Downdraft Sanding Table/Cabinet?

[Roger Eihausen]

Picture 050 (665 x 499).jpg
here is one I built years ago

[richard poitras]

Have you looked on Craigslist lately? I see them now and then for reasonable prices. I just picked up a Denray down draft table. Model # 2634B that sells new for about $2000 for $250.00.

Richard

[Josiah Bartlett]

John wrote: "....The question is partly of horsepower. A DC sucking 900 CFM is probably a 2 hp motor pulling about 8-10 amps of 220v juice. A furnace fan is 1/3 horse draws an amp of 110 and can push 1500 CFM or more...."
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What am I missing here? Why don't we use furnace motors/squirrelcages to pull through our cyclones? Does the fine dust wipe out the squirrel cage efficiency quickly if it's before the filter?

The squirrel cage blower can only move that much CFM if it doesn't have any restriction on the input or output, and squirrel cages won't be able to pull much of a vacuum. Dust collector blowers are designed to be able to suck all that air through a 6" hose and out through a filter.

[hank dekeyser]

I "threw one together" last week that connects to my cyclone. It doesn't work all that great so I revamped it to use my summer blower (squirrel cage) and it is quite an improvement. Now if only I had built it big enough the first time. I pretty much just made a criss-cross of 11x2's I had left over and put some sides on it w/ a bottom. problem was, the scraps I had dictated the size I made. Oh well, keep in mind to be sure whatever yo ubuild that it is larger than the largest panel you plan on sanding on it. I didnt bother w/ drilling holes in a sheet simply because I figured the criss-cross would make more sense and allow better airflow. I use anti slip / sanding pad stuff on it and have a few scrap pieces of 1/4" ply I use to "shorten" the table / block off the excess openings depending on size of piece I'm sanding. After all you only need to draw air on the perimeter of the workpiece for it to be effective, and all the holes in the middle are pretty useless since the workpiece covers them anyway. Dug an old DC bag out of the trash and made my own pleated filter. So far so good BUT it will be upgraded when I find the time. I'll be sure to post pics when it happens

Couple things I thought of already

table size
filter accesibility
speed controller (I have a 4 speed motor on mine)
larger bottom to allow a larger filter
Difuser/collector, so ALL the dust doesnt have to go through the filter
output baffle/ difuser

[Mike Cruz]

Kevin, do you mean a unit like this? I'm actually selling mine. You're a little far away, though...