tables saw blade guard and dust collection, duct sizing?

[Zane Harris]

I am contemplating building a table saw blade guard with dust collection along the lines of the one made by Charlie Mastro, shown and described in The Workshop Book, pages 103 and 104. My question is, I am currently limited to using a shop vac with a 2-1/2 inch hose, but want to eventually move up to a dust collector system that has 1200 CFM @ 4", and a static pressure of 11.5".

I will probably run a 4" line to the overhead dust collection, and another 4" line underneath the saw. With that in mind, what size updraft tube would you recommend to transition from the blade guard to the dust collection (both current shop vac and future dust collector)?

TIA

Zane

[glenn bradley]

If I were building one I would go with a 4". That being said I had one that was pretty well engineered that ran on a 3" and did great. I now have a SawStop gaurd that does a surprisingly good job with a 1-1/4" or 1-1/2" hose off a T-connection at the back of the saw. Hardly optimal but, the design of the guard makes the most out of this minimal suction. I had even started to run a 2-1/2" hose before I even tried their guard as I was sure it would be inadequate . . . fooled me . I guess technology can occasionally win out over raw horsepower.

[Michael W. Clark]

Like Glenn says, it depends on the guard design. I just bought a Shark Guard and went with 3". I had seen posts where the 4" had so much flow that small pieces were lifted off the table. It could be the project piece getting lost to the DC or create a less than favorable situation if the offcut get lodged. Its also dependant on the collector you have and its capabilities.

Regarding the 1200 CFM collector, if you plan to pull this through a single 4" duct, you better bring more than 11.5" SP! I don't think 4" of SP at the inlet of the collector will be enough for the average home shop that requires this much CFM. You'll likely operate somewhere lower than 1200 CFM. Look at 6" or possibly 7" ducting to get the full flow. I'm going to run a 5" to the bottom of the cabinet on the TS and 3" at the top, should do good combined to a 6" duct at about 800 CFM. Two 4" ducts go into a 6" very well also.

[Dick Mahany]

Here are a few that I built out of 3/16 polycarbonate. Both are 4". One articulates and can be used for non-through cuts, the other pivots and releases quickly if needed on a Biesemeyer snap in splitter. Indeed 4" has a lot of flow and can pickup small off cuts, but it can easily be throttled with a blast gate.
IMGP5916.JPG

Any resemblance to a SharkGuard isn't coincidental as I used their downloadable template as an approximation. I also run 5" to the cabinet base.

[Zane Harris]

The specific collector I am looking at is the Jet DC-1200VX-CK1 Dust Collector (710702K), 2HP 1PH 230V, 2-Micron Canister Kit.

Dick, what is the overall height of your blade guard (the articulating one on the right in the picture)?

[Dick Mahany]

Dick, what is the overall height of your blade guard (the articulating one on the right in the picture)?

The dimensions are 4.625"H x 18.5"L x 4.125"W (excluding the 4" connection coupling tube). I'm running an Oneida V3000 w/ 6" ducting. I have a few more pics of the guards on my Picasa Shop Shots if it would help: https://picasaweb.google.com/dmshops...DustCollection#

[Michael W. Clark]

The specific collector I am looking at is the Jet DC-1200VX-CK1 Dust Collector (710702K), 2HP 1PH 230V, 2-Micron Canister Kit.

I have the 1100 1.5HP version with canister. I have a small shop so very short runs. With this type of collector, it is usually advised to make it portable and take to each machine. Since my runs are so short, I'm going to use some 6" metal ducting and make the machine ports 6" or split it to multiple ports on the same machine like you are considering on the TS.

The worst case is that it cannot pull enough flow to keep the duct completely clean. If it doesn't, it will balance itself out and should still provide more flow than a 4" hose or single 4" duct. I'll eventually upgrade, but wanted to go ahead and convert the connections.

[Gary Howorka]

I use a www.thesharkguard.com with a 4 inch port and an additional 4 inch drop to the saw's main body. These feed into a six inch sewer and drain PVC duct system and my ClearVue cyclone. It captures everything. Stuffing insulation in holes in the saw's main body helps seal that up to work better also.

[Rod Sheridan]

I have the factory Hammer guard on my saw which has a 50mm port. (About 2 inches).

It works great with a 50mm hose.

[Ole Anderson]

Ditto exactly what Mr. Clark said in post #3.