Dust Control For Cabinet Table Saw
KUBasswood
| Posted in Power Tools and Machinery on
I have started to develop some health issues and need to do a better job of collecting dust in my shop. I have an 1 1/2HP Oneida Cyclone main dust collector, a second two stage 1 1/2HP unit for my two bandsaw’s and a air cleaner. All in all, everything works well with the exception of my Grizzly 1023X cabinet table saw. In addition to the main 4″ ductwork attached to the base of the saw, I have an Excalibur overhead guard that is also hooked up to my Oneida. But even with that set up, the majority of the dust settles in the base of the saw and creates considerable dust.
Any suggestions on how to better capture sawdust created by saw?
Replies
I have the same saw and had the same issue. Sawdust used to build up until it was nearly touching the motor. I solved it by increasing the collection hole to 6" and increasing my duct size to 6". Hardly any sawdust ends up in the base now. That is with a 1 1/2 hp Jet single stage DC.
If you don't want to go to 6", you could at least remove the dust port and cut an opening in the cabinet which corresponds to the inside dimensions of the port. The problem is that the 4" hole which Grizzly provides restricts airflow and makes a lip for sawdust to pile up. After you remove the port, you'll see what I mean. The larger hole is easily cut with a sawsall or similar.
Having said that, I was really surprised at the improvement from going 6". I easily doubles the airflow for a relatively small expense.
davidb
I'm a little confused by your post. You have a good set up. Is the concern that your DC setup is not getting it all from the base of the TS? I have the 1023 with the penstate overarm guard. It picks up pretty darn good but I don't think you find much that will get everything. I occasionally will open my base to check on things and see some dust left over in the bottom. It never amounts to much so I'm never to concerned. I too questioned mine until an accident proved how much it does get. I have one main line with a flex hose and quick connects to all my equipment. It takes me a few seconds to switch between all the lines from the various equipment. One time I forgot to switch back from the Jointer to the TS and made a few cuts. The amount of dust it threw out was shocking. I stopped and was thinking what the heck is going on and discovered the dc was running but to the jointer. I switched it and it solved the problem. Even with the OAG and the DC I still get a little dust. I just don't see how it can be avoided. I did see a tip in one of the mags where someone used rubber weatherstripping on the inside of the cabinet on both sides of the blade tilt indicator in the cabinet It filled the opening in the cabinet and was supposed to catch some dust that escapes via that opening. You could try that. Also there are air filter hoods that you can get and wear to keep the dust away. I've always been kind of claustrophobic and don't think I could take it. Another alternative is a box of paper filters. I wear those when I sand. They are light and don't get me too hot. Good luck on the quest.
If it moves, tax it. If it keeps moving, regulate it.
And if it stops moving, subsidize it.
First, keep in mind that the sawdust collecting in the bottom of your saw is not getting into the air. No cabinet saw has dust collection that will get all the interior dust. Dust collection is intended to cut down or eliminate airborne dust, not to empty out all dust.
As to your saw, something you can do is to create some air intake holes on the base on the side opposite the exhaust port. Dust collection is all about air flow, not suction. By having properly located air intake holes, you create an air flow across the base which will cause the dust that is now sitting in the base to be drawn toward the exhaust port.
As a general rule, you should have the same number of square inches of intake area as you have exhaust area. If you have a 4" exhaust port, you should have about 12 square inches of intake air.
Another approach is to build a sort of ramp across the inside of the sawbox so that dust is directed downward toward the exhaust port.
OK, I read the posts. I'm thinking about this.Let's think about the physics. If you're trying to remove dust, the best thing to do is, of course, is have the max. velocity you can get inside the saw -- the higher the velocity, the bigger the particle that can be entrained, the longer the residence time.You also want to minimize the head loss (suction loss) from the dust collector. The lower the suction head, the less velocity, etc.If you had a really long run from the collector to the table saw, then I can see where going from 4" to 6" would help. It would increase the suction head due to head loss in the duct. But if head loss wasn't an issue (a short run of duct work) it would slow down the velocity at the outlet to the cabinet and cause a lot of stuff to drop out.If you drilled a hole in the side of the cabinet, I can see how that might help -- you've created a non-obstructed flow running through the cabinet that would entrain dust particles. But if you drilled that big hole in the wrong place, the dust dropping down from the blade wouldn't get entrained, and would build up.But I can also see circumstances where these wouldn't work. What's the original poster's distance between their saw and dust collector? That's the simplest place to get an answer.
Pez,
Every time I read one of these discussions I reflect on my own situation and ask myself if it could be improved. I've got a Grizzly 1023 and, recently, bought a 1.5 Jet with canister. There is no question it's doing the job, I see chips in the bag and little residue in the cabinet. More importantly, however, the air in the shop is so much cleaner.I have a sense though, that since the DC more wood chips are being thrown on the cabinet saw top toward me. In other words, without the DC the blade forced more wood chips/dust into the cabinet. Now, perhaps the turbulence causes some of the downward draft to be negated.My saw is only about 4' from the DC with only one hook up at a time. When I think of the 850-1100 cubic feet of air being processed by the DC every minute it would seem only logical that the vast majority of that makeup air is coming from the louvered vents by the motor...perhaps causing a cross current situation in the cabinet. I wonder if there is a way to get more makeup air coming from around the blade itself. Maybe a perforated zero clearance plate? It may be my imagination but my sense is the DC works particularly well when I use the dado blades with the wide mouthed plate.
Hi BG,This is a truly interesting concept, and one that actually makes sense to me.Here's why.1. You're minimizing head loss because of nozzle effects from the places that air is actually coming into the saw.2. You're setting up the kind of flow pattern that would carry the biggest and smallest stuff right into the cabinet outlet.I have a 1.5 Hp Sears dust collector attached to my Delta Cabinet saw. It actually does a pretty good job, considering all I have on top is the typical blade guard. My expectations are lower because I know that the saw will throw some stuff off the blade.What impressed me most, though, was when I hooked up same dust collector to attempt to pull chips off my lathe. I jimmyed together a hood, and attached the 4" flexible duct to it. Air velocity at the outside of the hood was really negligible, which was what got me thinking about what I was really trying to do.I've worked on multi-phase flow problems (dust in air is multi-phase) in the past (I'm a prof of mech. engineering) and I've been trying to apply what I know there with the problem of dust collection. But here's the thing. It's complicated. And experimentation can often lead to good results.Might be fun to drill some holes in a disposable no-clearance throat plate and see what happens.
Is the reason it is working better when you are using a dado blade and a wider opening plate or is it because the opening is always covered when cutting dadoes?
Woodenhead,Good point. The most recent example, however, was while cutting tenons with the dado blade, the DC appeared more effective. But, I'm just guessing.I thought I noticed an increase in dust since the DC on the saw top. However, it could be that the dust has not increased but just not being thrown as far as before (as in off the table against my shirt, arm, etc.). The chips have got to be coming from the teeth of the blade and maybe with better downdraft things would be better. As your question implies, regardless of plate (zero clearance or otherwise) the opening is covered when ripping, cross cutting, etc. So maybe nothing will work.
It may not matter if there is some dust left inside the saw, but if the saw creates dust faster than the DC system then it may clog the DC ports. <!----><!----><!---->
I have a Jet Supersaw, it has a matrix of holes in the base that leads to a 4" port. When I am taking 'normal' cuts it works fine but as soon as I use a dado blade or if I am cutting thick stock the sawdust may collect enough to clog the matrix. <!----><!---->
The Jet SS has a bunch of openings between the table webbing and the cab... after I sealed up the gaps along the sides and back it helped a lot my theory is that it created a 'draft' across the blade then down through the matrix of holes...<!----><!---->
Howard's right in that it doesn't matter how much stuff collects in the base of the saw (well, up to a point...). What matter is that you're catching stuff that would usually fly around in the air where it can be ingested.
To that end, about the best you can do - in my opinion and research into the matter - is to somehow split the dust collection between the in-cabinet port and overhead blade guard. The in-cabinet port gets the bulk of the stuff that falls into the cabinet bottom, and the overhead collection unit gets some of the dust and chips that fly off the blade. It's nowhere near perfect. But since I set my saw up for this configuration I've noticed a very great improvement in the air quality in my shop.
I've also got a Grizzly 1023, and I simply modified the clear plastic blade guard to accept a Shop Vac hose that is hooked up to the 4 inch duct on my cyclone dust collector. Whenever I'm making a through-cut on something, the blade guard and hose are in place. I can see the chips and dust swirling around inside the guard, eventually being sucked up the collection hose.
The suction up that little Shop Vac hose is not that great though. I had it hooked up to an actual Shop Vac for a while, and that did help a lot. But it was a hassle having to turn on two items - cyclone and Shop Vac - every time I made a cut, so I went back, to the cyclone-only system. It works well enough.
I've also experimented with drilling holes in a zero clearance insert around the blade. No science to support my findings, but I suspect that it's not as effective as one would think (and hope) at first. Cutting a board of almost any size covers the holes while it is being run through the blade. I'm sure there is some dust-collection effectiveness going on once the board is past some of the holes in the insert, but that's just at the start and end of the cuts.
In the end, it might be worth doing, but it does not substitute for a well-designed over-blade guard/dust collection system. That, with proper airflow and suction, is probably the best place to put dust collection efforts, as that's where a lot of dust gets thrown into the air - and right at you to boot...
Zolton
If you see a possum running around in here, kill it. It's not a pet. - Jackie Moon
"I've also experimented with drilling holes in a zero clearance insert around the blade. No science to support my findings, but I suspect that it's not as effective as one would think (and hope) at first. Cutting a board of almost any size covers the holes while it is being run through the blade. I'm sure there is some dust-collection effectiveness going on once the board is past some of the holes in the insert, but that's just at the start and end of the cuts."I agree that a perforated zero clearance plate doesn't help. I does help to use the stock throat plate whenever possible. The extra room around the blade allows much more airflow. If you're ripping bigger pieces, you don't really need zero clearance anyway.davidb
David,
I've always used a zero-clearance throat plate because I'd read that it makes narrow and small cuts safer. I assumed that it also made cleaner cuts. Can you refute this?Chris @ http://www.flairwoodwork.spaces.live.com
- Success is not the key to happines. Happiness is the key to success. If you love what you are doing, you will be successful. - Albert Schweitzer
Hi ChrisMy thinking is that a zero clearance plate is necessary for 1)reducing tearout when crosscutting or 2)reducing the chance of small cutoffs getting caught between the blade and throat plate. I don't think they're necessary for larger ripping operations on solid wood, especially batch ripping where you generate a ton of dust. My personal observation is that dust collection into the cabinet is much improved with a larger gap around the blade. I don't see how a perforated throat plate would help though. When I use a sled, I completely remove the throat plate in order to improve airflow. This is with a large, conventional sled which covers the top of the saw. Removing the plate actually helps quite a bit.Try a few cuts both ways and see if you notice a difference. davidb
KU
Hate to say it but your DC system may be to small. If you haven't done so, visit Bill Pentz' site and get a good understanding of dust collection.
http://billpentz.com/woodworking/cyclone/index.cfm
You ultimately are the best judge of whether or not the system you have is working. Bill provides some tools that will assist you calculating your requirements.
While you are working this issue, get your self a few very good mask - 3M 8293 is very good - not cheap ($7-8 each).
Don
I'm sure you thought of this already, but since you have two dust collectors, why not hook one to the overhead and one to the cabinet? That would surely keep the cabinet clean and would mimic a larger cyclone. Just make sure you have a good canister on the single stage or it will be for naught.
davidbrum,I'm curious, when you drilled holes in your throat plate, did you drill them across the opening? In other words, take a 3/8" drill bit and drill holes all along the slit for the blade every quarter inch or so? I'm thinking about trying to emulate the down draft features of a non-zero clearance throat plate, while retaining the safety/quality features of a zero clearance.
That wasn't me BG, but I'm all ears if it works. davidb
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