Dust Collection FAIL? Or Expectations FAIL?


rgdaniel

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Hi folks... I have a very small shop, 8x24 plus a table saw in an adjoining section, sharing space with my wife's car in winter at least... but I decided last year I should make room for a dust collection device, since my table saw was filling with dust to the point where it was interfering with the belt... so I got this decent Delta two-bagger, similar to this one I think:

http://www.deltaportercable.com/Products/ProductDetail.aspx?ProductID=24010

And I invested in the Rockler Dust Right accessories that allow me to swap the hose from machine to machine as needed. The unit sits centrally located, with a reasonable length of hose, no long runs.

Seemed like it would be a huge step up from my shop vac, which I blamed for being insufficient to keep the table saw from filling with sawdust. (And yes, blamed myself for not staying on top of the situation).

But much to my surprise, the other day, after months (light use) of faithfully using the big-ass dust collector on the table saw, it was once again full to the brim with sawdust, requiring a thorough vacuuming, which is awkward for me to do (and why I avoid it I guess). The area right near the dust port stays fairly open, but the dust had built up on the opposite side, as before.

Meanwhile, my Delta X5 jointer ( http://www.deltaportercable.com/Products/ProductDetail.aspx?ProductID=17162 ) has always had this tendency to shoot more chips out the top of the jointer than it does out the dust port... even with the new bad boy dust collector attached, it doesn't seem to be acting any better in that regard than it did with the shop vac. I have to wait like 30 seconds after each pass for the chips to stop flying towards the workpiece.

So my question: Is this just normal behaviour for these things, and I should just suck it up (haha)? I've got no way to implement a bigger dust collector, so that's not an option... do I just need to do my housecleaning stuff more often?

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So not sure which table saw you have. I had a PM64, which is a contractor saw, and its version of "dust collection" was an ill-fitted plastic bottom with a 4" DC port. If you looked under the table, the corrugations above the "dust box" let in a ton of air. It wouldn't pull dust from the top of the saw, it would just pull excess dust from inside the dust box. By 'excess' I mean it would pile dust along the sides forming a funnel to the dust port. It actually became more efficient once that funnel formed ("more" being relative). It would, however, pile up to the point of hitting the belt after awhile.

If you have a contractor saw, I think this is pretty common. Oh, I did make an insert that attempted to plug the 40+ s.f. of open space in the back of the box. Okay, I exaggerate (a little), but closing one of those things up is like filling the Grand Canyon with self-leveling compound.

Now there are extreme measures you can do to make a contractor saw more dust collection friendly, the best I've seen being to build a cabinet completely around the beast.

Have no idea about the jointer. My #7 doesn't even have a dust port.

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Nope, just one single 4" flex hose, directly connected to one machine at a time.

I would check your jointer at least to make sure that it isnt plugged up. I know mine can get plugged up and it spits it at me. But when it is clear, it goes just fine.

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If you have a contractor saw, I think this is pretty common.

Nope, it's a full cabinet... The only place not closed in would be around the crank at the front... I could put masking tape over that gap I suppose, but I'd be removing it every time I needed to angle the blade... worth a shot I suppose, as it would be easy to replace the tape... or maybe something that flips out of the way temporarily...

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Nope, it's a full cabinet... The only place not closed in would be around the crank at the front... I could put masking tape over that gap I suppose, but I'd be removing it every time I needed to angle the blade... worth a shot I suppose, as it would be easy to replace the tape... or maybe something that flips out of the way temporarily...

I have a General 650 and it fills with dust a chips pretty good. nI have a 2.5HP cyclone. I run it most of the time and it keeps the dust from getting in to the air. That is what counts. I usually just wait till it gets full, turn on the DC, then blow a bunch of compressed air in the cabinet to blow the dust around and get sucked up. I would worry about that much. The jointer, that sucks when it is full of dust. it will effect its performance. It did on mine anyway..

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Tablesaws are horribly ill sealed. I've got the magnets you get every time you get a new phone book all over mine. I have a 3HP Dust Gorilla and if I forget to turn on the DC often enough, I'll get sawdust stuck in the cabinet and have to use a stick to clean it out. But, the DC unit doesn't let any dust become airborne and even when I was running my old Jet DC1100, the same was the case. So, just be diligent about firing up the DC before each cut and letting it run a second or two after and it should work. Have you looked to see if the jointer is clogged? It sounds like it is.

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Tablesaws are horribly ill sealed. I've got the magnets you get every time you get a new phone book all over mine. I have a 3HP Dust Gorilla and if I forget to turn on the DC often enough, I'll get sawdust stuck in the cabinet and have to use a stick to clean it out. But, the DC unit doesn't let any dust become airborne and even when I was running my old Jet DC1100, the same was the case. So, just be diligent about firing up the DC before each cut and letting it run a second or two after and it should work. Have you looked to see if the jointer is clogged? It sounds like it is.

Magnets, good idea!!... reminded me that I saw somewhere, somebody did a custom plywood thingy to cover the hole by the front crank, with rare earth magnets to attach it... might try that.... and yeah, gonna check the jointer for clogs first thing tomorrow... I think it's due for its first ever blade change, so that will be an adventure... apparently I need a jig?

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Just a suggestion to check. Those collectors typically have a metal cross shaped insert spot welded in the housing where the hose attaches. It's so moron's can't fit there hand in with the motor running :blink: . Anyway, planer and jointer chips catch on it which seriously cuts down on the airflow. If you have it, might want to wrench it out with a pair of pliars :)

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Nope, just one single 4" flex hose, directly connected to one machine at a time.

I have the same hose and a 1 hp dust collector, but never have had problems with a table saw filling with dust.

As far as the jointer, if the chips get blown *away* from the dust collector port, that's just the tool, I'd think; not much the DC is going to do?

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As far as covering the slot for the tilt mechanism, I found sheets of rubber magnetic material at HD. They are sold to cover up the heating registers.

You will probably find that there are lots of other places for air to get into the base of the saw. Check under the table top, many saws have a significant gap. Several manufacturers have gone to a hood around the blade that is connected to the DC system with nothing to pick up the dust that scatters around the cabinet.

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Okay, the name of this thread should be changed to "Maintenance FAIL" or maybe just "Bob Daniel FAIL"...

Here's a photo of the inside of my jointer:

5030085273_1840bd5e0f.jpg

Guess the lesson here is: don't rely on the dust collection... get in there and clear out the dust every couple of months or so...

I also blogged this, so that others may learn from my epic FAIL...

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So was all that dust in the jointer from a plugged hose or not having the DC turned on, or is there something else going on? It definitely shouldn't be piling up like that no matter what. It's hard to tell from the picture, but is that the hose port half-way up the right side? It kinda looks like there's a chute leading to it from the cutter head. Is the dust maybe getting out around the cutter head shaft or something?

If everything is set up correctly, there's no way that should be happening. If that's a "design feature" of that particular piece of equipment, then it's a major design flaw because that's a huge safety/fire hazard. If everything checks out okay and it's still doing that, I would suggest cutting a hole at the very bottom and attaching a smaller hose that joins with the main hose to keep the bottom cleared out. (See the thread on the home-made overhead tablesaw dust collector for how to do it.) Barring that, you could also put a piece of plexiglass over the front so that you can see when it's building up. (I'm assuming you removed a metal plate to see all that dust.)

Anyway, I would suggest getting a book or two on dust collection setup and go through those. Some of the things you have to look for can seem counter-intuitive, and it's not just about how the hoses are run. It's also about configuring the machine itself.

On the tablesaw, if dust is just piling up in the corners resulting in a "funnel shape", this is actually normal. I'm assuming you basically have a square box with the hose at the back end. When the collector is on, you're forcing the air to make a right-angle turn coming in from the top and then having to go out the back. While this is easy for the light individual air molecules, it's not so good for the heavy wood chips. Result: the air changes direction, the chips do not. This is exactly the concept a vortex seperator works on. You are also getting eddy currents (swirls) in the air in the corners, which produces a low-pressure area, which also encourages the chips to collect there.

As long as the chips continue to be pulled out and don't actually clog up the hose, you're fine. If you want to get fancy and make it more efficient, run it until the corners fill up with chips again. Now take off the back (if you can) and try not to disturb the dust. Look at the shape it's making. Mark the edges of the shape inside the box with a marker or something if you can. Once you have that done, vacuum out all the dust and clean the sides. Make some heavy cardboard triangles and duct tape them inside to make that same shape and put it back together. Now when the dust gets there, it should continue out the hose. You're just making a big funnel, so it doesn't have to be perfect. that should improve things a lot.

Incidentally, closing off all those holes in your table saw can actually make things worse, not better. People sometimes confuse vacuum (suction) with airflow (a force pushing something). If you close everything down super tight, the only place air can get in is basically through the blade opening. At first you might think this is a good thing, but if, for example, you are using a zero-clearance insert, you are effectively stopping down the air intake to a tiny hole.

It's the same thing as plugging up your vacuum hose. The chips and dust are pushed by the airflow, not pulled by the vacuum. All the vacuum does is make the air move. It's actually recommended on inserts to drill a fairly large hole at the front of the slot so that air can rush by the front of the blade into the machine and take the dust along with it. (This is why there is dust collection built into the better blade guards now. It's just not possible to get enough airflow past the insert to capture the dust that's above the blade.) Another way to help lessen those dead spots you have is to drill a small hole right in the middle of where the dust is piling up. In this case it shouldn't be more than about a quarter inch or so. This way there is a little bit of air let in through those trouble spots, which pushes the dust towards the hose. Depending on how the frame of your particular saw is set up, those openings around the height and tilt handles may actually help to allow a cross current to enter through the front and exit through the hose, thereby taking more dust with it. Covering them may just be further choking the collector.

When I enclosed the open base on my Delta contractor's saw, I built several slots into it so I could regulate how much air is going where. It also has a bunch of holes drilled into it that have helped get rid of any deadspots, and it is much happier now. Oh, and one last thing I did when building the box was to put a sloping bottom in it so that any chips that do fall to the bottom slide towards the port. There are still little dead spots here and there, but they never are able to build up very far.

Hope all that gives you some ideas.

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So was all that dust in the jointer from a plugged hose or not having the DC turned on, or is there something else going on? It definitely shouldn't be piling up like that no matter what.

Lots to think about there, thanks... I'm going to keep an eye out to see if I can learn anything else... but mostly I'm just going to check for sawdust buildup more often...

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Nice post, M. Never heard of the idea to drill a large hole ahead of the ZCI slot, but makes complete sense.

I definitely second the airflow vs vacuum argument. My router dust box has a 4" port and a 2.5" port to the fence. I thought the gaps around the bit and other leakage would be enough to support the airflow needed, but ultimately I made a second 2.5" port with a partial cover that rotates to modulate the amount of air. Made a huge difference topside.

Until a couple posts into this thread, I forgot that most cabinet saws are just a box with a dust port. The SawStop PCS has the port connect to a hose that goes to a shroud surrounding the blade. The box does get loose chips, but nothing major.

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All good comments about air flow around the machines producing the chips. And a good catch on the dummy guard on the intake inlet to the DC.

From the picture of the dust and chips settling into the base of the planer, it is pretty clear from the even distribution of the various colored wood chips that something is amiss with the chip deflector. The deflector is suppose to send dust and chips down the deflector to the hose connection. The angle of this metal chute is intended to decrease the amount of airflow necessary to move the debris out of the machine. I would investigate if the space between the chute and the side walls of the cabinet are not touching. I know this is stupid to suggest, but is there any chance the top portion of the jointer was mounted backwards to the base? If no, then perhaps a few pieces of sheet metal and a few pop rivets can help redirect those wayward chips. I've modified some of my machines using card stock from paper tablets and painters tape. Sometimes just a minor deflection can be a huge improvement.

I would also verify that the DC is producing the promised air movement. Fine Woodworking and other magazines have run articles on this topic and probably not to anyone's surprise, not all DC produce the promised CFM or inches of Mercury claimed. I'm not familiar with your model of DC, but I'd seriously investigate the CFM/inches of Mercury promised in the technical manual. With the DC running, what is the air current like? Can you vacuum the dust off the shop floor? How about a pile of chips and dust? Is it possible to hook up a larger pipe/hose? As others have pointed out, air flow is everything. Given the size of your DC, with the hose in your hand, you should be impressed by the volume of dust and debris you can pick up out of a pile on your floor. If not, then the machine is the problem.

If the airflow is weak in the hose experiment, I'd inspect the impeller. Check to see that it has been installed correctly or has any damage. Investigate if there has been a recall on your machine for faulty impellers. It has happened in the past. I'd also check the filter bags (if it has filter bags). When the DC is on, are the bags stiff or do they flutter? Flutter is good. That means there is plenty of bag surface. Stiff enough to sit on is bad. Very bad. That means there isn't enough bag surface area for air to escape. Air can only come in as fast as it can get out of the filters.

For many years I used an old ShopSmith Dust Collector. Just their standard 110vac model. Just as a goof, I bought a custom bag from a filter maker in Florida at a trade show. The bag was as shaped to fit the top of the DC and then was tapered to go out a couple of inches larger than the diameter of the original bag and straight up for 5 feet. The bag had loops on the top, which were threaded with two lengths of PVC pipe and suspended from the ceiling. When off, the bag slumped like a limp sock hanging on a clothes line. When the machine was on, the bag slightly fluttered. I would have made the bag bigger, but I only had a 10 foot ceiling. The bag was made from singed felt and I would clean it a couple of times a year and then recharge it by throwing a 5 pound bag of flour into the collector. I also added a trash can cyclone just a head of the DC to reduce debris that could damage the impeller or clog the collection bag. Long story short, that larger felt bag so improved my DC that I didn't need to upgrade to a larger machine. Until I had to give up that shop I did toy with the idea of making a plenum and having a series of filters dangle down from the plenum, each terminating into its own 5 gallon bucket. My idea was to see at what point the amount of filter surface area maximized the performance of the DC.

Good luck!

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Oh, and just to be fair, a lot of this I got from various books and videos. I believe some of it even came from sources mentioned in Marc's episode on dust collection, but I don't recall specifically which was what now. I've assimilated so much knowledge here that it's history becomes a blur. I believe he mentioned one particular source that was the go-to guy for DC info, but I don't remember who it was. I'm assuming someone here will remember and have the link. Guess I need to go back and watch Whisperer reruns :lol:

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is there any chance the top portion of the jointer was mounted backwards to the base?

Don't think so... but it made me think!... but the access panel is at the rear of the unit, same as it looks online, so I don't see how it could be backwards... it wouldn't be the first time I've assembled something bass-ackwards though, so I had to think about it... :)

With the DC running, what is the air current like? Can you vacuum the dust off the shop floor? How about a pile of chips and dust? Is it possible to hook up a larger pipe/hose? As others have pointed out, air flow is everything. Given the size of your DC, with the hose in your hand, you should be impressed by the volume of dust and debris you can pick up out of a pile on your floor. If not, then the machine is the problem.

I think the machine is fine, its ability to collect debris is indeed pretty impressive, just have to get in the general vicinity, and the sawdust comes to me...

When the DC is on, are the bags stiff or do they flutter? Flutter is good. That means there is plenty of bag surface. Stiff enough to sit on is bad. Very bad. That means there isn't enough bag surface area for air to escape. Air can only come in as fast as it can get out of the filters.

I'd say its somewhere in between those two scenarios... no obvious flutter, but you can poke it fairly easily... and it does manage to fill up the bottom bag without difficulty, so it seems to be doing its job... in any event, it's moot, as I've no room or budget to expand or replace the DC itself, unless it flat out stopped working...

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I have the same Delta jointer and have to really watch for plugs. When a plug occurs it causes chips to be thrown from the table. Unplugging is a PITA. I have to reach way up into the jointer from the dust port and pull it out. :angry: It usually happens when I plane the face of boards >4".

Oh, interesting... can you SEE the plug? I just had the back off mine again, before I read this, and I did reach a little ways up the dust chute, but there was nothing obvious... I'm not sure my arm will reach that far, but I'll give it a shot... is it safe? I don't want to slice my fingers open and bleed all over the inside of the jointer... just concerned about rust... ;) ... but yeah, that rings true somehow... the chips come flying out along the face of the planer, in the direction the blades are spinning, ie towards me, and AWAY from the dust port... seems like something must be plugged....

Planer was doing the same thing at one point, come to think, and it turned out to be plugged with chips as well, to the point where it was difficult to crank the height up and down... I sense a pattern developing...

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