HF Dust Collector Pipe Size

[Stew Hagerty]

Hey everyone, just looking for a few good ideas...
I have the HF DC and it comes with a Y that has 4" inlets. However, without the Y the inlet is 5". So, I am pitching the Y and definitely going to run main lines that are at least 5". My question is this: Is there any advantage to running main lines that are larger, such as 6" or 7", when I would have to reduce down to 5" back at the collector?

[james glenn]

I cut the opening to fit a 6" main and went that way. It was easier an cheaper to get the 6" piping and parts as opposed to the 5".

[lamar bailey]

James how did you cut the opening do you have any pictures?

[Bob Riefer]

Just to present another option for you. The dust collector police will yell at me for using 4" pipe, but that's what I did (you see, I rebel against authority). I just wrapped some rubber tape around the end of a coupling to make it a bit wider, and then it wedged into the opening nicely. Foil tape then holds it in place and ensure air tight seal.

[Stew Hagerty]

I cut the opening to fit a 6" main and went that way. It was easier an cheaper to get the 6" piping and parts as opposed to the 5".

Like Lamar, I'm curious about how you cut and fitted it for 6" piping. And I too would love to see pictures.

[Stew Hagerty]

Just to present another option for you. The dust collector police will yell at me for using 4" pipe, but that's what I did (you see, I rebel against authority). I just wrapped some rubber tape around the end of a coupling to make it a bit wider, and then it wedged into the opening nicely. Foil tape then holds it in place and ensure air tight seal.

So you used 4" for everything? Has the suction been sufficient?
I'm curious, why did you go through the rubber tape thing? Didn't you have the suppied "Y"? Or, is there a specific reason you did it that way?

[David Hostetler]

I ran with the 5" to a wye, then I ran an upper, and a lower 4" circuit, and it works fantastic... I get collection at the top and the bottom. While I don't have all of my machines 100% figured out DC wise, I have come a LONG way doing it this way... Even if I ran a 6" main, I would still split off to 2 branches so I can get dust AT the source...

[james glenn]

James how did you cut the opening do you have any pictures?

I basically traced out the 6" circle, then cut it with a metal blade on the jigsaw.
Then I used carriage bolts to mount a piece of 3/4" ply with the pipe adapter to the unit. Checked
to make sure the impeller didn't hit anything.

I am actually on vacation, but can post pictures when I return home in a week.

[Bob Riefer]

stew wrote:


So you used 4" for everything? Has the suction been sufficient?
I'm curious, why did you go through the rubber tape thing? Didn't you have the suppied "Y"? Or, is there a specific reason you did it that way?


Yes, I used 4" for everything. You will hear lots and lots of (accurate) information stating that larger pipe is better. Then again, an F150 is "better" than my Ford Ranger, and yet I haul lots of stuff just the same :) Basically, if money was no option, I would have done 6" pipe too, but there are LOTS of people using 4" pipe very successfully, myself included - and I got my pipe for free from a friend... so....

My shop stays WAY cleaner as a result of the DC setup with 4" pipe.

BUT (and this is an important BUT) air quality is not as good as it could be. I'm a hobbyist (i.e. not spending 10 hours per day in the shop), wear a respirator, run a box fan air cleaner, and my shop is detached from my home so I do not need to worry about contaminating my family with dust.

I would say that if any part of the equation doesn't hold true for you (such as your shop being attached to your home.. you're unwilling to wear a respirator... or affording the 6" pipe is not an issue for you etc.) that going with the 6" pipe is a very good choice to consider. Removing the inlet plate (just held on with 8-10 screws) and fitting a new one made of MDF (or whatever) to fit the 6" pipe makes it pretty easy going. I'll upgrade mine someday too.

[David Hostetler]

Removing the inlet plate (just held on with 8-10 screws) and fitting a new one made of MDF (or whatever) to fit the 6" pipe makes it pretty easy going. I'll upgrade mine someday too.

I am sure that this is probably not kosher by the math happy crowd. But this is a popular mod to these systems, and as long as the runs are short, and relatively straight, what results I have seen / heard about on the various forums from folks that have done this, it works fairly well. Now mind you, my shop IS attached, and I don't use a respirator unless I KNOW I am going to be performing nasty dusty tasks (using the miter saw, sanding etc...), but for my uses, 5" works well enough, for now. I think the big problem with a single 4" is you don't move enough air to get the dust top and bottom... I could be wrong. Wouldn't be the first time that's for sure!

FWIW, in the long run, I am planning on upsizing to a 6" main but keeping my 4" branches...

[Bob Riefer]

I think the big problem with a single 4" is you don't move enough air to get the dust top and bottom


I'll let you know, I'm going to be trying a 2.5" pickup on top and a 4" below on my table saw and band saw in the next couple weeks (with the idea that if it fails, I can run the top 2.5" from my shop vac [which will also be outfitted with its own thien baffle] as an easy backup if my first attempt fails). My run to my table saw is very short, so it may work, it may not. But it's worth a shot.

[David Hostetler]

I'll let you know, I'm going to be trying a 2.5" pickup on top and a 4" below on my table saw and band saw in the next couple weeks (with the idea that if it fails, I can run the top 2.5" from my shop vac [which will also be outfitted with its own thien baffle] as an easy backup if my first attempt fails). My run to my table saw is very short, so it may work, it may not. But it's worth a shot.

That works, but you are using 2 separate devices, 2 separate circuits just to power your dust collection from 1 tool. Just for testing, hook up a 4" to the second branch of your wye and run it for example to the top of your band saw. You will get MUCH better results than the 2.5" shop vac connection can do, and you are only using the single 20 amp circuit for the DC... I ran mine so the Thien separator has 5" in and out, and connected the Wye to the inlet of the separator, and then ran my branchy circuits... FWIW, what you propose is how I started out, shop vac / Thien to the tops via 2.5", HF DC / Thien to the bottoms via 4", upsizing my Thien to 5" and splitting to 2 4" branches really boosted things right along... I wish I could somehow demo the difference for you.

Not saying what you are wanting to do won't work, just saying it didn't do all that well by me, and the changes I made really improved my dust collection a LOT...

[Bob Riefer]

I'm sure you're right, and I definitely will upgrade the pipe in my system someday, but since I received free 4" pvc, I figure I might as well experiment and see what's passable and what's not :)

[Stew Hagerty]

I am sure that this is probably not kosher by the math happy crowd. But this is a popular mod to these systems, and as long as the runs are short, and relatively straight, what results I have seen / heard about on the various forums from folks that have done this, it works fairly well. Now mind you, my shop IS attached, and I don't use a respirator unless I KNOW I am going to be performing nasty dusty tasks (using the miter saw, sanding etc...), but for my uses, 5" works well enough, for now. I think the big problem with a single 4" is you don't move enough air to get the dust top and bottom... I could be wrong. Wouldn't be the first time that's for sure!

FWIW, in the long run, I am planning on upsizing to a 6" main but keeping my 4" branches...

Here is my thinking Dave; Like I said, the HF has a 5" inlet without modifications. But it also has just a 5" outlet into the filter (I replaces the bag with a Wynn filter). So do you think that upgrading beyond 5" has any real value? I would love to run 6" or even 7", but I'm not sure that it would do much.

What do you think?

[Chris Padilla]

Stew,

You don't mention if you are going with PVC or metal duct. PVC is only available in the even integer sizes (4", 6", 8"...). You may wish to price stuff out to see how you want to approach it. 5" is certainly better than 4" and 6" often works the best in most situations.

[David Hostetler]

Here is my thinking Dave; Like I said, the HF has a 5" inlet without modifications. But it also has just a 5" outlet into the filter (I replaces the bag with a Wynn filter). So do you think that upgrading beyond 5" has any real value? I would love to run 6" or even 7", but I'm not sure that it would do much.

What do you think?

That's why I went with 5", was the size between the impeller housing and the inlet ring on the dust collector itself. A lot of folks DO upsize the port on the inlet to 6" but I assume that after the impeller is the restriction back to 5"... So I chose 5" to maximize what I had available to me... And it seems to work well. Now mind you, I am not running 5" to neck down to a 4" port, I am splitting to 2 separate 4" branches, not sure about the whole surface area thing, but it does seem to work well...

[Stew Hagerty]

That's why I went with 5", was the size between the impeller housing and the inlet ring on the dust collector itself. A lot of folks DO upsize the port on the inlet to 6" but I assume that after the impeller is the restriction back to 5"... So I chose 5" to maximize what I had available to me... And it seems to work well. Now mind you, I am not running 5" to neck down to a 4" port, I am splitting to 2 separate 4" branches, not sure about the whole surface area thing, but it does seem to work well...

Thanks Dave, I think I'm going to go ahead with the 5".

[Jason Ryan]

James how did you cut the opening do you have any pictures?

I stumbled across this fantastic free online software by Harder Woods for printing cutting templates to joint two cylinders together. You can choose different size cylinders and add an offset for a side inlet (versus 0" of latteral offset which would join the two in the center).

http://www.harderwoods.com/pipe.html

I threw together a quick template for a 23" barrel and 6" pipe (I guessed .25" thick). To get a full side inlet (they call it ceiling mount in the instructions), you enter the difference of the two radius' in the "latteral offset" box. So in this case I entered 8.5".

http://www.harderwoods.com/pipetemplate.php?f=dn&units=in&paper=letter&theta=90&rmd=23&rbd=6&rbt=.25&offset=8.5&Submit=Submit

I just found it this morning and plan to try it out this weekend.

[David Hostetler]

Sorry about this short derail here....

Then again, an F150 is "better" than my Ford Ranger, and yet I haul lots of stuff just the same :)

I had to laugh my tail off at that. I presently own an '04 F-150, it replaced a 2000 Ranger. In many ways the Ranger was a better truck. All of it having to do with gas mileage and manuverability. Don't be me wrong, I love my F-150, but with the extended cab, full length box, and much bigger than stock wheels / tires, I REALLY have to think about where exactly I am going to park that behemoth...

Now back to the subject at hand...

The HF 97869 2HP DC can be fitted with a new shop built impeller cover plate (the round thing with the inlet and all the bolt holes) typically guys make them out of 1/2" MDF, but I have seen other materials. The inlet pipe can then be 6" S&D pipe. A far LESS common modification that goes along with that, is modifying the output of the impeller housing to accept 6", and then even rarer, but I have seen one on a forum somewhere, most likely Phil Thien's, is the separator ring inlet tube getting replaced with 6"...

The impeller on my DC is just a hair under 11" diameter, I guess if forced to, it could support 6" duct, but it would never be completely right. Going through my Thien separator with 5", and then out to the ducts through the wye and then to the machiens in 2 4" circuits works exceptionally well for me. Yes I had to run 2 separate duct lines, which adds up cost wise, but I have drops where I need them, and sufficient collection from where I need it from...

[David Kumm]

There are a couple of factors to consider when modifying fan inlets. The fan blades are designed-in theory- to be optimized with the inlet size. Increasing it extends the inlet diameter farther into the actual blade fin and may actually reduce the cfm pushed -pulled by the blades. The surface area of the bag and the type of filter material are often underengineered for the standard collector fittings so increasing them means you probably need to change the bag to an oversized one. The cartridge type are probably OK. If you don't actually increase the cfm moved, the chips start to move too slow in the larger pipe until they restrict the pipe back to something smaller thus increasing the chip speed. Dave

[Lynn Reid]

I have my dust collector in an enclosure on the outside wall of my shop. I have just bought a HF 2hp...I hope it will fit in the enclosure...currently I have a 1HP Grizzly. I was and am seriously disappointed in the 1hp. These mods are interesting. I do think the Y wont fit correctly in my current enclosure...Id much rather have a single out that comes through the wall and then branch from that. I am glad I ran across this thread!
I have read about and watched the Thien baffle videos. I am sort of confused...with all the dust going into the drum/bucket...why even have a dust collector? There must be something I am not thinking of. It looks like a matter of which youd rather empty...the bag or the bucket! Nonetheless...I think I am going to build one.