tall, that should make it's separation very good. But since you have a setup you like, I can see you wanting to work with that. To me it comes down to filter cleaning. I hate it, you apparently are not as turned off by the results you get from your system as I was with mine. If you wanted to make the cyclone work, it is very possible to make a 2 foot high box for dust collection. If you made a box 3 feet square by 2 feet tall it would have about a 135 gallon capacity, for instance.

[Anthony Whitesell]

The size of the blower certainly makes a difference. But if you put a 13.5 inch blower on a 2hp motor, it cannot be driven as hard as a 12 inch impeller - the motor is also a limitation in how much work can be done. (testing done by others shows the HF motor draws more current when the impeller size is increased which is the point I am trying to make.
No testing is required to know that if more load is put on a motor, the current increases.


If you wanted to make the cyclone work, it is very possible to make a 2 foot high box for dust collection. If you made a box 3 feet square by 2 feet tall it would have about a 135 gallon capacity, for instance.
Where would I put the extra 12" of height you suggest? The motor, fan, cyclone body, and cone are 6 1/2 feet tall. The ceiling between the joists is just less than 7 1/2 feet. I have not looked into what the motor requires for clearance above it for airflow (and I know it won't be 0 inches).

[Curt Harms]

Anthony, have you investigated not putting the fan on top of the cyclone but instead have some sort of ducting from the cyclone outlet to the side of the cyclone and put the blower and filters beside the cyclone? A straight shot from the cyclone outlet to the fan is optimum but I wonder if there's a way to have a rectangular duct on top of the cyclone transitioning to round for the blower inlet without too much suction loss. I guess there's not, I doubt I'm the first to have thought of this.

I have a 2 h.p. DC much like the Grizzly and use 6" PVC pipe. The PVC fit snug enough over the DC inlet that duct tape was adequate to seal it. I have a Thien baffle built into the DC, I didn't want to extra hose with its attendant pressure loss and space of a separate collector. If I empty the bag when it's about half full I don't find it a difficult task.

[james manutes]

I found an anenometer on Ebay , $39 , probably not real good . The thing to me is that w/ under-powered blowers (1.5 - 2 HP ) design is everything . Can you run PVC from the blower to the separator , that will help . Eliminate every foot of flex hose you can , from the tool's to the collection bin . I wouldn't worry about the readings of CFM w/ a trash can system , it won't be great . It will get the chips , and the fine's will pass thru . The Grizzly 1029 is a single bag , not ideal- do you have a cannister ? Under-powered DC's create the chance to "chase" the result we all want , when it is wiser to stop and get it right . The trash can is a bridge to the next solution . Time and budget drive decisions , we do the best we can .

[james manutes]

A good example of your DC converted to a cyclone is Unemployed Hillbilly Redneck Creations on Youtube . A great source for a filter is Air Cleaning Specialists ( Chris Peanick / sales ) . Mine is 13" x 34" 282 sq. ft. sur. area , $94 . Wynn Envir. isn't the only option out there . Good luck with whatever you choose .

[james manutes]

My blower w/ a Dust Deputy XL is 56" from the top of the motor to the bottom of the Dust Deputy . I've got 3' 6" for bin and discharge flex hose . Sounds like you've got a full size cyclone body on the scale of Clear Vue or a Onieda machine . I can see why you would use a trash can system for now . That 2 HP Grizzly wouldn't work well on a cyclone that size .

[Marc Fenneuff]

Where would I put the extra 12" of height you suggest? The motor, fan, cyclone body, and cone are 6 1/2 feet tall. The ceiling between the joists is just less than 7 1/2 feet. I have not looked into what the motor requires for clearance above it for airflow (and I know it won't be 0 inches).

I was in the same boat and could not fit any off-the-shelf trash can under my cyclone, so I had to build a box out of 3/4 ply. So far it works fine even though it is only about 20” tall.

441941

[Anthony Whitesell]

Anthony, have you investigated not putting the fan on top of the cyclone but instead have some sort of ducting from the cyclone outlet to the side of the cyclone and put the blower and filters beside the cyclone? A straight shot from the cyclone outlet to the fan is optimum but I wonder if there's a way to have a rectangular duct on top of the cyclone transitioning to round for the blower inlet without too much suction loss. I guess there's not, I doubt I'm the first to have thought of this.
Yes, I have. The height of the motor and blower is equal to the take-out of the 8" elbow. So there is no height reduction. The upside is I don't need any extra space for motor cooling. I gain about 4-5".



I have a 2 h.p. DC much like the Grizzly and use 6" PVC pipe. The PVC fit snug enough over the DC inlet that duct tape was adequate to seal it. I have a Thien baffle built into the DC, I didn't want to extra hose with its attendant pressure loss and space of a separate collector. If I empty the bag when it's about half full I don't find it a difficult task.
"The PVC fit" Is that PVC pipe or PVC fitting? If it is PVC pipe, is it SCH40 thick wall or the thin wall SDR?
?

[Tom Bender]

So you want to reduce the ID of the PVC by 5/8".

Cut a piece 2" long and cut a short section out of it. Squeeze this into the end of your PVC pipe to reduce it. If it's now too small enlarge it on the lathe or with a router or rasp. Probably want to do that on a longer piece. You may end up making 2 or 3 before you get it just right. You can taper the inside end for better flow.

[Bill Dufour]

Tom, I used that method to reduce from 6" to 5" at the cyclone. I took a piece of 6" about 18" long and did the math to cut a wedge out that tapered from nothing to the difference in circumference at the small end. Was that 3.14157" I took out? 15 years latter it still has three hose clamps since I do not trust the glue up.
Bil lD

[Anthony Whitesell]

A good example of your DC converted to a cyclone is Unemployed Hillbilly Redneck Creations on Youtube . A great source for a filter is Air Cleaning Specialists ( Chris Peanick / sales ) . Mine is 13" x 34" 282 sq. ft. sur. area , $94 . Wynn Envir. isn't the only option out there . Good luck with whatever you choose .

I do not need to convert the Grizzly to a cyclone. I have an Oneia cyclone system in boxes already. I have not yet figure out how to set up the Jolly Green Giant in Papa Smurfs short house.

[james manutes]

Anthony , my bad . I thought your dilemma was to use that cyclone body - probably a Dust deputy . I see what you mean now .

[Curt Harms]

Yes, I have. The height of the motor and blower is equal to the take-out of the 8" elbow. So there is no height reduction. The upside is I don't need any extra space for motor cooling. I gain about 4-5".


"The PVC fit" Is that PVC pipe or PVC fitting? If it is PVC pipe, is it SCH40 thick wall or the thin wall SDR?
?

The pipe itself fits on the DC inlet. I'm not real sure about the pipe, I'm pretty sure it's not SCH40 but it's also not real thin wall like some 4" S&D that I have. I kinda thought all PVC pipe was the same I.D., the O.D. varies but I could be mistaken in this.

[Anthony Whitesell]

My blower w/ a Dust Deputy XL is 56" from the top of the motor to the bottom of the Dust Deputy . I've got 3' 6" for bin and discharge flex hose . Sounds like you've got a full size cyclone body on the scale of Clear Vue or a Onieda machine . I can see why you would use a trash can system for now . That 2 HP Grizzly wouldn't work well on a cyclone that size .

Anthony , my bad . I thought your dilemma was to use that cyclone body - probably a Dust deputy . I see what you mean now .

The cyclone is the previous generation C950 (with 12" diameter hard flange for the box connection) with a 2HP Marathon motor and 13" impeller.

[Tom Bender]

Not suggesting making a tapered piece of PVC, though that can work. My suggestion was to slip a 2" long piece inside the too large pipe to reduce the ID.

[Anthony Whitesell]

I got to us the new-to-me DC with the 4" duct work and the trash can separator. Separation is good, with enough airflow the can doesn't clog when it gets full (LOL). My can is now full to the baffle.

4" duct work I learned long ago (I've been on SMC for 13 years) should be outlawed and illegal to sell, classified as a scam. I need to figure if I should go with 5" metal or 6" PVC.

I thinking PVC because it is more 'machinable' and
1. I want to make my own blast gates
2. I want to automate the blast gates to get them out of the way and where I couldn't reach them (I already have one I can barely reach)
3. I like the look of the fazlok twist and lock hose coupling and would like to make my own. I have only found them in 4" and appear to be made of, weak, acrylic plastic.

I noticed at Woodcraft today some 5" ABS plastic fitings. Is there such a thing as 5" PVC?

[Ryan Yeaglin]

Clear view makes tube to pipe adapters, the shipping is stupid though. Better yet, call your local trade school that has a sheetmetal shop. Get a 6"x 6 5/8" round to round reducer made 10" long with 2" long collars. Should be pretty cheap if they get a student to make it. Or a local sheetmetal shop.

[Steven Cooper2]

Do you have a 3d printer or a desire to have one? I have one I have probably printed out hundreds of dollars worth of random dust collection fittings and adapters, more than paying for the printer by this point I'm sure.

I just printed up a couple 6" fittings for maybe $5 each. Probably not great for water, but good enough for dust.

[Anthony Whitesell]

Do you have a 3d printer or a desire to have one? I have one I have probably printed out hundreds of dollars worth of random dust collection fittings and adapters, more than paying for the printer by this point I'm sure.
I just printed up a couple 6" fittings for maybe $5 each. Probably not great for water, but good enough for dust.
Interesting thought. I'm not sure 3D printing 5" pipe is the way to go. :)

[Charlie Jones]

Anthony, When I installed my Clear Vue system, I used 6” PVE sewer and drain pipe. I made some y’s and adapters by heating the pipe until it was pliable. I cut openings and fitted the pipe together and sealed it with duct mastic. By the time I finished, I had got quite good at it. You could easily make your adapter this way. Just run a propane torch around the pipe, staying far enough away to not set it on fire. At some point it will be soft enough to do what you need with gloves.

[Anthony Whitesell]

I got to us the new-to-me DC with the 4" duct work and the trash can separator. Separation is good, with enough airflow the can doesn't clog when it gets full (LOL). My can is now full to the baffle.

4" duct work I learned long ago (I've been on SMC for 13 years) should be outlawed and illegal to sell, classified as a scam. I need to figure if I should go with 5" metal or 6" PVC.

I thinking PVC because it is more 'machinable' and
1. I want to make my own blast gates
2. I want to automate the blast gates to get them out of the way and where I couldn't reach them (I already have one I can barely reach)
3. I like the look of the fazlok twist and lock hose coupling and would like to make my own. I have only found them in 4" and appear to be made of, weak, acrylic plastic.

I noticed at Woodcraft today some 5" ABS plastic fitings. Is there such a thing as 5" PVC?

[Steven Cooper2]

Interesting thought. I'm not sure 3D printing 5" pipe is the way to go. :)

Well, not the pipe, but it seems that there are always things that are closeish or you need some not quite right adapter, flange etc that doesn't seem to be available. I'm quite happy with the integrity of my 6" printed fittings, though I have not tried anything larger than that...

[David M Peters]

I'll try to answer one of Anthony's original questions albeit a few months late.

I transitioned from 6" 2729 PVC to my 2HP Jet cyclone inlet (~5-7/8" OD) with a turned adapter. I was all jazzed to buy a 3D printer for this task when I realized that my lathe is more than capable of making cylinders... darn common sense got in the way of a fun tool.

445792

I made a series of plywood rings (bandsawn circles with middles cut out with a jigsaw) and glued them into a stack and then glued that onto a waste block. Then I hollowed out the two halves with the appropriate ID using my Elbo hollowing tool.

The 6" (nomimal as heck) Fernco fitting I found at the hardware store is designed to fit around 6" clay so it was quite sloppy even around the PVC. Fernco's better sized to this application were $40+ from plumbing suppliers.

[Anthony Whitesell]

If the duct work is over sized, then the dust will fall out an collect in the duct. I would think there would be a 'terminal velocity' type aspect involved. If you have a a DC that can only support 6" duct and you install 8" duct, dust will collect in the pipe until there is 6" pipe worth of opening. The 8" duct with 50 sq in opening would be reduced to 28 sq in (6" duct).

If you can't have the exact right duct size, is it better to be the next size lower or the next size larger?

[Jim Becker]

If you can't have the exact right duct size, is it better to be the next size lower or the next size larger?

I'd go next size higher, with the qualifier that I use metal duct which is available in 1" increments. My 2hp Oneida system has a 7" port and I have 7" duct out to the major branch for the main and 6" from there. I'd settle for some slight settling over restricting max CFM...but that's a personal point of view.

[Anthony Whitesell]

I'd go next size higher, with the qualifier that I use metal duct which is available in 1" increments. My 2hp Oneida system has a 7" port and I have 7" duct out to the major branch for the main and 6" from there. I'd settle for some slight settling over restricting max CFM...but that's a personal point of view.
That was what I was thinking but wanted to check if there was something I was overlooking or not considering.

[Anthony Whitesell]

I'm thinking 6" PVC is the way to go. If oversized, dust will only settle to some terminal amount.

6" flex and 6" hoods would be overkill. Is there really that much difference between a 5" and 6" port on a 12" planer? Plus I have 5" flex on hand. I can make my own 6" PVC blast gates, with quick connect fazloc style couplings easy enough. I really only have one issue left (besides an inexpensive local source for 6" PVC LOL).

Is anyone running 6" PVC with 5" flex to the machine? How did you go about making the transition?

[Anthony Whitesell]

I have pretty well decided to use 6" PVC with 6" home made (and eventually automated) blast gates. The given the DC specs say it should be able to handle 6" duct, as many have said the ratings are probably over stated. I would expect the DC to run 5" duct like a champ. I'm going with 6" to reduce friction and SP loss and I will deal with whatever settling occurs in the horizontal runs.

I will be using the DIY trashcan separator with the baffle and center outlet. Eventually I'm thinking I should switch to the Oneida Dust Deputy. First off, it would make the trash can able to hold more (changing from working as part separator-part bag to working as all bag) and secondly the dust deputy probably works better than my trashcan version (less SP and CFM losses). I'm leaning towards the 5" version based on the above and the below.

I was gifted many many feet of 5" flex to connect to the machines. I'm sorry to say, I'm not modifying the integrated cover to my $1200 drum sander (it will stay 4").

I have a few things left to figure out.
1. Assuming I go with the 5" Dust Deputy. I will use a metal transition from the 6" DC to the 5" flex to the dust deputy. That leave the dust deputy inlet side. How do I convert from the 6" PVC (6 5/8" OD) to the 5" flex hose for the dust deputy inlet?
2. Same as #1, only from the blast gate to the hose to the machine. No matter how show the hose is, it is still hose, and still needs a connection. :)
3. Dust hoods. The bandsaw needs a 544 wye, hoping I can find one. The drum sander will stay 4". I need to make 5" dust ports on the jointer and table saw. I prefer something with a thicker edge than sheetmetal, I've already cut myself just looking at the fittings. Nordfab is so tempting but twice as expensive as tempting.

Any thoughts or links on these last few items is appreciated.

[Jim Becker]

If you can retrofit the inlet on the blower to 6" and keep everything at 6", you may have better performance than with the transitions from 6" back to 5". The cyclone is already going to add some performance degrade to the setup (which is normal). Many DC's have a removable flange on the inlet of the blower which you can replace with a slightly larger one. Lots of folks have done this over the years.

[Anthony Whitesell]

The blower inlet is 6" already. But as mentioned by others, the DC likely cannot support 6" at the correct CFM. Getting a 6" dust deputy is not out of the question. But as cyclones are sensitive to airspeed, I am hesitant if the DC will be able to run within the airflow range (no idea what that range is) of the dust deputy.

That would add question #4. How to transition from 6" PVC to 6" flex (or 6" metal duct)? The transitions from the PVC to the flex hose are my current hang ups before pulling the trigger on buying stuff.

[Jim Becker]

One method to transition from the plastic to the hose is to get some flat sheet metal and cut a piece that you can make a sleeve that slips into the plastic duct, get fastened with screws or pop rivets. The hose can then be clamped to the insert securely.

[Anthony Whitesell]

I'm still stumped on how to use PVC duct and DC flex hose. At some point you need to use flex to get to the machine, or at least I do since I have to move everything around.

There was one suggestion to get from 6" PVC to 6" flex by using a 6" metal duct piece as a inner-coupling. I'd like to stay with 5" flex since I have it and think 6" flex will be too much for the DC based on prior comments.

Which type of duct do the 5" metal blast gates fit?

Which type of duct do the 5" abs gates fit? Slightly important seeing as they don't make many 5" abs fittings.

[Jim Becker]

You can use a metal reducer, perhaps with some modification, to get from your 6" plastic duct to 5" flex. The typical black ABS blast gates are not necessarily sized for hard pipe just like the other black dust collection fittings sold in woodworking stores...they are "ancient things" and often sized to work just with flex hose on both sides, which is inefficient. A lot of folks make their own blast gates for plastic ductwork.

[Thomas Kestas]

Don't overthink it. Go buy a couple of 6" pre-crimped stove pipe couplers at the hardware store. Then drill out the rivets. Add a little english to the connections you need to make (perhaps with a few german expletives), then wrap it good with some foil tape and you are done. Ready to make some dust!

Sheet metal is plastic...I used to bend sheet metal for a living. These stove pipe couplers with foil tape are the fastest way to make a duct connection on a DC system like this. Because it is all pre-crimped on both ends and you are just rearranging it a little bit making it fit. Who cares if the fitting is black?

I went through this scenario with my HF DC to Super Dust Deputy 2 stage and it worked brilliantly. Also, if the end of the pvc elbow is 5/8 too big, it needs a small section of pvc pipe put into it as a coupler. I use 4" SDR35 green sewer pipe in my system, with powertec-style black couplers and blast gates, and it all fits together magnificently with the green sdr sewer pipe. It all fits so well that I seal my duct connections with one (1) wrap of black electrical tape. You read that right.

Furthermore, if you have not tried it much, know that PVC pipe is ultra plastic and can be very easily stretched over larger fittings if you heat it up. I make all my own vacuum hose couplers out of PVC by heating with a cheap HF heatgun and working it over the fitting. Don't make it smoke...not that hot. It isn't crack; it's polyvinylchloride. But you can work magic with this technique. These homemade fittings are some of the most beneficial things in my shop.

My $.0.02. I hope it helps someone.

[Anthony Whitesell]

Does 5" plastic pipe even exist? I have found a bunch of 5" abs gates and flex hose, but no pipe or other fittings.

[Jim Becker]

Does 5" plastic pipe even exist? I have found a bunch of 5" abs gates and flex hose, but no pipe or other fittings.

"Generally speaking", no. In the common PVC/ABS pipe types that are used by folks for the "alternative use" of dust collection, it's pretty much even numbers. I think that PVC electrical conduit may come in 5" based on my memory of someone mentioning that, but that's pretty heavy stuff, not like the S&D pipe that's preferred by people wanting to use plastic for their DC duct work.

You can get pretty much any size in 1" increments from 3" up in metal duct, however, whether it's snap-lock, spiral or quick-clamp.

[Anthony Whitesell]

"Generally speaking", no. In the common PVC/ABS pipe types that are used by folks for the "alternative use" of dust collection, it's pretty much even numbers. I think that PVC electrical conduit may come in 5" based on my memory of someone mentioning that, but that's pretty heavy stuff, not like the S&D pipe that's preferred by people wanting to use plastic for their DC duct work.

You can get pretty much any size in 1" increments from 3" up in metal duct, however, whether it's snap-lock, spiral or quick-clamp.
As I mentioned that is what I found but thought I was missing something since there are 5" blast gates and flex duct readily available on the market.

From Bill's spreadsheet and other information, 5" duct would be optimal. Except for a few items. I don't really want to deal with sheetmetal. I am planning on making FazLok-style connectors and my own automated blast gates (pneumatic or electrical still TBD).

If I upsized from 5" to 6" what are the draw backs?
The SP will be minimized and the CFM will run at the max though the FPM may be compromised.
Some dust may settle, but only settle to the point that the duct ID becomes optimal. I don't think clogging will be an issue.
6" duct is huge (the OD is like 6 1/2").

Does 6" flex hose fit over the OD of 6" PVC?

[David L Morse]

Does 6" flex hose fit over the OD of 6" PVC?

Typically no, but most will fit inside a 6" coupling if you cut some threads for the wire spiral.

468870

[Ron Selzer]

Does 5" plastic pipe even exist? I have found a bunch of 5" abs gates and flex hose, but no pipe or other fittings.

5" plastic pipe is out there but the price is way up there, cheaper to buy Nordfab
5" x 5' pvc sch 40 $188.39 pvcfittingsonlinedotcom
home depot has some fittings listed online but no pipe

[Alex Zeller]

You may find 5" PVC conduit at a local electrical supplier cheaper than 5" pvc pipe.

[Michael Schuch]

I'd go next size higher, with the qualifier that I use metal duct which is available in 1" increments. My 2hp Oneida system has a 7" port and I have 7" duct out to the major branch for the main and 6" from there. I'd settle for some slight settling over restricting max CFM...but that's a personal point of view.

I have been struggling over having a larger main line than the branches. I have been thinking about exactly what you have with a 7" main line and 6" branches. If I only use 1 tool at a time and only have one gate open at a time is there any advantage to have the 7" main line? A 7" main line or bigger makes sense to me if I had more than one gate open at a time but being a one man shop it seems like a 6" main line would be sufficient??? I certainly wouldn't want to go down to a smaller duct diameter. Most of my machines only have 4" dust ports except my new to me table saw has a 6" port.

I have a used 3hp 3ph blower on a fair sized cyclone out of a professional wood working shop that closed. They had the most cobbled together ducting I have ever seen with 3 or 4 different types of pipe including metal, HVAC duct and different sizes and different wall thicknesses of PVC.

[Ole Anderson]

Michael, if you have longer horizontal runs going up to a 7" main definitely has benefits, mainly less friction losses, therefore more airflow. 800 cfm airflow on a single machine is not out of the question. I pull that much or more with my 2 hp Oneida SDG (same as Jim) with my TS, 5" bottom, 3" top connection. 6" pipe size on your vertical runs would be recommended to increase velocity a bit to be able to pull small offcuts along with the dust and chips. 800 cfm in a 7" duct will get you almost 3000 fpm velocity, the same flow in a 6" pipe will get you a bit over 4000 fpm velocity but at the cost of more friction losses..