perforating ZCI to improve dust collection?

[Gil Liu]

Hi All,

Wondering what opinion you had about punching several small holes in my table saw's zero-clearance insert to help with dust collection. Ever since using ZCI's, I've noticed more dust coming from above the plate. I do have an overhead guard with dust collection (Sharkguard), but don't use it all the time. I have a 3hp dust collector that is a short run from the saw, so I think there's good suction, but not where it's needed without the overhead guard. Also, I'm working in a basement, so I need optimized collecting.

Thanks,
Gil

[James Phillips]

I do not think this will help. The blade pulls the dust under the table during the cutting motion. The dust above the table comes from the portion of the blade moving up at the back of the saw.

You might get a little improvement by widening the ZCI blade slot, but then it is not a ZCI

Cheers

[frank shic]

gil, after spending all that money and then waiting all that time to receive the sharkguard, why aren't you using it? i purchased one last year and feel pretty comfortable making cuts without wearing a dust mask. i have found that the suction on the thing is so strong that it will actually suck up home made blade inserts!

[Aaron Montgomery]

I would think that you could widen the back half of the ZCI (center of the blade back) without losing the benefits of the ZCI. If you make your own ZCI, then your not out anything to experiment a little.

[Jason Beam]

How will the air get into your perforated or widened holes when the wood is covering them up?

[Gil Liu]

Thanks all for your quick and thoughtful replies. Frank, I hate to admit that I haven't gotten it connected to my dust collection -- still debating between ceiling versus saw mounting. Jason, your reply was an 'ah-hah' moment for me -- I have no idea how the air would flow through the wood being cut. I'll get crackin' on the Sharkguard hookup.

Gil

[Howard Acheson]

Jason, ya beat me to it.

That said, another thing to keep in mind about dust collection is that what you want to optimize is the air flow, not the suction. You need to have about the same number of square inches of air inlet as have for exhaust. For example, a 4" pipe has about 12 sq. inches so a saw needs about the same number of square inches of air inlet. In addition to air flow, it is important to consider flow direction. You want your primary pick up to be at the point where the blade is throwing the sawdust. Sawdust is moving at over 100 mph when ejected from the blade and there is no way that the DC air flow is going to change that direction until the dust slows down.

[glenn bradley]

I've seen this done but have not tried it. My throat plate is generally covered when I'm cutting. I do use my blast gates to throttle the lower cabinet hose and focus more draw on the overarm when it is in use. If I had enough suction to keep the top of my TS spotless it would probably suck up my pencil.

[Jason Beam]

Soon as I locate me one of them there fancy circular tuit jobbies, I hope to come up with a way to adapt a shroud around my blade under the table. Like many of the hybrid saws do it. This, to me would beat the heck out of any other enclosure, i'm thinking. Maybe ... if I ever locate one.

[Andrew Catron]

might be a little bit of work, but how about a grid of kerf cuts spaced about an inch or so apart with holes drilled at the intersections? that way there is a place for the dust to go when your wood is on top of the zci and you wouldn't lose the benefits? the only drawback (could be dangerous) is with small pieces you may get caught up on the kerf cut....

[frank shic]

gil, mount that dust collection hose from the ceiling! i've got mine currently hooked up to the sharkguard and then suspended over the saw by a couple of ropes and the annoying thing is that the weight of the dust collection hose will tend to drag the guard off to the right causing the bladeguard to deflect and jam the cut. one of these days i'm going get an armload of hose and hang it it so that there's a vertical drop from the ceiling.

[Chuck Lenz]

What type of tablesaw are you useing ? Bench ? Contractor ? Hybrid ? Cabinet ?

[Gil Liu]

Hey All,

I'll say what's been expressed many times before -- I really appreciate the kind atmosphere and abundant great advice of the Creek.

Chuck: I am the proud owner of a right tilt Unisaw with Bies fence & Benchdog routerplate

Frank: I'm letting 'perfect' be the enemy of 'good'. I asked Jeff Makiel to email me the plans to his completely amazing shop-made overarm guard (for anyone interested, the old threads are easily found by searching 'overarm guard') and am leaning towards constructing a similar mount to connect to the Sharkguard. I should quit procrastinating and just get the thing attached to the ceiling and be done with it, but I often have to move my saw because I'm in a small space.

Gil

[Brian Kent]

Gil,

At the risk of blowing my one potential invention that would make me rich, I want to try what you are describing, with holes on the left front side of the ZCI, pointing towards the front of the blade.

My biggest sawdust mess is when I am trimming the edge of a board on the table saw, with a cut narrower than the blade kerf. As I even out the board, the blade throws the sawdust to the front left corner of the table. I am thinking the angled holes could just divert the dust.

Then again, the invention might not work and I would still have to work or a living.

[Bruce Wrenn]

Soon as I locate me one of them there fancy circular tuit jobbies, I hope to come up with a way to adapt a shroud around my blade under the table. Like many of the hybrid saws do it. This, to me would beat the heck out of any other enclosure, i'm thinking. Maybe ... if I ever locate one.Lowes stocks a 4" X10" register boot, with a 4" outlet. On a contractor's saw, it would be easy to put it up through bottom so as to semi enclose blade. It would have to be removable for tilting the blade though.

[Jason Beam]

That's a good start, Bruce. If my radially uniform tuit ever comes in, that's exactly where I plan to begin. I'm hoping to come up with a way to mount something that'll tilt and raise/lower with the blade. Tilt, at least. I may not need to raise/lower with it.

[Noah Katz]

I don't see how any kind of holes you put in the ZCI could allow enough airflow tio be effective.

[Alan Greene]

Gil,
Here is how I set up my Shark Guard to work with my DC. The DC connects to a 4" HVAC duct from the Borg that goes under my out feed table to the saw connection and then continues on and up the wall and across the ceiling where it drops down with flex hose. This saves me a lot of time and it picks up the dust pretty well. I can control the flow with a blast gate at the end of the drop down hose. It is not ideal but will work until I get the Cyclone. I can also use it for the router table extension. I hook it to the Air cleaner to get it out of the way when I am using the my sled.

[glenn bradley]

What type of tablesaw are you useing ? Bench ? Contractor ? Hybrid ? Cabinet ?

Hybrid here.