I'm looking for articles on improving dust collection on a contractor's table saw [mine's a Jet 10"]. I want to close up the "cabinet" and get more of the stuff that now just blows out the back.
I'm doing an upgrade to my Jet 1100cfm dust collector, adding a Super
Dust Deputy cyclone and exhaust filter, which should capture everything larger than 0.5 micron, approximately 99.5% of all the sawdust.
Gordon, I like the lower hopper shown in the pictures Derek linked to. The panels on the rear of the saw I am not sure about. I would find it a PITA to change them and would tend to forget and have the saw bump into them when I tried moving the blade angle without changing them first.
Mine is an older Delta 10" contractors saw, very similar to the Jet. I spent a lot of time studying it and what I came up with May be complicated to make but simple to use and gets the vast majority of the dust.
It's a "box" or rectangular duct. That comes up from the bottom and encloses the blade. Its about 2" by 12" and angles down sharply on the left side to allow the blade to tilt. There is a transition called an end boot on the bottom that converts it to 4" round and it comes out the front to a blast gate. It rides on the trunnion in the place where there used to be a little half chute from the manufacturer. There is a piece of sheet metal that sits on the angles top to close it in.
This setup does a number of things for me. The blade is almost completely enclosed under the table and it gets the vast majority of the sawdust. The blast gate is on the front of the saw near the switch, easy to access and it turns on the DC when I open the gate. (Long Ranger with micro switch.) And it allows me to angle the blade without fiddling with anything else.
I don't have an over the blade pickup or blade guard above the table (shame on me), but I could. I have a tiny shop and can't bring myself to add anymore "clutter". When the DC is on there is a noticeable downdraft and very little comes off the top except when making a skimming cut down the edge of a board.
It took me two tries to get this down to my satisfaction. There is an angle in the box or duct that allows the blade to tilt fully without it crashing into the under side of the top or leg. I use a piece of inner tube as a connector to allow for some flexibility. I like it a lot, but if I were to do it again I might try the hopper.
But, I would make the hopper slope to the front so the blast gate could be in the front. To close in the rear I would look at using the "hula skirt" brushes you see on tractor trailers. I think the brushes would allow for some air flow inward and block most of the dust and yet allow the saw to tilt without having to rearrange panels. Or maybe make some panels that ride with the blade and sill cover the back of the saw. Or maybe some fabric. Use rare earth magnets to stick them on.
I wish I had a high speed camera to show me what is really going on under there.
Huge air flow helps.
Catching 99.5% of the dust may not be very good. If you filter passes the very fine stuff, that's the part that kills you. The sawdust you can see that lands on the floor almost immediately won't hurt you, you are not breathing it. Three suggestions: Move the DC outside the shop, outdoors where the fines will blow away. Use an Ambient Air Cleaner, Wear Personal Protective gear.
Go to Bill Pentz site for more than you ever wanted to know.
Gordon, just remember, you do not want to fully enclose the saw, you have to get air in from somewhere to feed the dust collector. I have a Delta Contractors table saw that I built a more efficient dust hood for under the saw out of sheet metal. It should fit your JET also. I closed off the gap between the cast iron top and the cabinet with closed cell foam, and blocked off the back of the blade4 also with sheet metal, that follows the blade when tilting it. And partially blocked off the back with sheet metal also. As you may have guessed I invested in some sheet metal machinery and tools to be able to do this type of work.
When I purchased a dust collection system over 15 years ago I spent some time studying and trying to close up the gaps in my Powermatic Artisan contractor saw. A sliding panel in the back to fit around two bars (which left gaps in the slots) and a panel screwed on the bottom. There are still openings around the adjustment wheels. It captures some of the sawdust by misses enough that I seldom bother to turn on the dust collector when using the saw. One of the reasons I'd love to upgrade to a SawStop cabinet saw.
Don, I can think of more practical things to do with my money then to spend a uneccesary amount of money on a industrial duty cabinet table saw for a hobby shop that generates very little to no money. There is nothing wrong with a good commercial duty Contractor's table saw, and regardless of what some of you say good and efficient dust collection can be had with a Contractor's saw.