Tablesaw Dust Collection
Table saws pose a pesky dust collection problem. Here's a handful of tips and suggestions. December 30, 2005
Question
Does anyone have any suggestions on how to hook a tablesaw up to dust collection? We've got a pipe hooked into the cabinet at the floor of our Delta Uni-saw (right tilt). We don’t want to use anything that hangs over the blade. Sealing around the motor and still being able to tilt and raise/lower it seems to be the real problem.
Forum Responses
(Cabinetmaking Forum)
From contributor A:
Doesn't your cabinet saw have an outlet in the cabinet to hook up a dust collection hose?
From contributor B:
Get some silicone and seal between table and cabinet, and seal the slanted bottom in cabinet. Take a piece of rubber 12'' x 12'' and cut it down the middle matching the slot at the tilt hand wheel, but not all the way to the ends. Pull the tilt hand wheel off and put this piece of rubber on to help seal the air gap. Any little thing that I did to make the air inlet at the blade slot helped cut down on excess dust.
From contributor C:
I have worked in shops that have the biggest cyclones you ever saw for dust collection. Even in those shops, dust collected. 10" saws offer the convenience of not having to shovel the saw dust from the cabinet. In all situations I have seen, you must open the saw cabinet hatch periodically and push the dust by hand towards the collection hose to keep the saw cabinet empty. One thing that I have seen is having one of those guards suspended on an overhead system, and if that has a dust collection hose attached, it does a good job of catching the dust that flies off the top of the saw blade into the sawyers face and lungs.
From contributor D:
What size pipe are you running to the Unisaw?
From contributor E:
Get a 2-1/2 gallon plastic bucket, non-tapered. Put an end on the top, then cut a 12" wide x 14" hole in one end. Cut a 4" hole in the bottom at the other end for a 4" DC connection. Run a flex line from this to the DC outlet of the cabinet. Other slots etc. will need to be cut in the bucket to attach (or to straddle part of motor, etc.), but in the end the bucket will sort hang from the bottom of the blade with duct tape. The spinning blade forces the dust down and to the rear, and the DC does the rest.
From contributor C:
To contributor E: How do you put an end on the top of a 2.5 gallon bucket? Also, what is a 12" x 14" hole? And how do you put that on the end of the end on the top?
From the original questioner:
The dust port at the bottom has a 4 inch pipe hooked to it, branched off of a 6 inch. We've got a killer system with plenty of suction. It's just getting it sealed off so the suction pulls from the right place. Is there anything you can do that is a real fix that doesn't require duct tape or an overhead arm something-or-other hanging in your face? I was thinking of maybe building a sealed box around the saw itself but what about the issue of overheating?
From contributor F:
I thought plastic was a no-no in any part of a dust collection system due to the chance of a static shock causing an explosion. A shroud around the blade however is an excellent idea as evidenced by industrial level machines of modern design such as European panel saws. They have a removable (lift-off) shroud around the blade which gives much better pick-up than older designs. As to blade height, I frequently run 1 inch or more above the stock depending on such factors as burning and cut quality. Dust pickup is secondary to these concerns for me.
From contributor C:
To the original questioner: The point I tried to make is that the dust from your saw that really offends you (and pollutes the shop air quality) is what comes straight off the top of the blade and straight into your face. The best collection device in the world for the inside of the saw cabinet won’t pull that dust down through the throat plate insert slot.
To contributor E: I am serious. I agree with contributor F that a shroud type arrangement would be more effective in the saw cabinet. I just wish you could give a more cohesive explanation.
From contributor G:
I think Delta and other makers of these saws need to put some research and development into their dust collection design. Every time I use one these there is always a pile of dust on the floor. I have 2 saws in my shop, an old Martin T-17 and a Wadkin. Both saws have built-in shrouds below the throat plate that surrounds the lower half of the blade with the dust chute located on the bottom, in the optimal location to maximize saw dust collection. Maybe Delta owners can device something similar. With a zero clearance plate there is hardly any dust. And all I have is a 2 hp collector!
From contributor D:
To the original questioner: As I suspected, you are using the 4” dust port supplied with the machine. This is totally wrong. If you read a dust collection manual it will recommend 5" at the very least to pull the chips coming off a dado set. Hogging with a 3/4" dado set produces a lot of chips. The table saw is not your ordinary tool from which you pull dust. With most every other machine you are pulling from a concentrated source. The table saw is fairly large box. You need volume of suction, not pressure. The dust that bothers us so much is very fine and light and therefore doesn't need much velocity or pressure. It needs pure CFM.
The other problem is the box is about 20'+ at the point of suction. Instead of jamming a round pipe in there you need a rectangular plenum. I run 6" pipe into a HVAC 6" to 1 1/2" x 12" rectangular 90 degree elbow. I simply screwed a piece of plywood across the bottom 10" of the saw box; then screwed the plenum to it. The pipe runs under the front of the saw past the fence and up the wall. This works very well because you have lots of CFM and it is evenly distributed across the entire face of the box with no dead spots. You want the bottom of the plenum hole in line with the bottom of the ramp.
From contributor E:
The bucket is a shroud. As for the 12"w x 14"l cut-out, it's on the side of bucket (which becomes the top when installed). The 4" hole is in the bottom end (which is the side when installed). I know it's clear as mud, and exactly how it installs I don't remember. I just remember reading a shop tip in some magazine some time ago. The drawing was a line rendering, so whether this guy actually built and used it is questionable.
From contributor H:
I run both a Biesse guard with 3" hose and a 4" port on the cabinet base. Before I had the blade guard, I drilled a hole in my zero clearance insert just forward and to the left of the blade slot. Then round over both sides of the hole to reduce turbulence a bit. This works pretty well for getting dust from edge rippings. But you definitely need high static pressure, not just high air flow in your system. I recently upgraded to a 19" impeller blower that can pull 20" static pressure. My saw cabinet is very clean now - nothing collecting in the base. My saw (General 350) has a shroud cast into the trunion, but I haven't hooked anything up to it, since it would likely clog with thin strips that get sucked down into the insert. Then again, I haven't had a problem with these strips with the new blower - they just thump right through.
The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).
Comment from contributor L:
When pulling dust from the base of a table saw, the chips need to be directed to the outlet collar with a hopper built inside the saw base. Make sure to slope three sides toward the outlet - steep sides work best. The hopper can be from light plywood, sheet metal or heavy paper.
Comment from contributor W:
I built a dust collection cabinet for my Delta contractors saw out of plywood. I used thin sheet metal to form a slope/funnel to a 4" hose connector. I also used spray foam to seal the gaps under the cast iron table top. Lastly, I used sheet magnet, (a 3" x 6" magnetic calendar from the refrigerator) to seal the tilt slot at the front.
