[kindanewbie]

I have a 5 gallon bucket beneath my table saw as im assuming is pretty standard. But for whatever doesnt fall down, I have a big window fan that I use. Its a 2350 cfm so moves a lot of air.When I cut,it generally clears the garage out in 7 or 8 seconds. As silly as it sounds, Ive gotten in the habit of holding my breath for a cut, then stepping back for a few seconds before continuing. But, I generally dont cut a whole lot at once. My current projects will require a bit more focus on the table saw so its time for a better solution.

I was going to do the cyclone collection but then I figured I have the big powerful fan, maybe harness that better.

The fan is 9 feet from my blade. As you can see in the pics below, I set up a real rough proof of concept. I framed the fan with some old Pergo, covered the face with cardboard, made 5" tubes from left over aluminum from when I sided thr house, and tie-wrapped and duct taped it all together.

I rested the end of the tube next to the saw and turned the fan on. It seemed to be a good high volume, low pressure suction, easily felt, and sucked a piece of cardboard up to it. When I drop sawdust near it, it sucks it all up.

But when I used the saw, I still had small particles floating in the air. Better than usual. BUT, even though there is less particles in the air, there is still some (a little more than I expected but maybe my expectations were too high) and now no fan to clear it out.

To be fair, this is a real rough test and there is plenty of leakage around the frame and cardboard and the window is only open 80% as its old and sticks. But to offset that, if I made this permanent, I would run it to along the rafter so it would be a longer run with three 90s.

I think 2350cfm is pretty good if I can harness it properly.

How much of the dust do you expect a collection system to get?
Is there a better place to put the hose? Front of the blade seemed better. I guess hanging from above, a few inches above and toward the front of the blade?

Any thoughts or expectations?

 

[Steve Neul]

Be sure to blow the motor on the fan out often. The fan isn't designed to move dust.

 

[GlennL]

Well it all boils down to how important it is to you, and how much you want to spend. The house fan is designed to move clean air, and saw dust is going to be hard on the motor. As was mentioned, you'll need to take an air compress to it regularly.

The dust collection will be most efficient if you can "surround" the blade and cabinet. With a hose just sitting next to the blade, it isn't going to capture much. The force created by the spinning blade will throw most to the saw dust around, and little will be captured.

I have a 2HP Grizzly dust collector, with a trash can cyclone. I have a hood over the saw blade, and another on the side of the cabinet, as the saw is enclosed. This has worked extremely well, and I would guess that 90%+ of the saw dust is captured.

This past weekend I decided to incorporate the "Blade" dust collection portion with the saw. Prior to that I had piping along the ceiling, and a hose down to the blade hood. Problem was...the saw pretty much has to be in one spot. With the new design, I have a lot more flexibility as to where I can place the saw.

There are a number of companies that make units that cost north of $500. I had some metal, and extra hose hanging around, so I decide to upgrade what I had. It could have been made out of wood as well, you just need a support for the hose. I have some 1/4' Lexan and will probably design a new hood for the blade.

 

[kindanewbie]

Very nice. Yes, I planned on collecting at the blade and the cabinet. I have this model Ryobi

it is built into the table and sits on top of platform with a 5 gallon bucket beneath it. So the bucket gets a lot of it. I need to capture on top at the blade (like your hood) and then enclose the base below the platform so that I can get whatever comes out of the sides and back of the blue base. I figure an offshoot 2 inch hose or so should handle the dust below the cutting platform and the bigger 5 or 6 inch at the blade. But placement is the issue.
In your pics, I think this might be a silly question, but the blade is totally covered by the hood, I guess it is adjustable by so that you just lift it to be 2 or 3 inches above the blade when cutting? Is the aluminum hose strong enough to keep its position if you pull it up and down a bit?

 

[DrRobert]

Exhaust fan is good, people In climate cppo trolled shops will loose air. An overhead air filtration unit is advisable.

Instead of holding your breath how about a dust mask?

All the dust danger is above the tabke, but keep in mind overarm collection on a table saw is limited. Very good for sheet goods, but not much for narrow rips, using miter gauge, sled, if you prefer to use a push shoe rather than sticks (yes) or when using some fixtures off the fence.

 

[GlennL]

Very nice. Yes, I planned on collecting at the blade and the cabinet. I have this model Ryobi View attachment 447154
it is built into the table and sits on top of platform with a 5 gallon bucket beneath it. So the bucket gets a lot of it. I need to capture on top at the blade (like your hood) and then enclose the base below the platform so that I can get whatever comes out of the sides and back of the blue base. I figure an offshoot 2 inch hose or so should handle the dust below the cutting platform and the bigger 5 or 6 inch at the blade. But placement is the issue.
In your pics, I think this might be a silly question, but the blade is totally covered by the hood, I guess it is adjustable by so that you just lift it to be 2 or 3 inches above the blade when cutting? Is the aluminum hose strong enough to keep its position if you pull it up and down a bit?

The hood pivots, and has a 3" height clearance over the table when cutting stock. Now that I have the new "arm" assembly built, I plan to make a new hood assembly that will be supported by the arm. Currently the hood "floats" and is supported on the splitter. I just position the piece of wood I'm cutting so the front edge is under the hood, and in front of the saw blade. The hood just rides/floats on top of the piece being cut.

There is a slot cut in the hood to allow it to move up and down...

Right around 3" height clearance...

 

[woodnthings]

How much of the dust do you expect a collection system to get?
Is there a better place to put the hose? Front of the blade seemed better. I guess hanging from above, a few inches above and toward the front of the blade?

I made mi own over the blade dust collector with 2" PVC and a vertical stand down to the mobile base:

Very nice. Yes, I planned on collecting at the blade and the cabinet. I have this model Ryobi
it is built into the table and sits on top of platform with a 5 gallon bucket beneath it. So the bucket gets a lot of it. I need to capture on top at the blade (like your hood) and then enclose the base below the platform so that I can get whatever comes out of the sides and back of the blue base. I figure an offshoot 2 inch hose or so should handle the dust below the cutting platform and the bigger 5 or 6 inch at the blade. But placement is the issue.

There are two kinds of dust, very fine from sanding and sawdust. Then there are larger chips and shavings from jointers and planers.
The most hazardous is the very fine dust which can get airborne and you'll end up breathing it in unless you wear a mask.
Your "exhaust fan" will only change the air in the shop, it won't "collect" any dust, unless you put a furnace filter in front of the fan.
The dust collection shroud on the your saw is a giant step in containing the sawdust and use a shop vac on that port!
You can put a Dust Deputy (Oneida) or Duststop (Home Depot) in front of the hose to the shop vac which should catch most of the finer dust.

Most floor style dust collection units ( Harbor Freight, Grizzly, Delta, etc) have either bags or cannister filters to prevent the dust from entering the shop. The larger units with larger hoses, work best for collecting the chips and shavings from jointers, planers, and from drum sanders and table saws without the dust shroud.

Once the larger particles drop down into the base of the table saw they will not get picked up by the floor style DC units unless it's very close to the 4" dust port. If you grab a handful of sawdust and throw it up in the air, you'll see the larger particles drop down immediately but the finer ones float around in the air for a long time. This is the issue with any shop dust collection system.
So, you'll need the following:
1. Overhead air filtration with filters to scrub the fine dust from the shop air you breathe, or an exhaust fan to change the air with fresh air incoming.
2. High velocity air movement from shop vacs on al the 2 1/2" ports on miter saws, bandsaws, hand held sanders, any place dust is generated with a small port.
3. Floor style DC units of 1.5 HP to 3 HP ( Harbor Freight, others) with high volume air movement (CFMs) for all the larger stationary machines like jointer. table saw etc.

It just not as simple and as easy as you may have been led to think......

 

[deltap]

A prop fan is your worst choice for dust collection. Ok if you just want to blow the air out through the side wall. Air delivery drops rapidly when ductwork is added. Best choice would look like a silo blower with straight blades that won't clog up. As has been said already the motor should not be in the dirty air stream.

 

[kindanewbie]

Exhaust fan is good, people In climate cppo trolled shops will loose air. An overhead air filtration unit is advisable.
Instead of holding your breath how about a dust mask?
All the dust danger is above the tabke, but keep in mind overarm collection on a table saw is limited. Very good for sheet goods, but not much for narrow rips, using miter gauge, sled, if you prefer to use a push shoe rather than sticks (yes) or when using some fixtures off the fence.

Not concerned about air loss, thats not an issue for me. As for the mask, Im usually just cutting a couple of pieces, rarely long sessions. Poor excuse really.
Im not sure what you are getting at with the explanation of the dust below that table? Is it that, regardless of dust collection method... use a mask?

 

[kindanewbie]

I plan on using the shopvac on all the 2 inch connectors (jointer, miter saw, electric hand planer) so Im good there.
Its the small airborne stuff I want to get rid of. The window fan cleans out the entire garage in about 5-7 seconds. Cut a piece of wood, and the air is filled with small particles, turn the fan on and almost immediately its all gone. And thats without concentrating it in a single spot (throught ductwork to a hood) I dont see how it could possible not clear the small particles so long as it is placed in the right location, say 3 inches above the blade. It doesnt collect it, just blows it out the window. The vast majority of the dust still falls into the 5 gallon bucket below the saw.
No way I can spend multiple hundreds right now. And honestly the window fan clears the garage in 5-7 seconds even as is (without focusing the suction through a duct to a hood) so I have no doubt it is powerful enough to get the job done. Im just not sure about placement. I like the hood and the pvc above the blade. something to think about.

 

[kindanewbie]

The hood pivots, and has a 3" height clearance over the table when cutting stock. Now that I have the new "arm" assembly built, I plan to make a new hood assembly that will be supported by the arm. Currently the hood "floats" and is supported on the splitter.

The splitter is the anti-kickback piece?

 

[GlennL]

The splitter is the anti-kickback piece?

Yes. Today's new saws have a riving knife, which is much better!!!!
I really like that feature on my portable DeWALT saw!

 

[woodnthings]

I plan on using the shopvac on all the 2 inch connectors (jointer, miter saw, electric hand planer) so Im good there.
Its the small airborne stuff I want to get rid of. The window fan cleans out the entire garage in about 5-7 seconds. Cut a piece of wood, and the air is filled with small particles, turn the fan on and almost immediately its all gone. And thats without concentrating it in a single spot (throught ductwork to a hood) I dont see how it could possible not clear the small particles so long as it is placed in the right location, say 3 inches above the blade. It doesnt collect it, just blows it out the window. The vast majority of the dust still falls into the 5 gallon bucket below the saw.
No way I can spend multiple hundreds right now. And honestly the window fan clears the garage in 5-7 seconds even as is (without focusing the suction through a duct to a hood) so I have no doubt it is powerful enough to get the job done. Im just not sure about placement. I like the hood and the pvc above the blade. something to think about.

A fan is just not designed to deal with dust. The overhear air filtration units have squirrel cage blowers, not propeller type fans and they have multiple filters ahead of the blower to clean the air of dust before it gets clogged up on the fins of the blower.
Your best location for the fan to change out the air is in an open window blowing outwards. Across the room/shop another open window will allow clean air to be drawn in across the room. The fan will create a negative pressure in the room so fresh air will flow right in.
Only the finest airborne particles will be drawn out of the shop by the fan, no actual "dust" because it's too heavy and not airborne.