Down Draft Box

[Herb Stoops]

A while back I made a down Draft Box and posted it another place so I will post it again on this forum for those who are interested that didn't see it.
I made it out of 1/2" Medium Density Overlay plywood,MDO, that can be obtained from most lumberyards. It was originally designed for concrete forms and has a layer of resin coating one side or both sides.
The top side has holes in 3 removable panels for the air/dust to be drawn down into it,and be removed by the dust collector.
I drilled the holes larger than most commercial Down Draft Boxes to allow greater air flow. After trying several assorted type bits I found the best results were from a sharp 3/4"Paddle bit of all things. The top was drilled on the drill press from both sides to eliminate blowout on the bottom side. Then I beveled the holes with a chamfer bit in a router, and sanded the holes smooth on the Ridgid Oscillating spindle sander. The top panels I screwed down to make them removable and counter sunk the holes with my new retracting countersink, which did a good job.
I found that one the first try at sanding I wasn't getting the air flow I desired. So I made removable sides for the box on 3 sides. This increased the available air flow 100% and worked like I wanted it to. It was somewhat noisy from the vibration of the sander on the material which was annoying, so I tried a small perforated black foam mat under the work piece. That did quiet it down a lot and didn't interfere with airflow.
Here are pictures of the build.
Herb

[Stick486]

most excellent HErb!!!!

[Stick486]

other plans and some additional information...

Downdraft Table Plans.pdf

25077-Down-Draft-Ezplan2.pdf

[Herb Stoops]

I made a Rockler in a previous life, but made my own top,didn't buy theirs. The rubber grommets they use serve as a cushion to reduce noise. On that one I glued a perforated foam mat down totally over the whole top panels. It worked OK ,but was a PITA to cut all the holes in the mat, I needed a hole punch, but didn't have one that size. In my opinion they could use more holes there are a lot of void space between holes.
HErb

[Stick486]

Use an egg crate screen..
.

SCREEN.jpg

.
or one out of lattice...
.

lattice screen....jpg

[Herb Stoops]

Those two examples would make good Down Draft Table tops. The screening/hardware cloth needs to be of the rigid type so it doesn't sag, or have some support beneath it.

Herb

[Stick486]

The screening/hardware cloth needs to be of the rigid type so it doesn't sag,

that's not hardware cloth...
the grid from another angle...
they also come in diamond and honeycomb...
.

grid.jpg

[Jon]

I like that design, well done Herb. How does this preach compare to attaching a shop vac to the sander dust port? I have been relying on that approach and don't find that much dust about. The shop vac is equipped with a HEPA filter and a dust collection bag.

[Herb Stoops]

Jon what you do works too, I used to do that. But dragging the hose around attached to the sander,made my wrists hurt keeping the sander flat to the work and not tilting and digging in. That said I have seen where guys have an uprights attached to the bench with the hose draped over it to free up the drag. I feel the same way about a hose attached to a router or circular saw, I would rather put up with the chips than wrestle with the hose. But that is just me. It doesn't seem to bother a lot of folks.
Herb

[Cherryville Chuck]

Have you ever tried laying matting or something similar on the unused portion of the grate to see if that helps with suction?

[Herb Stoops]

That might cut down on the air flow, and since it works good I haven't tried to improve it

[Stick486]

That might cut down on the air flow, and since it works good I haven't tried to improve it

if it ain't broke...
don't fix it????

[DaninVan]

Or the corollary; 'If it ain't broke you just aren't trying.'

[KellyCraig]

My beast kicks butt because I not only added full sides and a back, I added a top. This forced all the air being taken into the system to be pulled in past me.

After adding the soft sides and top, efficiency climbed off the charts. Using an aggressive bit, which really throws the dust, I watch the debris thrown off the cut parallel to the ground, only to do an arcing 90 down into the table. I even router projects in my dust collection table.

It ain't purty, but it works.

Sanding Station-3.jpg

[Stick486]

EXCELLENT...

[RainMan]

Nice work Herb , and looks like it would meticulous as heck . You can’t put enough value on saving those lungs though . My friend is 82 ,and last year alll of the sudden he couldn’t breath . Turns out all those years of working as a heavy duty mechanic around those 200 ton trucks in the mind with diesel fumes did him in .
Of course they have better systems in place to limit how much you breath in fumes, but doesn’t help him now . But it does show you the importance of mitigating dust ect

[Herb Stoops]

Kelly,
As long as it does the job you want,that what counts.
Good job, more than one way to skin a cat. By confining the space around the top so the dust has to go one direction is the goal, on just a flat top the dust can get away and then fly in all directions.
Herb

[Cherryville Chuck]

My beast kicks butt because I not only added full sides and a back, I added a top. This forced all the air being taken into the system to be pulled in past me.

After adding the soft sides and top, efficiency climbed off the charts. Using an aggressive bit, which really throws the dust, I watch the debris thrown off the cut parallel to the ground, only to do an arcing 90 down into the table. I even router projects in my dust collection table.

It ain't purty, but it works.

Sanding Station-3.jpg

Function is always my motivator too. A member of the old forum once remarked that my solutions usually lacked elegance. I took that as a compliment, even though he didn't mean it to be.

[DaninVan]

I use these in my greenhouse...
https://www.greenhousemegastore.com/pro ... s=e&_v=1.0

[Herb Stoops]

Those would make excellent Dust collection box tops.
Herb

[Stick486]

Those would make excellent Dust collection box tops.
Herb

These work well...
https://www.lowes.com/pd/PLASKOLITE-Com ... ls/3280904

[DaninVan]

The thing about those greenhouse bench tops is their ruggedness. You can stand on them supported only at the edges...I don't recommend doing it but just sayin'. I regularly have 2 or 3 - 5 gal nursery pots filled with wet soil sitting on each one. That's easily 100lbs.