4" Port Shark Guard - DC from 2 directions, can this be too much of a good thing?

[Don Buck]

I’m installing my PVC DC collection (3 hp single stage/dual bag) in my home shop and am pondering about the best collection option for my Dewalt 746 tablesaw. I have a 4" port Shark Guard on order and will have a 6" pipe dropping from above reduced to 4" to accept the 4" flex pipe. I am wondering what to do with the 2.5" port under the saw. To date this port worked fairly well as long as the OEM blade guard is used. I am considering hooking up a 2.5" flex hose from another DC outlet and pull dust from above and below.

With this improved upper dust collection is it still a good idea to plumb in a 2.5" line to the lower existing DC outlet on the saw? It seems like to some degree that the 2 outlets will be working against each other. I assume that the guard's rear opening will be more than sufficient to allow enough air to satisify both outlets. Opinions and/or actual experience - Is the 2 port collection the way to go or is it going to possibly reduce the effectiveness of the dust collection?

[Jerome Hanby]

I'm still waiting for my 4" port Sharkguard to arrive (it's in the PO system). I'm installing a Y connector coming out of my shop built under saw dust collection to run up to the Shark Guard. Guess I'll see how well it works uing one run from the dust collector for both sources. I've got a blast gate to cutoff the Sharkguard for times when it won't be attached (non through cuts), wonder if it would be a good idea to add another to cut off the under saw collection?

[Rod Sheridan]

The standard approach is above and below the blade dust extraction.

I've used that approach for years and it works great.

That said, I'd change the cabinet port to 4" from 2.5".............................Regards, Rod.

[Prashun Patel]

I used a Sharkguard 4" with a 4" port from the cabinet too. The DC was better on that hybrid saw than it is with my current Sawstop with it's fangled blade guard.

I agree with Ron: make the cabinet hole 4".

[phil harold]

reduce your 6" to two 4"
plumb one above the saw and one below even if you have to use an adapter (or you could enclose your the base of your saw)
6" diameter = 113 square inches of area
4" diameter = 50 square inches of area

[Stan Krupowies]

reduce your 6" to two 4"
plumb one above the saw and one below even if you have to use an adapter (or you could enclose your the base of your saw)
6" diameter = 113 square inches of area
4" diameter = 50 square inches of area

Not sure about those numbers. Area of a circle = pi x r^2

6" diameter = 3" radius -- 3.14 x 3 x 3 = 28.26"
4" diameter = 2" radius -- 3.14 x 2 x 2 = 12.56"

Oh, I see it - you did pi x d^2

[phil harold]

Not sure about those numbers. Area of a circle = pi x r^2

6" diameter = 3" radius -- 3.14 x 3 x 3 = 28.26"
4" diameter = 2" radius -- 3.14 x 2 x 2 = 12.56"

Oh, I see it - you did pi x d^2

My Bad!!

but still the the same point you have plenty of sq inches out of a 6" pipe to pull two 4" pipes (this does not include drag)

[David Hostetler]

I have a HF 2HP DC with 5" line split to 2 4" lines. My table saw has a shop made belly pan with a 4" port, and a factory blade shroud (under table) with a 2.5" port. I split one 4" line to the 2 ports, use a zero clearance throat plate, AND a Shark Guard with the 4" port on the top side. Even though I have far more surface area open at the machine than I have available at the DC, It works great. You with your 3HP rig and 6" pipe should have no trouble at all. Just be careful, the 4" port wants to suck up small cutoffs if you let it. Partially close off the blast gate to reduce flow if you have that problem.

[Matthew Sherman]

Not to hi-jack the thread, but how do you like that shark guard. I also have the Dewalt 746 and have thought about getting one of those.

[Chris Atzinger]

+1 regarding the DW 746 with a shark guard. I inherited one without the blade guard and was planning to replace it with the shark guard.

Thanks!
Chris

[Don Buck]

My 4" port Shark Guard for my Dewalt 746 arrived last week and had to delay set up as my factory guard had a wing nut instead of the std nut on the outer plate of the "splitter". Found the metric nut at a hardware store on Monday and set it up and have ripped and chopped a few boards for a test run. My dust collection is still a work in process but I reduced the 6" line overhead to 4" for the Shark Guard and for the trial hooked up my Shopsmith DC (2 1/2" hose) to the Dewalt belly pan. Not a fleck of dust on the table with the trial cuts. I had ripped about 1200 linear feet of poplar the previous weekend with the factory guard and the Shopsmith 2 1/2" DC - I could see a couple of inches of poplar dust in the DC bag but after all the ripping my arms and shirt were covered with poplar dust from dust that shot out of the factory guard. I wish I had this years ago.
FYI - I did email Lee at Shark Guard about the height gap between the rear of Shark Guard and the table before I did my test run as I was expecting the Shark Guard to sit fairly flush on the board and I had about 2" between the table and the rear of the guard (or about 1" gap with a full 4/4 board on the table). Lee promptly emailed me back and said the gap is normal and with the shorter of the 2 guard brackets I could process up to 2" lumber without switching to the taller bracket. He said if I needed a shorter bracket he could fab one but he didn't think I would have any problems with the "gap" as it serve as allow the inbound air flow in from the rear. It works just fine.