Change Sawstop DC port to 6"?

[David Giles]

Which would collect more dust from a Sawstop when using a 2-3Hp cyclone with 6" ducting? A) the standard 4" saw port which is tied with 4" flex duct to the collection guard under the blade or B) upgrade to a 6" port and just pull from the cabinet cavity.

The standard 4" port probably cuts the air flow in half. Using a 1.5HP DC with 4" lines, there is a lot of dust thrown out the front saw opening. Dust also builds up on the floor, partly because I don't always turn on the DC.

Suggestions?

[Warren Clemans]

There's lots of good information about this on Oneida's site. They recommend at least a 5" port for table saws. It seems like sure bet to use a 6" port if you're running 6" pipe to the machine.

[Kevin Groenke]

Dave,

I too have struggled with the DC on the SS, it seems like it should be SO good, but the cabinet fills up too fast. I know the DC isn't on as much when I'm not in.

I sealed up a lot of the holes in the cabinet in an attempt to make a venturi through the throatplate but I don't know that it helped much. I also made flexible vinyl "curtains" to the right of the shroud doors that are attached to the bottom of the tabletop with rare earth magnets. Again, I don't know how much these help, hearing from SS that most chips get past the shroud directly in front of the blade may force me to try the curtain strategy there as well.

As to the duct size, bigger is certainly better, we have a 25 hp dust collector and plenty of velocity, but choking it down to 4" just doesn't allow for enough volume. I've thought of putting a 5"(the line to the saws are 5") into the cabinet and leaving the 4" hose to the shroud in the center of that 5" tube. I'm sure this would generate a lot or turbulence, but if it sucks up the dust/chips that collect in the cabinet, I don't really care. I haven't done this yet because I would rather not start cutting and welding that still nearly pristine black cabinet. Perhaps hearing that somebody else is pondering improvements will motivate me to to have at it.

Interestingly enough I got an email from SS earlier today dealing with this very issue (among other things) they know that chips/dust get past the front of the shroud and are also looking for a solution.

Regards, let us know what you come up with

from SS:
Most of the dust that escapes the dust collection is shooting over the top of that shroud, the gap between the bottom of the table and the top of that shroud. We are looking for a good way to close it.
It has been reported to me by several customers that raising the blade slightly will cause more dust and material to be directed down rather than forward.

I typically replace these dust shrouds under warranty. I will send these with the replacement cartridge when I receive your “finger save” goods.

If you think about it drop a note in with the cartridge that will remind me to do so.

I absolutely don’t mind hearing from you.

Regards,


SawStop, LLC

[Howard Acheson]

>> I sealed up a lot of the holes in the cabinet in an attempt to make a venturi through the throatplate but I don't know that it helped much.

That approach works against good dust collection. Dust collection is about air movement, not suction. You should have about the same number of square inches of intake as you have of exhaust. For a four inch exhaust, you want about 12 square inches of intake. For 5" you want about 15". The objective is to maximize the CFM or airflow.

Another point, the dust coming off the blade is moving at over 100mph so you are not going to change it's direction until it slows down considerably. You can direct it toward the exhaust port with baffles which is probably the most effective ploy.

Trying to get dust collection through the throatplate is also doomed. Whenever you saw a board, the board effectively seals the throatplate and the only place for air to go is through the kerf. If you are getting sawdust on top of the sawtable, the only way to catch it is with some ducted collection above the table such as a blade guard.

[Ken Garlock]

David, I built a Bill Pentz type kit cyclone. I then piped my entire shop with 6" PVC pipe. I tried to keep the 6" all the way up to the machine. On my Bridgewood 10LTS, I enlarged the 4" dust outlet to 6" and brought the pipe right up to the metal cabinet, not much escapes the suction.

I enlarged the saw dust collector hole by first buying a 6" transition collar to attach the pipe to the cabinet. The actual enlarging was simple. Mark a 6" circle coaxial to the existing opening, and us a jigsaw to cut around the circle. After that, screw on the collar and slide the pipe onto the collar.

I don't know the cabinetry of the SS, but I bet you could so something similar.

PS, don't consider a dust collector of less than 3 hp. A cyclone is hands down the best choice. When I go to dump my collector barrel, it is just like dumping a barrel of wood flour.

[David Giles]

Since nobody yelled, "Stop, stupid!", upgrading the 4" port to a 6" looks like the best way to maximize air flow. I may use a "round takeoff" that has a rectangular attachment and bends 90 degrees into a 6" duct. That saves an elbow at the back of the saw.

The retrofit is some months away. I'll post pictures when complete. But it's clear that dust collection is a balance between the cyclone and ducting. If I can't get 5-6" ports on the machines, a bigger cyclone still can't pull enough air.

Thanks for the guidance.

[Brodie Brickey]

I'd upgrade to the 6" pipe if you've already got it.

Something to consider, air flow inside the cabinet will also be needed. Wood Magazine had a tip a couple months ago for a router table cabinet. The woodworker, put a 4" pipe to his DC on 1 side and didn't get the collection he expected. He drilled a 4" hole that was left open on the opposite side of the cabinet. His cabinet now stays free of shavings because the air flow drags the shavings into the DC. I'm not advocating cutting gaping holes in $3000 high precision machinery, but you might take up this type of discussion with more knowledgeable people in the DC community.

[Warren Clemans]

PS, don't consider a dust collector of less than 3 hp.

Why not? If you have a smaller shop and don't need to run long lines, a 2hp unit can give good results. More horsepower would be wasted unless you're planning to run 6 or 8" lines to each machine. Assuming short runs that terminate in 5" flex to the machine, I doubt if the extra horsepower would result in more airflow. This is my unscientific distillation of lots of reading that I did before purchasing my 2hp Oneida. As always, I could be wrong.

[Steven Wilson]

Collecting from the cavity will be worse that having flex run internally up underneath the saw blade. To properly collect dust from a tablesaw you need to collect from the top too. A brett guard, Excalibur, or similar will improve your dust collection greatly.

[Ken Garlock]

Why not? If you have a smaller shop and don't need to run long lines, a 2hp unit can give good results. More horsepower would be wasted unless you're planning to run 6 or 8" lines to each machine. Assuming short runs that terminate in 5" flex to the machine, I doubt if the extra horsepower would result in more airflow. This is my unscientific distillation of lots of reading that I did before purchasing my 2hp Oneida. As always, I could be wrong.

Well Warren, here is my thoughts. From my reading of Bill Pentz writings, it is necessary to maintain around 800 cfm air flow in order to assure that the very fine dust remains air born. In order to maintain that velocity you need a good size blower with a good size motor. To me that is a 14" impeller/blower and a minimum 3 hp motor. The goal of building a dust collector is to strive for a suction that will pull the chrome off a trailer hitch.

I have 6" PVC ducting running to my: table saw, router table, jointer, miter saw and band saw. The only places I use flex pipe is 6" to connect the table saw to the dust collector, and a 1 ft. run from the collector pipe to the miter saw hood. The miter saw is diagonally across the shop and the dust collector can easily handle small cut-offs of 1x1x3, anything bigger I toss in the trash barrel.

As always, my opinions are worth what you paid for them.

[Warren Clemans]

Well Warren, here is my thoughts. From my reading of Bill Pentz writings, it is necessary to maintain around 800 cfm air flow in order to assure that the very fine dust remains air born. In order to maintain that velocity you need a good size blower with a good size motor. To me that is a 14" impeller/blower and a minimum 3 hp motor. The goal of building a dust collector is to strive for a suction that will pull the chrome off a trailer hitch.

I have 6" PVC ducting running to my: table saw, router table, jointer, miter saw and band saw. The only places I use flex pipe is 6" to connect the table saw to the dust collector, and a 1 ft. run from the collector pipe to the miter saw hood. The miter saw is diagonally across the shop and the dust collector can easily handle small cut-offs of 1x1x3, anything bigger I toss in the trash barrel. As always, my opinions are worth what you paid for them.

You certainly aren't going to hurt anything by having the additional horsepower, but it's not necessarily money well spent for every shop. Pentz publishes a spreadsheet that includes a table with broad guidelines for various sized shops. For a 1 car garage using 6" pipe, he says (if I'm reading it right) that a 12" blower and a 2hp motor will develop sufficient airflow to collect all the nasty dust you need to collect. Of course, bigger shops require longer runs of pipe and therefore bigger motors and larger diameter blowers. My only point is that you can't say categorically that no one should consider a unit with less than 3hp. The bigger machine may not be necessary for small shop owners.

That said, I probably would have bought a 3hp unit except that shipping from Syracuse was vastly more than for my 2hp unit. At the time (maybe 6 months ago), the 2hp Oneida shipped in boxes by UPS while the 3hp unit came truck freight. The difference was around $300, maybe more.

[Art Mann]

Pardon me for for saying so, but there are a lot of folks who do not agree with the standards put out by Bill Pentz on his website. Despite the authoritative tone of his writings, he is not an industrial health professional and his opinions are only that. Many people, including myself, believe he greatly exagerates the risks of dust in a home shop environment. He believes the air quality standards in a home shop that is used for only a few hours a week should be more strict than current OSHA standards for the workplace, even though there is ample evidence showing no increased health risk if you work full time in such an environment. I am not trying to start an arguement and I won't comment any further. I just think people ought to know that a lot of smart people with much experience have alternative opinions to Bill Pentz.

[Warren Clemans]

Pardon me for for saying so, but there are a lot of folks who do not agree with the standards put out by Bill Pentz on his website. Despite the authoritative tone of his writings, he is not an industrial health professional and his opinions are only that. Many people, including myself, believe he greatly exagerates the risks of dust in a home shop environment. He believes the air quality standards in a home shop that is used for only a few hours a week should be more strict than current OSHA standards for the workplace, even though there is ample evidence showing no increased health risk if you work full time in such an environment. I am not trying to start an arguement and I won't comment any further. I just think people ought to know that a lot of smart people with much experience have alternative opinions to Bill Pentz.

You'll get no arguments from me on that point. There are plenty of examples of hobbyist woodworkers (my grandfather for one) who spent their weekends in a cloud of dust with no lasting ill effects. Pentz is on a crusade because he has suffered dust-related injury (so he says, and I have no reason to doubt him). I take his info with a grain of salt, but I find his site to be quite useful. I don't understand why he has such an abiding hatred (apparently) of Oneida , but that's not my problem.

Regardless of health claims, I like working in a clean shop. I like not having to wear a respirator all the time. I like having dust and chips collect in a central location that's easy to dump. Whether 800cfm at your table saw will make you less likely to get sick than 400 cfm, I like the bigger DC because it keeps my shop cleaner. If it has meaningful health benefits, so much the better.

[Charlie Kocourek]

Dave,

I too have struggled with the DC on the SS, it seems like it should be SO good, but the cabinet fills up too fast. I know the DC isn't on as much when I'm not in.

I sealed up a lot of the holes in the cabinet in an attempt to make a venturi through the throatplate but I don't know that it helped much. I also made flexible vinyl "curtains" to the right of the shroud doors that are attached to the bottom of the tabletop with rare earth magnets. Again, I don't know how much these help, hearing from SS that most chips get past the shroud directly in front of the blade may force me to try the curtain strategy there as well.

As to the duct size, bigger is certainly better, we have a 25 hp dust collector and plenty of velocity, but choking it down to 4" just doesn't allow for enough volume. I've thought of putting a 5"(the line to the saws are 5") into the cabinet and leaving the 4" hose to the shroud in the center of that 5" tube. I'm sure this would generate a lot or turbulence, but if it sucks up the dust/chips that collect in the cabinet, I don't really care. I haven't done this yet because I would rather not start cutting and welding that still nearly pristine black cabinet. Perhaps hearing that somebody else is pondering improvements will motivate me to to have at it.

Interestingly enough I got an email from SS earlier today dealing with this very issue (among other things) they know that chips/dust get past the front of the shroud and are also looking for a solution.

Regards, let us know what you come up with

from SS:
Most of the dust that escapes the dust collection is shooting over the top of that shroud, the gap between the bottom of the table and the top of that shroud. We are looking for a good way to close it.
It has been reported to me by several customers that raising the blade slightly will cause more dust and material to be directed down rather than forward.

I typically replace these dust shrouds under warranty. I will send these with the replacement cartridge when I receive your “finger save” goods.

If you think about it drop a note in with the cartridge that will remind me to do so.

I absolutely don’t mind hearing from you.

Regards,


SawStop, LLC


Kevin, Are they saying that they are replacing the original dust shrouds "under warranty" and that they consider them defective?

[David Giles]

Brodie / Steven, you are right about the cabinet dust collection. I'm not going to add an overarm collection port, but I hate to give up the standard shroud around the lower part of the blade. The current plan is to replace the 4" port with a 6" S&D pipe. The pipe will be attached to the cabinet with a flange located inside the cabinet. Inside the base, there will be a run of perforated 6" pipe and a 4" riser to the shroud, probably a 6x6x4 tee. Total open area will be greater than a 6" pipe area which should provide lots of airflow and targeted dust pickup at the floor and the blade.

[Kevin Groenke]

Kevin, Are they saying that they are replacing the original dust shrouds "under warranty" and that they consider them defective?


SawStop didn't go so far as to call the part defective, but they are sending replacements free of charge and acknowledged that they are exploring more durable solutions. I would presume that any SawStop users that experience this problem will be able to get a replacement free of cost or at a reasonable price. SawStop's stated warranty is 2 years, ours expired 10 months ago. I presume that SS is continuing "warranty" coverage because we are fairly heavy users, were early adopters and have(to some extent) on-going communications. I don't know that our "relationship" with SS is unique, but I doubt it. Most references to customer services from SawStop are positive, not exactly the norm in their field.

-kg

[Joe Jensen]

SawStop didn't go so far as to call the part defective, but they are sending replacements free of charge and acknowledged that they are exploring more durable solutions. I would presume that any SawStop users that experience this problem will be able to get a replacement free of cost or at a reasonable price. SawStop's stated warranty is 2 years, ours expired 10 months ago. I presume that SS is continuing "warranty" coverage because we are fairly heavy users, were early adopters and have(to some extent) on-going communications. I don't know that our "relationship" with SS is unique, but I doubt it. Most references to customer services from SawStop are positive, not exactly the norm in their field.

-kg

Kevin, I purchased in April of 2006. What serial number do you have? Can you better describe what changed, or show a pic?...joe

[Yuchol Kim]

Pardon me for for saying so, but there are a lot of folks who do not agree with the standards put out by Bill Pentz on his website.
I thought he was a DC guru and helped Grizzly come up with their cyclones. :rolleyes: :D

[Cary Swoveland]

I may be missing something, but I don't understand why it is necessary to replace the port with a 6" port to connect a 6" pipe, assuming you are keeping the 4" flex inside the saw. Why not just attach a 6"-4" reducer to the port?

Because of shop layout considerations, I put a 6" od wooden donut on my SS port and attached a 6" galvanized pipe elbow to that. That no doubt creates some turbulance, but it seems to work pretty well with my 2hp Oneida. Another thing that helps is to use the saw guard as much as I can. (I removed the pawls, btw.)

I accept some dust to avoid an overhead dust pickup, which I've had before and found very inconvenient.

Cary

[Paul Johnstone]

Is there anyway you can do dust collection at the blade guard, like with a Shark Guard system.

I just have a contractor's saw, which is about 15 years old, certainly not made for dust collection.

I have a cyclone, I put 4" ducting to the shark guard and 5" to the base.
That gets most of the dust. There's some dust left in the bottom, but it doesn't accumulate (in other words, there's a certain amount, about 2-3 cups, that is missed due to the fact the saw wasn't made for DC).

DC at the blade guard makes a huge difference. You can tell by smelling the air afterwards.. No more thick smell of sawdust.

I developed an allergy to Red Oak, and I used to get red marks all over my arms when using the tablesaw.. Since the change described above, my arms look a lot better.