Anyone use a downdraft table for grinding/sanding?

[Gamble]

Moving to a new place and this time the garage isn't all mine and needs to be shared. I would like to keep the grinding dust down to a minimum when grinding parts off the cnc plasma.
I was thinking of a small downdraft table, however I have never used one.
Looking at something like this.
http://www.grizzly.com/products/28-x-39-Downdraft-Table/H2936

The goal is to cut on the cnc with water table and have overhead fume extraction as well and then move the part to here to grind. Hopefully helping keep the floor and cars and everything else clean.

 

[akalian]

That's a lot of money to spend on something that's pretty easy to make.

Here's what I made for my shop. It's portable, and can be used with a 4" hose or a shop vac. The flange is ABS that I got free from Tap Plastics, and the fitting for the shop vac came with the unit. The larger hole accommodates a 4" Dust Collector fitting. The box is just pre-finished plywood and the pegboard can be found at Home Depot in 2' x 4' or 4' x 8' sheets. Doesn't cost a lot either.

The top is pegboard, with double stick tape on all 4 sides and then a shelf liner is stuck to the pegboard. The shelf liner offers a cushion to the parts being sanded, and also keeps them from slipping around. The holes in the shelf liner easily pass the sawdust through the pegboard. I put a handle on it to move it around to the various stations.

The bottom blue thing is an "Offset Blanket". They are very durable with a thick rubber covering over a tough canvas backing. The rubber is very soft and won't slip around or mar any surface.

They are used in offset printing and you can get them from any Print Shop, probably for free. Just go in there and ask to talk to somebody in the Pressroom and tell them you want some "Smashed Blankets". They will know what you mean, but will wonder what planet you are from, to ask for such a thing because the print shop just throws them away.

The local Instant Print won't have the larger ones and they might only be 10" x 15" but the larger Print Shops will have them up to 50-60" wide. You can remove any ink by cleaning the blankets with Lacquer Thinner. The blankets make great non slip bases for just about anything that you don't want to move around or mark anything.

 

[Bdgjr215]

I saw a vac catch fire that was attached to a downdraft table.hot chips got in the vac and smoldered.The boss grabbed it,threw it in the back of a golf cart to take it to the dock and soon as he got some speed up,**** it ignited from the air rushing in it!Crazy and funny at the same time.

 

[Gamble]

No time to make one, rather just buy one. Plus I'm sure it won't start on fire if they use high quality stuff vs a cheap vacuum

 

[dnschmidt]

Not sure it would work. Sawdust is a lot finer and lighter than metal dust from a grinder. The vacuum might not be powerful enough to pull the metal dust into the table. These are common and proven in woodworking. Metalworking I'm not so sure.

 

[FMC1959]

Not sure it would work. Sawdust is a lot finer and lighter than metal dust from a grinder. The vacuum might not be powerful enough to pull the metal dust into the table. These are common and proven in woodworking. Metalworking I'm not so sure.

^ +1. The Grizzly description...last line before the red text. " Intended to collect dust from wood and wood products only. "

Also, probably would not work well with a shop vac, you would need a dust collector and at least 2-3 HP to work well on wood, metal particles could be a struggle.

 

[FMC1959]

I remember years ago being in hardware store specialized for wood workers, a fella asked if they had dust collectors rated for metal particles. This place had Jet, General & some lesser brands, none were rated for metal. They suggested he go places that specialize in commercial metal fab equipment. If there is a down draft table and dust collector rated for metal particles, one of these places would have or know of them.

Not sure if this could work, but what about a "spray booth" for grinding. You said your goal was to keep the dust level going to your neighbor at a minimum. If your cnc machine is liquid cooled, that should not be an issue for dust. For the grinding, if you go to HD in the materials section near the drywall, they have the plastic and adjustable poles to make a booth to whatever size you need, with the zipper front to go in and out. If there is any issues with the sparks hitting the plastic walls, make a back splash for your work table. Simple plywood and if necessary, cover the plywood with a metal or other nonflammable material. A plan B if you can't find a down draft table, good luck.

 

[Gamble]

They have this one but it's more than what i will need
http://www.grizzly.com/products/22-x-62-Metalworking-Downdraft-Table/G0798?utm_campaign=zPage

 

[akalian]

A friend of mine has an Oneida Cyclone Dust collector.

And believe me when I tell you that it will **** the chrome off a trailer hitch.

http://www.oneida-air.com/pdf/wood_mag_dec_2003_twister_test.pdf

Grizzly has one as well, but I don't know how it stacks up against the Oneida.

http://www.grizzly.com/products/2-HP-Cyclone-Dust-Collector/G0440

.

 

[helterskelter]

We have large industrial downdraft tables with water flowing at work designed specifically for metal use. They were significantly more expensive than the little grizzly. We grind a lot of titanium and the metal dust can be flammable if not handled properly. They do work extremely well for keeping the dust down.

 

[Gamble]

Anyone else?

 

[McLean]

I like to keep a clean shop, but some of these jobs are just duuurty. My only solution has been trying to minimize the use of angle grinders wherever possible.

From time to time I see Donaldson Torit and similar industrial metal dust collectors on craigslist at very reasonable prices. you might even be able to get away with one collection system for both the plasma table and downdraft table.

Seems like a pain to use, but I have seem some angle grinder shrouds w/ vac attachment. I think they are intended for a different purpose, but could be worth a looksies.

Just curious, why are you grinding parts after CNC plasma? just deburring?

 

[BFBOB]

No, but I witnessed the concept at the GM plant many years ago. Painting cars with NO protective gear! Mighty impressive. As I recall, nearly the whole floor was a grating with suction (MASSIVE suction) applied, and inlet louvers on the ceiling. The same principle should apply to any similar process. More on point, I have the whole cabinet of my table saw blocked as much as possible and still alllow the arbor to tilt, and a 3hp dust collector connected to the bottom. The difference in how much debris is ejected topside out the blade slot with vacuum on vs off is dramatic.

 

[Gamble]

I like to keep a clean shop, but some of these jobs are just duuurty. My only solution has been trying to minimize the use of angle grinders wherever possible.

From time to time I see Donaldson Torit and similar industrial metal dust collectors on craigslist at very reasonable prices. you might even be able to get away with one collection system for both the plasma table and downdraft table.

Seems like a pain to use, but I have seem some angle grinder shrouds w/ vac attachment. I think they are intended for a different purpose, but could be worth a looksies.

Just curious, why are you grinding parts after CNC plasma? just deburring?

I grind the back sides to remove all the dross.
On steel I grind the front to shine it up or remove mill scale.
They don't come out perfect, they always need some type of post clean up. Some stuff I'll take a file to the insides, or on aluminum I take a file to the edges.
I do like to sell my stuff "right off the table" but not everyone wants that.

 

[redmondjp]

Related to flammability concerns: at one manufacturing plant that I worked at, we had welding fume vacuums that had huge pleated paper air filters (similar to those used on heavy trucks and construction equipment) inside. At least one of those caught on fire every 4-6 months (fire was contained inside the unit every time, but the smoke exited the roof from the stack, resulting in welding shop evacuation and fire trucks showing up).

And it was the particulate accumulated on the filters, from welding, that was catching on fire. Stuff that you would never think was flammable.

 

[bluebolt]

Crazy quick idea, venturii vacuum blowing into a 55 gallon drum partially filled with water to cool down any hot sparks or dust?

 

[Gamble]

Crazy quick idea, venturii vacuum blowing into a 55 gallon drum partially filled with water to cool down any hot sparks or dust?

I tried to do a little fume extractor on my cnc plasma table. I built a source to pull vacuum and hooked it up to a small fan and took the outlet and put it into my water table. The idea was good but it just blew too hard and made a lot of bubbles splashing all over and made a big mess

 

[Gamble]

I still may try this thing. I don't do a TON of grinding but I do some. And if I built the walls up a little it would catch and fall, but what I do a lot of is sanding metal with my little DA sander for clean up edges and give a nice finish.
So IDK?

 

[Gamble]

Think this would be ok to catch overspray from spray paint and powder coating?