tg

"tor"

24/12/2005 6:06 AM

making a downdraft table... questions.

Hi,

I am building a combo work bench/downdraft table. I have some
questions. I am working off of the design that rockler sells as a kit.
(20" x 40").

http://www.rockler.com/findit.cfm?page=6564&cookietest=1

I was going to just use two 20" square house fans in a blowers stead. I
have had some success with a ceiling air filter made with a house fan
and some furnace filter. Please keep in mind, I am not looking to suck
the hair off my body, just catch some of the dust.

questions:

1) The Rockler motor looks to have some cool impeller of some kind. Is
this impeller something like what a vacuum has? Are they sold?

2) could a fan blowing from above, down onto the table help?

3) What is a good material for the surface? (I was going to drill out
perfed melamine)

4) I have a 1.5 horse vacuum nearby, I can do better with some fans,
can't I?

Thanks!!

Tor


This topic has 6 replies

Ww

"WillR"

in reply to "tor" on 24/12/2005 6:06 AM

24/12/2005 7:57 AM


Amused wrote:
> "tor" <[email protected]> wrote in message
> news:[email protected]...
> > Hi,
> >
> > I am building a combo work bench/downdraft table. I have some
> > questions. I am working off of the design that rockler sells as a kit.
> > (20" x 40").
> >
> > http://www.rockler.com/findit.cfm?page=6564&cookietest=1
> >
> > I was going to just use two 20" square house fans in a blowers stead. I
> > have had some success with a ceiling air filter made with a house fan
> > and some furnace filter. Please keep in mind, I am not looking to suck
> > the hair off my body, just catch some of the dust.
> >
> > questions:
> >
> > 1) The Rockler motor looks to have some cool impeller of some kind. Is
> > this impeller something like what a vacuum has? Are they sold?
> >
> > 2) could a fan blowing from above, down onto the table help?
> >
> > 3) What is a good material for the surface? (I was going to drill out
> > perfed melamine)
> >
> > 4) I have a 1.5 horse vacuum nearby, I can do better with some fans,
> > can't I?
> >
> > Thanks!!
> >
> > Tor
> >
>
> I have a Ryobi air flotation/down draft tabletop that I bought at a garage
> sale. Let me see if I can find it on Google. (No luck on finding a
> picture) It was actually designed to fit on one of their table saws. (BT
> 3000, I think) The table was new, in the box, but it only came with two
> legs. Apparently the other side connected to the table saw in some manner.
> It was no problem to create a couple of legs to make a standalone table.
> It's really pretty slick. The top is about two feet by four feet, with
> small holes every square inch. In the middle of the table is a slide
> mechanism that acts as a gate. The table is made to install a shop-vac,
> under it, but with a converter, (to take it from two and half to four
> inches), I was able to connect it to my dust collector with no problem.
>
> BTW, I ran out of room in my shop, and ended up sacrificing the table. I
> saved the top, with vague plans to possible adapt it as an extension to my
> Griz table saw....

check http://bt3central.com

There may be a picture there.
http://bt3central.com/

I use one on my Ryobi -- it is OK.

willr
http://woodwork.pmccl.com

Ss

Scorp

in reply to "tor" on 24/12/2005 6:06 AM

26/12/2005 11:43 PM

On 24 Dec 2005 06:06:35 -0800, "tor" <[email protected]> wrote:

>I am building a combo work bench/downdraft table.
>I was going to just use two 20" square house fans in a blowers stead. I
>have had some success with a ceiling air filter made with a house fan
>and some furnace filter. Please keep in mind, I am not looking to suck
>the hair off my body, just catch some of the dust.

I'd make mine with filters inline, your going to want to use a very
fine filter for sanding dust, having one or two coarser ones before
hand will save some money. Fans wouldn't do this, try a furnace fan
or maybe spring for a larger dust collecter and pipe it to any box
with holes you decide.

There's a Woodsmith article (Vol 15, Feb 93) with a good design
similar to your link. I even scrounged a nice furnice fan with no
motor for free, however I never made it as I just made a 4 x 8' box
with 1/4" pegboard on one side, 1/2 hardboard on the other, 2x6 frame
with holes to each chamber. Sit's on a couple sawhorses. I have a 4
bag 2Hp DC connected. This is also my outfeed table for my tablesaw
and bandsaw.
I block off areas if I'm doing smaller work.
I don't have access to clean it out however and it weighs a ton, make
a nice fire when it's time to upgrade.

>questions:

>1) The Rockler motor looks to have some cool impeller of some kind. Is
>this impeller something like what a vacuum has? Are they sold?

Don't know, want a furnace fan :)

>2) could a fan blowing from above, down onto the table help?

I wouldn't, you want all the air flow towards the table but too much
will blow it away.

>3) What is a good material for the surface? (I was going to drill out
>perfed melamine)

1/4 inch pegboard, glue up multiples for whatever thickness you'd
like.

>4) I have a 1.5 horse vacuum nearby, I can do better with some fans,
>can't I?

Vac's don't do volume well and fans don't like restricted flow (they
don't suck) or too fine/too many/clogged filters.

Good luck.

--------------------
Steve Jensen
Abbotsford B.C.
[email protected] chopping out the mortise.
BBS'ing since 1982 at 300 bps.
Surfing along at 19200 bps since 95.
WW'ing since 1985
LV Cust #4114

Nothing catchy to say, well maybe.....
WAKE UP - There are no GODs you fools!

GG

"George"

in reply to "tor" on 24/12/2005 6:06 AM

24/12/2005 12:07 PM


"tor" <[email protected]> wrote in message
news:[email protected]...
> 3) What is a good material for the surface? (I was going to drill out
> perfed melamine)
>

1/4" tempered pegboard over a lattice of 1x2.

AA

"Amused"

in reply to "tor" on 24/12/2005 6:06 AM

24/12/2005 10:09 AM


"WillR" <[email protected]> wrote in message
news:[email protected]...
>
> Amused wrote:
>> "tor" <[email protected]> wrote in message
>> news:[email protected]...
>> > Hi,
>> >
>> > I am building a combo work bench/downdraft table. I have some
>> > questions. I am working off of the design that rockler sells as a kit.
>> > (20" x 40").
>> >
>> > http://www.rockler.com/findit.cfm?page=6564&cookietest=1
>> >
>> > I was going to just use two 20" square house fans in a blowers stead. I
>> > have had some success with a ceiling air filter made with a house fan
>> > and some furnace filter. Please keep in mind, I am not looking to suck
>> > the hair off my body, just catch some of the dust.
>> >
>> > questions:
>> >
>> > 1) The Rockler motor looks to have some cool impeller of some kind. Is
>> > this impeller something like what a vacuum has? Are they sold?
>> >
>> > 2) could a fan blowing from above, down onto the table help?
>> >
>> > 3) What is a good material for the surface? (I was going to drill out
>> > perfed melamine)
>> >
>> > 4) I have a 1.5 horse vacuum nearby, I can do better with some fans,
>> > can't I?
>> >
>> > Thanks!!
>> >
>> > Tor
>> >
>>
>> I have a Ryobi air flotation/down draft tabletop that I bought at a
>> garage
>> sale. Let me see if I can find it on Google. (No luck on finding a
>> picture) It was actually designed to fit on one of their table saws. (BT
>> 3000, I think) The table was new, in the box, but it only came with two
>> legs. Apparently the other side connected to the table saw in some
>> manner.
>> It was no problem to create a couple of legs to make a standalone table.
>> It's really pretty slick. The top is about two feet by four feet, with
>> small holes every square inch. In the middle of the table is a slide
>> mechanism that acts as a gate. The table is made to install a shop-vac,
>> under it, but with a converter, (to take it from two and half to four
>> inches), I was able to connect it to my dust collector with no problem.
>>
>> BTW, I ran out of room in my shop, and ended up sacrificing the table. I
>> saved the top, with vague plans to possible adapt it as an extension to
>> my
>> Griz table saw....
>
> check http://bt3central.com
>
> There may be a picture there.
> http://bt3central.com/
>
> I use one on my Ryobi -- it is OK.
>
> willr
> http://woodwork.pmccl.com
>

Does your table have a slide mechanism underneath, that allows you to swing
the hose connection back and forth, thus blocking and unblocking suction?

It's actually pretty simple design, but works well.

James..

AA

"Amused"

in reply to "tor" on 24/12/2005 6:06 AM

24/12/2005 8:47 AM


"tor" <[email protected]> wrote in message
news:[email protected]...
> Hi,
>
> I am building a combo work bench/downdraft table. I have some
> questions. I am working off of the design that rockler sells as a kit.
> (20" x 40").
>
> http://www.rockler.com/findit.cfm?page=6564&cookietest=1
>
> I was going to just use two 20" square house fans in a blowers stead. I
> have had some success with a ceiling air filter made with a house fan
> and some furnace filter. Please keep in mind, I am not looking to suck
> the hair off my body, just catch some of the dust.
>
> questions:
>
> 1) The Rockler motor looks to have some cool impeller of some kind. Is
> this impeller something like what a vacuum has? Are they sold?
>
> 2) could a fan blowing from above, down onto the table help?
>
> 3) What is a good material for the surface? (I was going to drill out
> perfed melamine)
>
> 4) I have a 1.5 horse vacuum nearby, I can do better with some fans,
> can't I?
>
> Thanks!!
>
> Tor
>

I have a Ryobi air flotation/down draft tabletop that I bought at a garage
sale. Let me see if I can find it on Google. (No luck on finding a
picture) It was actually designed to fit on one of their table saws. (BT
3000, I think) The table was new, in the box, but it only came with two
legs. Apparently the other side connected to the table saw in some manner.
It was no problem to create a couple of legs to make a standalone table.
It's really pretty slick. The top is about two feet by four feet, with
small holes every square inch. In the middle of the table is a slide
mechanism that acts as a gate. The table is made to install a shop-vac,
under it, but with a converter, (to take it from two and half to four
inches), I was able to connect it to my dust collector with no problem.

BTW, I ran out of room in my shop, and ended up sacrificing the table. I
saved the top, with vague plans to possible adapt it as an extension to my
Griz table saw....


Rd

Robatoy

in reply to "tor" on 24/12/2005 6:06 AM

24/12/2005 11:20 AM

In article <[email protected]>,
"tor" <[email protected]> wrote:
[snipped for brevity]
>
> 1) The Rockler motor looks to have some cool impeller of some kind. Is
> this impeller something like what a vacuum has? Are they sold?
>
> 2) could a fan blowing from above, down onto the table help?

Absolutely not. It is the 'air-make-up' that moves the dust to wards the
source of negative draft.
>
> 3) What is a good material for the surface? (I was going to drill out
> perfed melamine)
Hardboard..perforated hardboard 1/4" thick. Cheap as dirt.
I think those rubber floormats, anti-fatigue honeycomb style, may work
really well when used upside-down. All those little rubber titties
holding up the work, non-skid, and all those big holes moving air...
yup.. that stuff would work great... just put it on a lattice frame.
>
> 4) I have a 1.5 horse vacuum nearby, I can do better with some fans,
> can't I?

Yes.. the need is for volume..you want to move LOTS of air.
Box-style window fans with furnace filters work okay... a couple of
furnace blowers work GREAT!
>
> Thanks!!
>
> Tor


You’ve reached the end of replies