Downdraft Table Design question
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I’m about to move my “new” downdraft table into the shop (bought it at that auction a few weeks ago, just finding room for it). In order to fit it in, I’m gonna have to shuffle some stuff around, get rid of a small cabinet or two. Still, I’m looking at all that space inside the table and wanting to use some of it!
—->So, the question is, how many cubic feet of actual space do I need inside there? The interior dimensions of the table are about 23″W x 39″L x 29″H. It was dark when I was looking in there, so I didn’t get any info off of the blower motor yet.
What I’m thinking about doing is making a door in the end opposite the blower outlet, and storing my little Porter Cable pancake compressor in there. Or, maybe making some very shallow drawers in the bottom to keep stuff I don’t use very often.
forestgirl — you can take the girl out of the forest, but you can’t take the forest out of the girl 😉
Another proud member of the “I Rocked With ToolDoc Club” …. :>)
Replies
Is your downdraft table a home built or manufactured affair? Would you set it up with your DC or a shop vac? What are the dimensions of the table?
I don't know anything about this kind of thing, but I would like to rig up something for my own shop. I would guess that you want to minimize the space directly underneath the table -- say 5-6 inches, to maximize suction. Does that seem right?
Edited 7/23/2004 2:51 am ET by nikkiwood
This is a big sucker (well, blower, really), home-built by the Guy Who Had Everything. It's 37.5" high, 48"L and 20-something wide (senior moment, 26" maybe). He hand-drilled all the holes in the top, an chamfered each hole with a countersink!
The blower is a Dayton 4-speed with a 9.5" wheel. In the pics below, you'll see he built in the blower switch, and a 2-receptacle outlet with an on/off switch. This ain't your mamma's portable down-draft table, LOL!
I'll be able to use it as an outfeed table for my tablesaw by making up a "top" to make it the same height as the saw. The top would also enable me to use it as a workbench of sorts.
PS: That's a shadow in the upper-left of #1. Cost was about $90, IIRC. Web tip on attachments: right-click, select "Open in New Window"
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Edited 7/23/2004 12:41 pm ET by forestgirl
Jamie..lord knows, I'm no expert at airflow, but looking at the "beastie" I reckon that you could get up to 50% of it's internal volume as useable storage space. If it hasn't already been done, you'd need to add a series of ramp shaped "venturi", starting from the farthest point from the intake side of the fan, gradually sloping lower as you get closer to the intake. These ramps would need to be sealed pretty well to make sure that the fan draws as much air as possible through the holes in the table as opposed to anywhere it pleases.Mike Wallace
Stay safe....Have fun
Jamie,
When I was researching building a downdraft table, the common design feature seemed to be a fairly shallow "funnel" shaped collection area with the 4" or 5" port located in the center. The funnel was usually plastic or slick sheet metal to aide in the material sliding towards the port. If your table is simply a big boxn using filters, then I would think it would be easy to modify to add the funnel and port and create storage under the table since only using the top 7 or 8 inches for the actual dust collection.
Doug
Jamie, My down draft table--48x30x36" high--is just a big box with the 1/2hp motor and the squirrelcage fan unit inside. All the filtration is at the top of the box so the air inside the box is all filtered and clean. The filters are a pair of 20x20 pleated with 20x20 furnace pre-filters.
I store lots of things inside the box. At any one time there will be some extra filters, a couple of old corded drills, a small bench mounted drill press, anything. It's a pretty good storage area. Putting things in the nooks and crannies will have little or no affect on the operation of the sanding dust collection.
Hey Forestgirl,
I built something like you have with 6 drawers in it. I have some internal shots of the fan cavity and dust shoots on my website. Here is the address of the page with the sanding bench.
http://www.superwoodworks.com/Projects/SandingBench.htm
If you have any questions just email me at the address link on my site
Garry
HEY! Gurl, what a steal? You gave me a good idea.
Why not use the available space to install a vacuum pump and make it able to hold small parts to rout or sand or laminate via glueups without clamps.
You might have to cover the existing holes with a sheet metal or formica plate using localized smaller holes???Steinmetz
That's an intriguing (sp?) idea, stein. A bit advanced for me at this point, but somethin' I'll sure keep in mind. What might I need to do besides seal off some of the holes....hmmmmm.......maybe replace the Masonite top with something more sturdy, or would the Masonite do OK, d'ya think?
One thing I've envisioned, but been shy about describing <g> is setting my miter saw up there, with a Hollywood Bowl type shroud around it, and the Shop Vac hooked up to the dust chute. Wonder how much %% dust I'd collect between the vac and the downdrafting?
Jeeze Louise it's hot over here today. OK, OK, I know 80+ degrees isn't all that hot, but we're not used to it! The days of my revelling in hot temps are long gone. Hubby and I are headed over to the Olympic Peninsula tomorrow to get away from the heat. The highs will be about the same, but the low at night should be 20 degrees cooler! Yes! We're staying at the "Hungry Bear Motel" so if I'm not back on-line Monday, you'll know who was selected for the entree, LOL!forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
F G, I saw a comercially built downdraft table just yesterday
Thinking it was a vacuum holddown device, I asked the Distrubutor (Who was using it as a display for use of air operated sanders.)
He clued me in that it was just a downdraft table and that he had not even heard of a vacuum hold down device before.
My son, (Who owns and runs a tool and die business,) thinks that the present system (Not unlike yours) would probably work as a holddown, if you'd lain a sheet of formica over the existing top and by drilling lots of smaller holes in a round circle at the center of the formica .
Lets say if this perforated section comprised 1/4 of the surface area, it would hold down workpieces without clamps or carpet tape ????
Also for gluing laminations or veneer you would throw a sheet of vinyl over the glued up work pieces covering the whole table and the vacuum created would apply even pressure to clamp it tightly till the glue dried.
Something like those ads on late night TV, where the 'Huckster' vacuum seals hamburger patties or blankets or dirty laundry
Maybe drain your old oil through the car's dipstick hole???? Don't laugh, I've done it with an old pressure cooker hooked to my compressor's intake filter.. Works honest
Beats climbing under the old chevy in the rain or snow LOL LOL ED From CT.
Edited 7/23/2004 8:59 pm ET by steinmetz
Western Olympic pennisula is running in the 90's too. They are are having a Harley run here this weekend with an estimated 2000 riders in town.
2000 riders. Yikes!
The weather report said 80+ for the high, but 50-something degrees at night, which will be significantly cooler than here.
This will be the first time I've left the big collie behind. He's staying out at the stables with his Golden Retriever friend and his owner. Hope he does ok, sniff....forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
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