I currently us two portable collectors -- shop-vacs with dust separator (conical ones like Dust Deputy) with 5 gal. bucket etc. One is 2-1/2" and the other is 1-1/4". These is not very effective for the grinders, table saw and mitre saw. As a birthday gift, I received a 1 hp - 600 CFM dust collector (Craftex CX415 from Busy Bee). In total, I have three grinders, two band saws, a buffing station, a mitre saw and a table saw. Some are 4" dust ports, some are 2-1/2" and there's a few portable tools that have 1-1/4" ports. I will need a bunch of blast gates, pipe, hose and fitting, clamps and so on. I am still debating over leaving my portable dust separator/shop-vac setups for the smaller equipment. I was wondering if you seasoned dust collectors have any tips before I start planning plumbing. Like pipe elevation, where to locate blast gates, where to use pipe vs. hose. What to line the hose with for fire resistance, static discharge wire...etc. Any comments appreciated. Dan
Dust collection is on thing and trying to collect grinder dust and SPARKS is another thing. I have had two fires in Shop Vacs from trying to collect dust and sparks off my grinder. Once a shop vac starts on fire it is like a big forge with all the air moving through it. So I took a 5 gallon metal pail and put an inlet and outlet on it with a baffle inside the pail and hook it up to the grinder and a RIDGID vac up to the metal pail. The sparks and larges fines stay in the metal pail and the fine dust ends up in the Ridgid vac, it works quit well. I no longer use SHOP VACS as the only last a year and the motor burns out and they suck everything into a bag. The Ridgid vacs filters the air leaving the vac and are a lot less prone to starting on fire.
Great tips. Thanks Cal. I've had steel fires under the belt. A mound of filings + fresh sparks + wind from the belt and steel ignites and burns pretty well. I use cyclonic dust separators ahead of both my vacs and the vacs really never see any dust. Four gallons of sawdust in the bucket and less than a tablespoon is in the vac. Brilliant they are, but a system as a whole is bulky and clumsy to move around. In your metal bucket, does the baffle fit vertically between the inlet and outlet? Something like this? Was also thinking about using some 4" duct boots like this on the belt grinders: with a length of metal ducting and two elbows before transitioning to the dust collector hose. Kind of like a P trap. These boots are 3.5" x 10" so should fit well under the disc grinder too. Thinking to use neodymium magnets to hold in place. Dan
This is Franken-Vac the first. About as homemade looking as it can get and still running strong after 12 years of faithful service. The dust separation cone I made from 20 thou aluminum sheet, plywood and foil tape. This creates a vortex that separates the incoming dust from the air and the dust drops to the bucket below. I'd venture to guess that over 99% of the incoming dust and debris ends up in the bucket, and not in the vac. The vac itself is an old Genie. I'm not even sure Genie makes vacuums anymore, but for now Frankie is still alive. Dan
I’ve been looking into this for a while. And I am thinking about tackling it like a spray booth, primarily a down draft spay booth as my grinding room is separate from the rest of the shop. I’m going to bring fresh air in from outside to push down into the room and have duct fans and ducting, one set of ducts for when I am grinding steel, and one set for wood and composite handle grinding, going to respective and separate collection bins. All the ducting will be grounded into the earth outside. I have to change the room itself around too. I am now regretting setting up benches in the room, because benches collect dust...and tools, because I’m terrible for not putting back where it’s supposed to be lol. So the plan is to have everything on pedestals instead, so minimum surface area for dust to collect. Not a small endeavour, so nothing I’ll be posting on anytime soon. These spark traps are interesting too, but me thinks they are expensive https://www.nederman.com/en/product...anized/inline-spark-trap/c-24/c-1692/p-420887 https://www.ductingsystems.com/nordfab-parts-spark-trap.html Smock Knives has the Nordfab one installed here in his setup
Just found this spark trap too https://www.mississaugahardware.com/product/festool-484733-spark-trap A bit more reasonable and it does mention ‘Metal’ though maybe the diameter is too small?
I am with you there Griff. Horizontal surfaces are the worst. I am slowly converting all open shelves stock to storage containers with lids, but reducing dust escaping from the source in the start of the plan. For a spark arrester, I think it would be reasonable to make a labyrinth type system with water to stop sparks like Cal was referring or like what Smock has under his grinder. Not sure if the plastic storage container is the best idea, but at least one can see when it's getting full. Questions I have are around system layout. Is it better go high with a main line and drop down to the machinery? It seems counter intuitive to have the dust fighting gravity on the way back to the collector. Maybe a better plan would be to run on the outer walls and keep the main line about level with the inlet to the collector. Is there a benefit to having the blast gates close to the main line or up close to the machinery is ok? I know @Kevin Cox has a pretty well setup dust collection system in his shop. Maybe he could share some of his expertise. Dan
Awesome Cal. Great ideas there. I think I will hunt down a 5 gallon metal can and make something like yours for the grinder. Elegant design. I take it the purpose of the baffling is to create turbulence and disrupt the flow enough to cause the heavier particles to drop in the bucket, while the lighter particles moves along to the vac. The outlet being higher than the inlet means the particles have to overcome gravity too. Is that a chunk of steel in there for ballast? By looking at the bottom of the bucket, I'd say it works! The squirrel cage blower and filter is good idea to pick up stray airborne dust. Is the motor wired to draw air into the filter then over the motor and out? This would sort of suck the filter media into place when running. This is what I need after running the table saw. My saw is an old 1976 Rockwell Beaver that is partly boxed-in at the bottom with plywood. The motor and belt hang out the back of the saw and it's not easy to seal around them. I guess back in those days, dust wasn't a problem and simply swept up at the end of the shift. Must be why my Dad (retired cabinet maker) can be heard clearing his throat all the time! I could throw lots of suction at it but reckon there's always going to be some dust escaping. Could run the filter fan for a while after sawing. Thanks again for the ideas! Dan
So in the box of dust collection accessories I bought on Amazon I found this diagram. Note the blast gates are located close to the main line. Last night I started putting things together. I don't want to make holes in the overhead door, so I strapped some 1-1/2" ABS and made some Z brackets to set the hose in. In the event I need to open the door the whole thing can un-hook. Still waiting for some more wyes and a 4" to 2.5" reducer. Next step is to get my metal boots and ducting, then setup some spark arresters. Home Depot here we come. Dan
Rabbit hole alert. A young aerospace engineering I work with has got me enthused about designing a centrifugal spark arrester. The idea is one creates a cone with vanes on it that when placed in the air flow, causes the air to spin. Heavier particles are slung to the outside, while the air continues to move through the line. The whole thing shouldn't be much bigger than a breadbox. Of course it will have to be made from bits & pieces from the HVAC department at the hardware store. This should prove to be a learning experience. Wish me luck. Dan
Oh great you can make them! Hopefully construction costs come in under the $400 (u.s) for the 4” diameter entry level Nederman! Looking forward to seeing this Dan *thumb up* Also like the benches the grinders are set upon, much smaller footprint than benches.
Have to be careful with these young bucks. All theory and no practice. LOL I did make a prototype impeller last night out of a dollar store oven pan and some foil tape. Once the form is checked out I'll probably stiffen it up with fibreglass. If I need to double the vanes that can be done too. The idea is that this is supposed to encourage the air to start rotating inside the reducer. At the same time the area will be expanding and pressure dropping accordingly. The next step is a larger diameter sleeve, say 8" which is capped at the vac end and a 4" line continues on to the vacuum. If any fluid dynamics people have any suggestions please chime in. I am an electrical guy and this is a bit out of my league. In the meantime, I have got the disc grinder connection done. I don't normally make much in the way of sparks on this guy, but metalized it just in case. The boot (scoop) is 3-1/2" x 10" with a 4" diameter connector. Held on the grinder frame with three neodymium disc magnets so I can easily remove and suck out the bottom of the hose. Be ye warned. These aluminum hoses will kink by just looking at them. Treat them with kid gloves and they look great. More coming soon. Dan
Some tweaks and another batch of shooting sparks at the thing. After some solid grinding, I collected about a tablespoon of grit from withing the arrester. I am thinking about how to add some kind of trap with a clean-out. Dan
I did some tests with an anemometer to see how much the spark arrester drops the air velocity. The readings were taken from a point about 25' down the vacuum hose from the dust collector. It looks like about 15%, which I think is pretty respectable considering the effectiveness of unit. Dan
I don't have a dust collector but have been researching them lately. Everyone recommends upgrading the bag to a Wynn environmental canister unit. They're supposed to increase the air flow about 30% while also allowing much finer dust collection. They are bloody expensive though. There's a whack of air flow tests on YouTube. Once I get my shop fixed renovated a decent dust collection system will be the first new tool for the wood shop.
