Duct sizing - modifying single-stage DC into 2-stage

[Steve M Grimes]

Hi all - first time posting here (I think)...

I'm planning to change my Jet 2HP single-stage collector into a 2-stage, by relocating the motor/impeller unit on the wall, ducting the 6" port down to the bag unit, which will be modified into a thein baffle with a 6" fitting. That part is pretty straightforward to me.


What I'm not sure of is how to handle the 5" port on the bag unit (which will be repurposed as the main baffle input). Given that 5" ducting & fittings are far less common than 4" and even 6", I'd like to use one of those sizes to run to my tablesaw, router table, jointer, and planer. None of those tools will be used simultaneously, so I don't need a ton of airflow, but I want the system to be fairly effective in controlling dust in my 440 sq ft garage shop.


If I adapt up to 6", will that cause any issues? I assume that it has to be better than adapting down to 4", but I don't know if creating more space causes more problems than it's worth.


Thanks in advance for any help!

[Jim Becker]

5" duct is normal and common in metal. That's an option for you for sure.

[Ron Selzer]

5" metal would be the way to go

[ChrisA Edwards]

My Jet 1.5HP is split into a 2 stage. All the ducting that feeds it is 5".

I just extended this as I'm setting up a CNC machine on the other side of my garage.

From my 5" metal drops, I go down to a Wye that has a 2.5" and 4" blast gate. From there I go to my tools with 15' of 4" flex or 20" of 2.5".

I use this setup with my Sawstop, Hammer A3-31 J/P, Hammer F3 Shaper, Drum Sander and many other tools.

The Jet DC is still wired 120V and is triggered off iVac switches from either the 110V or 230V tools.

To see the below images, you should become a Sawmillcreek contributor, ($6 per year gets you a lot of great information)

[mike stenson]

This is very useful for me, thanks for posting. I have the 2hp jet, but really only use a planer and a bandsaw. Very occasionally the table saw. This would clear up a lot of floor space for me, especially since I can vent outside.

[Carl Beckett]

Chris, that is nicely done and I recall from other posts/pics you have a pretty clean shop. Can you comment on the effectiveness of your setup? Which tools does it struggle the most with?

[Kevin Jenness]

Minimizing direction changes, using large radius (1.5 x diameter) sweeps and running rigid 5" duct as far as possible before switching to flex hose will help with efficiency. If you are eliminating filtration that should offset any additional drag from the Fein baffle.

[ChrisA Edwards]

Chris, that is nicely done and I recall from other posts/pics you have a pretty clean shop. Can you comment on the effectiveness of your setup? Which tools does it struggle the most with?

The biggest issue is chip collection from the A3-31 of my ShopFox W1812 Moulder. Not so much from suction, but clogging at the chute from the bottom of the Super Dust Deputy XL into the 55 gallon drum.

A the drum fills, in drops the clippings into a perfect cone. As this cone gets close to the top and close to the bottom of the chute, it has a tendency to clog the chute. This only happens with clippings and so I monitor the chute, by back lighting it with a work light, when planing wide boards. When it clogs, I walk over and shake the 55 gallon drum and level out the clippings inside the drum.

If I miss this, real bad, the SDD clogs and the chips end up in the plastic bag below the filter.

This video shows this light tip, since making the video, I've swapped out the plastic 55 gallon drum for a metal drum. Although a bit heavier, the metal drum has parallel side whereas the plastic drum tapers at the top. I collect the clippings into oversize 55 gallon drum bags, so the taper, on the top of the plastic drum, made it a little difficult to get a full bag out. Not the issue with the metal drum ($10, plus a bit of rattle can red).

[ChrisA Edwards]

And just a follow on

[Christopher Charles]

Hi Steve,

I recently retro-ed my set up similar to (and inspired) by Chris' system. I was able to find 5" metal pipe for reasonable price from my local heating/AC shop. Was worth it to gain some floor space and have everything 'hard-piped' rather than constantly switching hoses.

I have a cartridge filter on order and will post an update once it is installed. Currently, I'm running with just one of the cloth bags and it generates enough back pressure that the system is underperforming.

Best,
Chris

[Carl Beckett]

Hi all - first time posting here (I think)...

Member since 2007. First post yesterday. That is a lot of lurking! Glad to see you active.

[Keegan Shields]

Chris,

I have a similar setup with 6" flex hose dropping down from my DD XL to a 55 gal metal drum.

I've found that ensuring the 6" hose is straight and the drum is positioned directly under the exit hole of the DD XL was required to stop clogs like this.

Might help here.

dc.jpg

For the OP - I bought the 5" snap lock pipe from HD. Its thinner (22 ga) than the HVAC store stuff but has worked fine. No collaspsing issues (unless I step on it )

[Bruce Wrenn]

You can put the Thien Baffle into the ring on your DC, saving a lot of work

[Jim Becker]

For the OP - I bought the 5" snap lock pipe from HD. Its thinner (22 ga) than the HVAC store stuff but has worked fine. No collaspsing issues (unless I step on it )

That would be 30 gage HVAC pipe. 22 gage would be uber-thick and heavy!

[Keegan Shields]

Oh yeah, good call out. HD pipe is only 30 ga and the nicer HVAC supply stuff is 26 ga.