Downdraft box

[Dadio]

Here is a downdraft box I just completed today.

[John Morris]

Now that is cool! What powers the vac Herb?

[Stick486]

Just now, John Morris said:

Now that is cool! What powers the vac Herb?

probably electricity...

[John Morris]

Just now, Stick486 said:

probably electricity...

Let me re-phrase that, what vac system are you using for the table?

Thanks Stick.

[Stick486]

Herb...

will you be putting hardware cloth uder those hole to prevent small part loss???

[John Morris]

1 minute ago, Stick486 said:

Herb...

will you be putting hardware cloth uder those hole to prevent small part loss???

Them some big holes, I was thinking that myself. Also, I know Herb knows what the heck he is doing, but, downdraft table hole sizes are very important, big holes may not pull as hard, as many smaller holes, kind of that whole CFM thing I don't know much about, just enough to get in trouble, so I am counting on Herb to have done his research for us.

[John Morris]

Just googled downdraft tables, they got some big holes too, not uncommon, my ignorance shining through, again.

[Stick486]

13 minutes ago, John Morris said:

Just googled downdraft tables, they got some big holes too, not uncommon, my ignorance shining through, again.

plan ''B''... egg crate light grids...

of course you reinforce them w/ a 1 by grid..

 

[Stick486]

an inside look...

 

25077-Down-Draft-Ezplan2.pdf

[smitty10101]

Just a rouge thought here

 

IF you had built it with flat bottom couldn't you then put dividers into the box to chock off the holes not being used during that particular sanding operation.

I understand the logic for the inclined bottom but the community seems to be questioning the ability to effectively pull air

 

@Stick486  I like the idea of the egg crate --quick & easy.

 

putting cloth under the holes---- how about a furnace filter or a loose filter type mesh?

Edited September 4, 2018 by smitty10101
add'l wording

[Stick486]

not cloth..

hardware fabric...

and you want the dust to go to the collector.. not filter it...

 

 

 

 

Edited September 4, 2018 by Stick486

[HandyDan]

Put one of these in line to the shop vac.  You'll save time and money on changing and buying filters.  They work very well.

 

[lew]

Nicely done!

 

I always seem to forget to use mine.

[Grandpadave52]

On 9/3/2018 at 11:09 PM, Dadio said:

Here is a downdraft box I just completed today.

Looks great Herb...few ??'s for you

(1) Dimensions... LxWxH

(2) Appears your grid is in 3 pieces? If so, any particular reason? Are they each removable?

(3) Any type seal (e.g. foam, silicone) between the grids and the frame?

(4) I know you're going to make some kind of handles for this, right?

(5) Are there other questions I should have?

[steamshovel]

I made mine out of pegboard and hooked up to my dust collector. It works great so far.

 

Preston

[PeteM]

On ‎9‎/‎3‎/‎2018 at 8:36 PM, John Morris said:

downdraft table hole sizes are very important, big holes may not pull as hard, as many smaller holes, kind of that whole CFM thing

Small holes (like 1/4") "reach out" from the surface IF YOU HAVE the power (usually, at least a real dust collector). If you put enough suction (large DC), it can even reach horizontally 12--18" (design was to capture anthrax dust).   Large holes (Dadio's) take advantage of gravity, making a dust motel (dust checks in, not out), probably capturing anything that gets within a couple inches, lighter stuff maybe a couple more.  The holes in Dadio's design make it easy to lift out the deck, so retrieval shouldn't be a problem.  I'd put 1/4" hardware cloth over the exhaust duct port for convenience.

[Stick486]

16 minutes ago, PeteM said:

I'd put 1/4" hardware cloth over the exhaust duct port for convenience

put on the bottom side of the deck makes part re-trivial easier and less and a blockage would be less likely to happen......

small holes in the deck tend to whistle.. louder the smaller the holes and the more CFM you have..

small holes restrict the CFM...

[lew]

The way I made mine-

 

 

[Dadio]

After reading this: http://billpentz.com/woodworking/cyclone/downdraft.cfm 

 

I am not sure it will even work.

 

12 hours ago, Grandpadave52 said:

 

(1) Dimensions... LxWxH

(2) Appears your grid is in 3 pieces? If so, any particular reason? Are they each removable?

(3) Any type seal (e.g. foam, silicone) between the grids and the frame?

(4) I know you're going to make some kind of handles for this, right?

(5) Are there other questions I should have?

I used the Rockler pdf.

25077-Down-Draft-Ezplan2.pdf

 

1. 27X17X6"

2.Yes

3. No

4.yes, I bought some yesterday.

 

No Hardware Clothe.  What small parts are supposed to be able to fall into the box? this is for ROS sanding things larger than the holes. And since it is not made for cleaning the shop air en mass just for creating a negative pressure around a small area where I am sanding, and according to the article above will not work anyway, I may be able to cover part of the top,depending on the size of my piece to adjust the air flow. Thanks for all the comments,and suggestions, I should have done more research before I built this.

 

Herb

 

 

[Stick486]

1 hour ago, lew said:

The way I made mine-

that is some 1st rate thought out and follow through lew...

Edited September 5, 2018 by Stick486