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So after two weekends in a row of cutting MDF, I've come to the conclusion that I have to do something about dust collection and my saw. Basically I have this shop-vac that I'm planning to use as a portable dust collector. My real question is...

Aside from building an enclosure around the inside of the stand, and a suitable attachment point for the shop-vac, is there anything else that I need to do? I'm planning to use some left over 3/4" MDF that I have for this project and some bolts.

My thoughts are... At this point... something is better than nothing!
 

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Do a Google search on a guy named Chuck Lenz who's done alot of DC mods to his Delta contractor saw. He's got some original ideas that he claims are pretty effective. He tends to hang out at Sawmillcreek.org.
 

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Rob; Sorry but shop-vac aint gonna hack it. Even with 4" system MDF will still put dust in air. You have to go with 4" dust collector at a minimum. MDF is just plain ole nasty. If this is the only time with it, spend on a 4" system and hook up saw. IF you intend to work with it full time everyday then you need an Oneida setup or the like. Also I suggest you buy and install a ceiling mounted unit. JDS makes a great one.:yes: I run a Delta contractors saw everyday, hooked up to a 4" dust collector and a JDS ceiling mount, it really works well. Not 100% but to achieve that level will cost a fortune.
Jack
 

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The shop-vac is gonna have to do until I can afford a $300 system. Like I said, it's gotta be better than nothing at all.
 

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I use my shop vac. A box fan in the window at the back side of my shop, with a window open at the front of the shop, it creates a pretty good airflow that carries the dust away fairly quickly.
Of course this all depends on your climate as well.
You can purchase a dust fitting that attach's to the bottom of your saw and attach your shop vac. Also a cover for the back side of the saw around the motor assembly. This works well for me until I can afford a good whole shop dust collection.
 

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Rob,

Even with a good point-of-use dust collection system you will still need an air cleaner to capture the airborne dust. JDS makes the best one I have seen. You can get it for a good price on Amazon.
 

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So after two weekends in a row of cutting MDF, I've come to the conclusion that I have to do something about dust collection and my saw. Basically I have this shop-vac that I'm planning to use as a portable dust collector. My real question is...

Aside from building an enclosure around the inside of the stand, and a suitable attachment point for the shop-vac, is there anything else that I need to do? I'm planning to use some left over 3/4" MDF that I have for this project and some bolts.

My thoughts are... At this point... something is better than nothing!
No question about it, that MDF is nasty stuff! Unfortunately, I don't feel a shop-vac will do the job in the traditionally way of enclosing the base. I think what you need is a clear blade guard connected to your dust collection hose. Not sure if a shop-vac would do the job, but certainly worth a try!

This is my modification to a PowerMatic 64A contractors saw. I highly recommend it for capturing dust that normally falls on the floor. This upgrade captures better than 90% of the sawdust.



Here's the link to my Photo Album on this project Click on the individuals pictures to view comments below the pictures : http://www.ncwoodworker.net/pp/showgallery.php?cat=845

-Don
 

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Thankyou Scott, I just joined the forum and noticed that you refered Rob to me. First I would like to say that the dust collection design that I have for my Delta 34-445X Contractors table saw is hooked up to a Grizzly G1029 2hp dust collector with low micron bags. Some of you may look at this picture and say well what about the back of the saw ? I've seen many people fully block the back off with a piece of plywood, and I've also heard of people that forget to take it off before attempting to tilt the blade and as a result pushed the trunion out of alignment, I even heard of one guy that cracked the trunion, which cost him alot of money for a new trunion, not to mention the down time waiting for the part. I'd also like to point out that the cabinet should not be closed up air tight, the DC needs to get air from somewhere, so I chose to close every thing else off and only partially block the back. I filled the gaps between the cast iron top and the cabinet with closed cell foam and closed the opening where the blade tilt slot is in the front of the cabinet with a piece of magnetic sign material. Now all the fresh air needed for the DC comes from the back of the saw and nothing is in the way in the back of the cabinet during blade tilting operations. I worked on this design for over a year, also improveing the design of the dust hood underneith for better dust collection and a more convieniant location of the dust port for hookup. It all works extremely well. Any dust ontop of the table can only be cured with a over the blade DC system such as the Shark Guard. Other improvements that I have made to this saw are, wireing it for 220 V, adding a Fenner Drives PowerTwist Link Belt, relocating and upgradeing the power switch with a paddle switch up by the fence rail, and adding a Delta 50-390 outfeed support. I have had this saw since I bought it new in 1995 with the 30" Unifence and a mobile base. I have no plans of selling it anytime soon, it's been a great saw.
 

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contractors saw dust collection

Rob, you have got to get at least a 1 1/2 h.p. D.C. and hook up to the saw like woodchuck1957's set-up. That 4 inch vent sucks up everything that falls beneath the table. You should also get a 1 micron (or better) cartridge filter for your lungs' sake. A zero clearance insert also helps. It should be illegal to sell table saws without D.C.s. Very bad for your health.
 

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Contractors Saw Dust Collection

The dust hood for undernieth the saw I have two sizes built from a heavy gauge galvanized sheet metal, 12 1/2" X 12 1/2" and 14 1/2" X 14 1/2". They are a vast improvement over the standard plastic dust hoods that are sold for these types of saws. No bending of the dust collection hose or elbows undernieth the saw are needed that would reduce air flow efficiency in the dust collection line, plus the dust comeing off the saw blade has a larger target to hit.
 

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Hey Chuck, glad to see you over here. I copied your dust hood for my saw out of plywood, after I saw it on another site. It works great. Thanks for sharing your idea with us.:thumbsup:
 

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Contractors Saw Dust Collection

Norman, thankyou for the welcome to the forum. I'm glad I could be of some help to you in achieving a cleaner and healthier working enviroment. It's allways nice to know when someone apreciates my efforts. Thanks again.
 

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dust collection and ventilation

FWIW -

Woodshop dust collection has had gallons of ink spilled in discussions.

Suggested reading - Bill Pentz's website www.billpentz.com. Zandor's (I can neither remember nor spell his last name) book on woodshop dust collection.

critical concepts and ideas - the chips one normally can sweep up using a broom and dustpan are not a hazard to one's health. The health hazards come from very fine dust.

Air movement depends on friction, turbulence, and pressure differences. The greater the friction, the less air movement. Round and smooth in more efficient than rectangular and rough. The greater the turbulence, the less air movement. Trees make great windbreaks. The greater the pressure differences between two locations, the greater the air movement. Compressed air is great for dusting out corners. Preserving pressure differences (eliminating leaks), reducing turbulence (straight runs, gradual turns), and reducing friction (smooth walled ducting and flex) combine to make the most effective use of one's dust collection dollar.

Bags do not filter the very fine dust effectively, because they have insufficient surface area to do so. Cartridge filters mated to the volume of air being moved can be effective, but the chips need to be separated out of the airstream first. Appropriate cyclone separator design and building are the most effective way to do that. Refer to cyclone design at bill pentz's site, and clear-vue cyclones www.clearvuecyclones.com.

The better the cylone design, the less friction and turbulence, the more efficient the system. Cyclones in which the inlet is angled to the same inclination as the deflector ramp have less turbulence than those in which the deflector ramp has to re-direct the airstream downward. Cyclones in which the inlet leads to the centerline of the upper cylinder have less turbulence than those in which the inlet stops at the cylinder wall. The upper cylinder height is dependent upon its diameter, and the angle of inclination of the ramp. Cone height is dependent upon cylinder diameter, with two natural "break points" at which the airstream easily turns around and goes up, leaving all but the finest dust behind. The smallest ratio of cylinder diameter to cone height should be 1:1.65. the second "break point" comes at 1:3.

Duct sizing for the volume of air to be moved is important. A small duct will carry only a small volume of air. If one works with MDF on a routine basis, one needs to move a sufficient volume of air to capture the dust before it gets out into the shop. That volume must also be moving quickly (~4000 fpm) enough that the chips are kept entrained in the air stream until separation. If the chips fall out in the ductwork, piling and plugging - dangerous situations - ensue.

Air movement depends upon the size of the impeller, and the ductwork leading to the impeller. Four impeller designs are, in order of decreasing efficiency, Airfoil, Backward Curved, Backward Inclined, and Straight. Most hobbyiest impellers have straight blades, because such impellers are the easiest and least expensive to manufacture. A three hp motor driving a 15 inch backward curved impeller can effectively move 800 cfm through six-inch ductwork that is smooth inside. In order to move that 800 cfm, however, the inlets must be sized for the ductwork. There is no way a 5 inch inlet is going to allow the passage of 800 cfm. A 4 inch inlet restricts the airflow even more.

allen norris
 

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The shop-vac is gonna have to do until I can afford a $300 system. Like I said, it's gotta be better than nothing at all.
Rob,
Why don't you take a look at one of those 1 hp Delta units or even one of those small portable dust collectors for $90 that HF sells.
I have to agree with others when they say that a Shop Vac will not move enough air to collect the dust from cutting MDF. That stuff flies around even with a good dust collector on the saw.
But, if you want to try to use a Vac, I'd recommend blocking off all openings in your saw. This includes the back, under the saw table etc.
A DC uses air movement to collect the dust, where as a vacuum system sucks up the dust so you only want to pull air from the source of the dust, ie the blade area.
 

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Contractors Saw Dust Collection

Allenn, I will agree with you that a canister filter is better than a bag at filtering air, unfortunatly at this time I can't afford a canister, so for now, along with low micron bags installed on the DC I have a air filtration unit hung from the cieling, plus I use a AO Safety woodworker's respirator which I think everyone should use regardless of what type of dust collection system you have. It's pretty tough, if not impossible to get all of the dust on every piece of machinery, but I will assure you that the setup I have with a 2 hp dust collector and a 4" port on the saw works plenty well.
 

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Woodchuck1957, check out wynnenv.com. Their series 35A cartridge filters are $95 for the paper and $136 for the cotton poly filters plus $9 for a set of 4 plastic chip bags (which replaces the bottom cloth bag on your unit).
I added their pleated paper filter to my Jet DC1100 for sub micron dust cleaning
 

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Contractors Saw Dust Collection

Ramon, one question I have about the pleated cartridge filters is, how often do they need to be replaced ? I know thats a tough question to ask considering every shop is different, but over several years I could see it geting really expensive.
 

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woodchuck1957, I was told by Wynn Environmental that the paper filters should be good for 3 years+ with hobbyist use. Clean them by blowing on the outside of the filter with a leaf blower or other compressed air source so that the caked on dust falls into the plastic bag below. The cotton poly filters last longer, but I don't remember how long. Give them a call and ask.
 

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Ramon, I did do some searching on the internet and noticed some complaints from people that when they were doing heavy sanding such as useing a edge sander, surface sander, etc. that the cartridges pluged up and lowered the CFM, so they were blowing out ( cleaning ) the cartridges more often than bags. I think the general consenses from the people that were haveing this problem feel that the bags were less maintenance. Now to add to all the confusion, I just recieved a e:mail from Wynn Environmental, Dick Wynn says that for the Grizzly G1029 that I have, the 35A100SBOL filter is popular with those who do a lot of sanding or MDF work because they can be cleaned faster. The pleats are more open, the surface is more slippery and they are washable. I will have to think about all this, I'm considering going to a cyclone dust collector, thats a whole other subject. Not that the Grizzly isn't working good for me, I just may have a chance at geting a pretty good deal on a cyclone and would like to try one.
 
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