SawStop DC questions - please help?

[John B Mooney]

Greetings all -

I recently got a Saw Stop PCS, and am trying to work out what I need to do to accommodate a ClearVue DC system. The saw has a blade guard/hood that encloses the blade quite closely, but it has only (I think) a 1.5" port on it. The port at the back of the saw is only 4", though it looks like it is connected by an interior duct to the bottom of the trunnion.

I've been reading my Bill Pentz, and am dismayed to discover that it looks as though this saw's dust ports (like most) are way too small to deliver the airflow necessary to collect the fines that a proper DC system should collect. The folks at Saw Stop weren't particularly helpful when asked about this problem - they said they'd done extensive testing and their system worked really well, but it's pretty hard to square that with Mr. Pentz's data, if I understand it correctly.

I'm reasonably handy, but relatively new to woodworking and have no experience with modifying power tools, so I'm one of those who is somewhat flummoxed by this problem (definitely NOT excited at the prospect of cutting a big hole in the back of my shiny new tool), and I'm hoping someone here can help me with a way forward. Has anyone adapted their SawStop for bigger ports? Is it indeed necessary? If so, how did you go about it? Did you need to change the size of the internal ducting as well as the port size? Was this possible, and if not, does it make any sense to change the external port to 6" if the 6" port will be served by a 4" internal duct? Also, do I need to discard the pricey new hood that "works really well" and get a Shark Guard with a 4" port?

<rant> I'm not an engineer, and I don't know how critical all of this is, but I confess I'm a little grumpy that the saw I just laid out a premium price for doesn't have larger ports already, since the evidence seems pretty convincing that it should. I can't imagine a 6" port asnd duct would be much more expensive than a 4" system, especially when considered as a percentage of the price of the saw! </rant> (Thanks, I feel much better now...)

If this has been addressed before, I apologize, but I searched and didn't find it. Thanks in advance for any thoughts, ideas you may have.

Best,
- John

[Nick Lazz]

To be honest, I think you're getting worked up too much. My cabinet saw produces the most dust in my shop. I have a CV and have recently enlarged my cabinet to accept a 6" pipe. Although that helped, I still have nothing above the blade which probably accounts for 25% of the dust produced. Try yours out the way it is. It is likely the 1.5" port on the blade guard is insufficient but I'm betting it will work just fine. Run 6" all the way to your saw to a 6x4 reducer at the saw. You can minimize CFM loss by not using flex. If you aren't happy, modifying your cabinet should be pretty easy to do.

Good luck and let us know how it turns out.

Nick

[Peter Aeschliman]

Agreed.

I haven't read every word of Bill Pentz's website, but from what I remember, one of the principles behind his CFM/FPM requirements is that the dust collector has to compete with the turbulence created by the spinning tool. So i think it stands to reason that if the dust collection hoods on the machine are designed to utilize the turbulence (rather than fight against it), the CFM requirements shouldn't be as high.

That's the case with the PCS... the shroud around the blade below the table does a really good job. I'd take a 4" port and a good shroud over a 6" connection and no shroud (like most old and some new cabinet saws) any day. Same goes with the blade guard. It channels the turbulence thrown off of the blade to send the dust into the hose.

I have the PCS with a 3HP dust collector. No dust whatsoever. Can't even smell anything in the air. The only case when I get dust is when I'm trimming the edge of a piece... meaning the blade is exposed on the left side as it cuts. That does throw a lot more dust than I would like. Other than that, it's flawless.

So I agree with Nick. Try it first before throwing any money or time at it. Modifying the cabinet and the blade shroud to a 6" hose could be really tricky... remember that the blade assembly needs to tilt, raise, and lower.

[John B Mooney]

Thanks both for the replies. Your suggestions to see what happens before cutting holes in my new saw is both sensible and comforting (and that's a rare combination!) I'll do as you suggest.

A follow-up question, if I may: should I fit a boom to get the dust from the shroud to the duct running to the back of the saw, or should I work out some way to drop an independent duct from the trunk line directly to the shroud? Either way, should I try to ease the radius of the first turn out of the shroud, or live with the 90 degree turn that most of the booms seem to require?

Thanks again for easing my mind about this, and I'll definitely post an update when I've got it worked out.

[Erich Weidner]

I too just bought this saw, and am facing the same choices. I have been looking at the Oneida line, but am lost for as to what to buy and whether or not to modify the saw.
As you observed, even if we drill out the port to accept a 6" hose at the back we still have the problem of what to do with the 4" hose and hookup inside the saw. I have the same question about the upper blade guard. My dial calipers measured ~ 1/38 I.D. where the hose hooks up to the guard. (I started another thread on this subject, and emailed Saw Stop, they said they would forward my questions to engineering and get back to me. This was just yesterday, so it may take a while to get a response).

-Erich

[Philip Rodriquez]

I have the ICS w/ and Excalibur BG. I simply have a 6/5/4 wye and it works great. IMHO, any above the table DC will amaze you. Start with what's easy and go from there.

[Prashun Patel]

I have the PCS and went thru a similar thought process last year.

Non-scientific experience alert:

I believe my old Sharkguard with 4" port to be superior to the Sawstop blade guard. I use a shopvac on it, and still get some spit out out of the front of the guard even when ripping the center of a board. It's worse when trimming edges as noted.

The 4" port on the Sharkguard got almost everything regardless of where I was cutting.

I concluded that the biggest problem is the size of the above-blade port on the SS. All other factors (port splitting, DC HP, # bends) were second to this for me.

[Craig Behnke]

John,

I'm in a very similar boat,...I'm relatively new to woodworking and I just picked up the same saw recently (congrats on a nice saw and a great DC system). Prior to that, I spent weeks reading the Pentz info also.

IMHO, keep the sawstop blade guard/hood, don't modify the ports, run it stock for a few weeks and if you are truly disappointed in the performance...THEN you can make changes. Here's why I say that (and remember it's just my opinion, but it's based on experience with the same tool and similar DC setup as yours):

Bill's info is great but don't be dismayed. In my humble opinion, Bill's info describes the absolute perfect scenario for DC that can produce results 10 times superior to the air quality in the average living room. It's not practical (or needed) for all woodworkers to achieve that level of DC (but for some with serious lung health problems it is). If you truly need that level of DC, then you should wear a respirator to combat the current horrible conditions in your living room while watching TV. The sawstop system works incredibly well but it's not going to lower the fines to 10x less than your living room. Don't let excellent (sawstop's current setup) be the enemy of perfect (Bill Pentz' ideal setup).

I have a 3.5 hp cyclone DC (a PSI Tempest) running 6 inch ducts to the machine, then splitting into two 4 inch ducts; one that goes into the cabinet, and one that reduces to fit the sawstop bladeguard dust collector tube. The dust created is almost imperceptible. I do not have one of the air quality testers, but to the naked eye, nose, and lungs, there is almost no dust.

I also contemplated modifying my saw to use a 5 inch into the cabinet. I chose not too because it would mean a fair amount of modification work to my existing DC duct work and the table saw. I decided that the necessary work vs performance gain trade off was not worth it for me.

Sawstop did a good job integrating a DC system that is very effective AS IS right out of the box and more than good enough for the vast majority of hobby woodworkers. IMHO, there is no need to modify it and you save the time and effort it takes to do a good mod.

If you still want to mod your sawstop, you may not need to cut your cabinet. There are two removable panels on the sawstop that you can use for the larger port. Yes, if you change the port to 6 inch, you would not see any material performance improvement unless you change the internal ducting to 6 inch also.

I know exactly what you're going through. I went through the same things over the past several months as I researched DC before I bought. If I had to impart one thing to people that are in the same DC research process right now is to remember Bill's info is closer to the perfect ideal DC and that may not be attainable for most woodworkers but don't let that stop you from an excellent DC setup that will serve you incredibly well for years to come. Get that DC hooked up and get cracking on a project, you'll have a ton of fun with the new tablesaw and CV DC.

[Rick Prosser]

I have the PCS with the SS dust collection kit. Running a ClearVue with a 4" hose connected at the base, and the smaller hose running from the base up top to the blade shroud. The suction in the smaller hose is much less (as expected).

Works OK for simple ripping, but there is some spray out when trimming edges. Also, the blade shroud gets clogged easily when edge trimming - it sucks up the smaller edge scraps that block the narrow airway. I expect a dedicated 4" hose to a Sharkguard could be a huge improvement.

I wonder if the 4" sharkguard suction would work against the 4" base suction...?

[Peter Aeschliman]

John,

As to your question of how to plumb the hose to the blade guard- I just did a drop from the ceiling. Seems a lot easier to me that getting that big apparatus over the extension table.

Plus, if you're like me, you sometimes stack up your stock on the extension table as you're milling it. Having that pipe over the extension table would get in my way.

That said, I'm going to contradict myself a bit. If you end up going down the path of upgrading your blade guard dust collection, I'd go with an excalibur over arm blade guard instead of the shark guard. Since the PCS comes with a riving knife, you could just keep it in the saw full time. The excalibur presents a few advantages over the shark guard in my opinion: it can be used for non-through cuts (dados, rabbets, grooves, etc) since it's not attached to the saw. It also has a 4" hose, so it will do a better job collecting dust when you're trimming an edge. And you can swing it out of the way if you need to.

[Prashun Patel]

Rick-
I used a 4" Sharkguard on my previous saw (a jet hybrid). I had a 1.5hp single stage dc powering both ports. I used flex hose and about 8 feet of pipe to each port. The dc was superior to the SS I have now running a shopvac to the top.

[David Giles]

Here is a link where I upgrade my Sawstop to a 6" port.
http://www.sawmillcreek.org/showthre...port-to-6-inch

[Erich Weidner]

I asked Saw Stop about what the recommend for fine dust and chip collection and received a response.
Sharing for the benefit of all:

My Questions were:
Looking at the interior of the saw, there is a 4" hose which connects from the dust collector shroud (internal) to the port on the back of the cabinet.

1. What is Saw Stop's recommendation for dust collection to get up in the 900 - 1000CFM range?
2. Is there a different internal piece which will support a 6" hose internal to the cabinet?
3. What is the best way to run 6" duct to the saw? (Drill a bigger hole & remove the internal hose?)
4. Last question, according to those same sources I can only get at best 50cfm out of the 1-1/4" overhead dust collector. This is supposed to be balanced vs the "main" input to match the CFM of the branch. Is there another part which will not restrict airflow and allow for a 2-1/2" hose?

And the answer from Saw Stop was:
Our senior engineer says:
That level of air flow is not necessary to achieve good dust collection with our saw. We designed our dust collection to be far more efficient than any other table saw and we just don’t need that much air flow. There is no advantage to trying to go to a 6” duct or 2 ½ for the overhead. If one wants the cleanest air, one should get a smaller dust collector for our saw and invest the extra money in a whole-shop air filter. That will be far more efficient overall.

(I can certainly attest to the efficiency of the dust collection on our current cabinet saws. )

[Patrick Galpin]

John, I too have the SS 3hp PCS unit and have been using it for the past 4 months or so hooked up to a 3 hp cyclonic DC, the DC has an 8" port that immediately splits into three 4" ports. I connected each of my major dust generators, TS, 12" jointer and 20" planer to one of the 4" runs as the first connection to that run and have not had any issues with any of my machines clogging.

My piping is 4" PVC and each run then carries on to other smaller machines around the shop. I get very little dust anywhere. The 4" outlet for the SS is fine, I have run a 2" hose to the blade guard and that picks up all the dust from the top of the cut surface, obviously doesn't work for dadoes of my TS sled.