Table Saw Dust Collection

For the new shop I am building, I am planning to dedicate a fair bit of effort and $$ to get dust collection to all of my power tools. I had envisioned minimal dust escaping into the shop space.

I recently moved my table saw out of storage into the shop I have under construction. It has been really helpful having the saw for installing exterior trim.

Yesterday I had to rip some long lengths of Miratec (basically man-made trim for exterior use) which created a lot of airborne dust. I wore a respirator but the amount of dust generated really got me thinking. I realize now that while I can probably come close to my goal with most of my tools, the table saw is going to be a challenge.

The saw I have is a 20 year-old Craftsman contractors saw without any modifications. I am planning to upgrade to a cabinet style saw for the new shop.

I have read about the Saw Stop overarm collection being so-so. I have read some of the aftermarket overarm collectors work OK - opinions?

For cutting materials that generate a lot of lightweight airborne dust with a modern cabinet saw equipped with dust collection above and below the blade can airborne dust be eliminated or reduced to negligible amounts? Is this an unrealistic expectation?

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Originally Posted by Kris Cook

For the new shop I am building, I am planning to dedicate a fair bit of effort and $$ to get dust collection to all of my power tools. I had envisioned minimal dust escaping into the shop space.

I recently moved my table saw out of storage into the shop I have under construction. It has been really helpful having the saw for installing exterior trim.

Yesterday I had to rip some long lengths of Miratec (basically man-made trim for exterior use) which created a lot of airborne dust. I wore a respirator but the amount of dust generated really got me thinking. I realize now that while I can probably come close to my goal with most of my tools, the table saw is going to be a challenge.

The saw I have is a 20 year-old Craftsman contractors saw without any modifications. I am planning to upgrade to a cabinet style saw for the new shop.

I have read about the Saw Stop overarm collection being so-so. I have read some of the aftermarket overarm collectors work OK - opinions?

For cutting materials that generate a lot of lightweight airborne dust with a modern cabinet saw equipped with dust collection above and below the blade can airborne dust be eliminated or reduced to negligible amounts? Is this an unrealistic expectation?

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It is possible to greatly reduce the fine dust although it took me awhile before I got something I was happy with. I used 4" dust collection connections above the blade and a 5" connection from the cabinet of my Unisaw all coupled to a 3HP cyclone. I wound up building my own blade guards based on the SharkGuard design out of polycarbonate and they did an excellent job in reducing dust although not perfect. I don't have experience with any of the commercially available solutions so I can't comment on them. High volume air flow was essential.

Attachment 411424

On the wide guard, I actually had to throttle the 4" blast gate down a little as the guard would vacuum down to the table.
Attachment 411425

Dick - thank you for the input. That is nice work.

While collecting from the cabinet and around the blade from below is certainly important (and will be easier with a cabinet saw or slider than with the contractors' style saw), over blade collection is essential for maximum performance. Ideally, that collection needs to be "disconnected" from the saw, too, so that you can continue to use it with almost every cut type you might want to perform. Guards/hoods that physically attach to the riving knife or splitter unfortunately have to be removed for non-through cuts and as a result, they rarely get used by many folks. What Dick shows above is one good example of a solution that works for most cuts and because of the hood size and connection to the extractor, it will likely perform well. There is a LOT of material that comes off the top of the blade as you have clearly discovered!

I used the Shark Guard on my Grizzly and I use the Sawstop now. They both attach to the riving knife, so what Jim says above definitely applies. Both do pretty well on cuts where the material extends past the edge of the guard on both sides but are not great on little trim cuts.

My Shark Guard had 4" hose down to the guard, but the Sawstop one I have has only a 2"(ish?) hose, and I think it suffers for that. Something's better than nothing though. I may yet order the piece that would let the SG work with my new saw. Good luck!

Jim

On my old Unisaw I added a 4" DC port at the bottom of the cabinet, built a ventilated motor enclosure as there was no motor cover when I got the saw and built 1/4" masonite ramps in the bottom of the saw to help the dust along. It worked well. The problem, as noted was the dust coming off the blade. I no longer have that saw but had I kept it I was planning on adding and air line to it to see if I could "blow" the dust out of the gullets of the blade making it possible for the under table DC to pick it up and keep most of it it from being thrown back at you. That could improve the function of the above table collection. One question I had was how much of the blade dust is instantaneous in coming off the blade as it cuts vs being carried in the gullets of the blade as it spins. Does the blade load up and then expend it? If so do you think an air nozzle or two could help get the accumulated dust off the blade below the table? i doubt that a side load of air could create oscillation in the blade...right? Or perhaps a nozzle on either side. I was looking forward to running that test, but my daughter bought me the SS PCS so the Unisaw went to a friend. What do you think?

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Originally Posted by Jack Frederick

On my old Unisaw I added a 4" DC port at the bottom of the cabinet, built a ventilated motor enclosure as there was no motor cover when I got the saw and built 1/4" masonite ramps in the bottom of the saw to help the dust along. It worked well. The problem, as noted was the dust coming off the blade. I no longer have that saw but had I kept it I was planning on adding and air line to it to see if I could "blow" the dust out of the gullets of the blade making it possible for the under table DC to pick it up and keep most of it it from being thrown back at you. That could improve the function of the above table collection. One question I had was how much of the blade dust is instantaneous in coming off the blade as it cuts vs being carried in the gullets of the blade as it spins. Does the blade load up and then expend it? If so do you think an air nozzle or two could help get the accumulated dust off the blade below the table? i doubt that a side load of air could create oscillation in the blade...right? Or perhaps a nozzle on either side. I was looking forward to running that test, but my daughter bought me the SS PCS so the Unisaw went to a friend. What do you think?

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I would not use expensive compressed air I would either duct cooling air from the motor or use a small fan to blow air through the blade.

Thanks Jim and James for the input.

Jack - interesting concepts. Based on the theory of the spinning blade carrying material - I wonder if some kind of passive fixed brush might remove that material. Similar to the brushes I have on my band saw wheels to help keep the tires clean.

Bill - the fan idea could work for sure.

I will keep thinking about this...

I have not experimented with my SS PCS yet and am still limping along with a shop vac for the moment. So I get a lot of dust out the top and some is also left in the cabinet. I will get a DC hooked up before much longer. But I experimented with my old Ryobi BT3100 to try and improve the dust collection without overarm collection. I think it is worth closing off the openings of the cabinet with sheet magnets and opening up the throat plate on the back side. If you can get more are moving past the back of the blade it helps reduce what is carried onto the top of the saw. But it is a small improvement, not a dramatic difference.

There are some good youtubes of overam dust collection. I cannot open the pictures on this post for some difference. The one I like best pivots out of the way when you can't use it. My tentative plans for the SS involve a 2.5 inch hose to the over arm and 4 inch to the cabinet from a 5 inch duct.

This is my portable saw. We use it inside houses with a 3hp four bagger, and no dust is left in the houses. Fine dust, like from cutting MDF is actually the easiest to catch all of, but you have to move a lot of air. I've since taken that router wing off because it's impossible, or at least not worth the trouble, to catch the dust. Air intake is 12x12 furnace filter over the motor, and everything else low tech closed up. I bought the Xactor overarm because I needed one quickly once, and it uses a 4" hose. That's 6" to the saw.