Learning about CNC routers: Dust Collection

[kinghong1970]

I'm seeing many folks use Dust Shoe + DC on their machines.

i see some folks use shop vac hose, 2 1/2" hose, up to 4" hose and of course, the many creative models of dust shoe...

my experience with dust collectors, well, 1hp delta model i've hooked up to a couple of drops and with blast gate is a bit weak. i'm thinking that this DC is intended for a single machine connection...

a 6 hp shopvac with a separator stage seems ok, but again, not enough...

i've been meaning to upgrade my shop DC system... and was curious...

1)how much dust collection is sufficient for a cncrouter system?
2)how much hp is your dust vac? (many pics seem 1hp HF/Grizzly models)
3)if you have DC hooked up to a shop vac, is it sufficient?
4)from your experience, what would you recommend as a minimum setup? (DC hp, hose dia, etc...)

again, thank you very much for your replies.

[ger21]

I currently use an old 1HP craftsman, with a 4" hose. It's not bad, but I bit more suction wouldn't hurt. It's hard to beat the Harbor Freight 2HP unit when it's on sale for $150 or less.
I wouldn't want to use a Shopvac, due to the noise factor.

The shoe design is critical for good dust collection. You'll see all different materials used for a skirt, but imo, a good brush is the best method. For best results, the brush needs to form a "seal" to the part or table. Any gaps between the brush and table will allow chips to get out, regardless of how much suction you have. Chips are thrown at very high velocities, and the brush is needed to contain them within the range of the vacuums suction.

Keep in mind that some operations are bound to let dust and chips escape, no matter what you do. But a good shoe design will allow you to cut sheet materials with zero airborne dust, and very few particles left on the table.

[ssutton]

I am using the HF 2 hp model. I got it on sale for $139.00 with an online coupon. It even has a steel impeller, some of the others have a plastic impeller. I have no dust issues whatsoever, however, some times larger chunks will get ejected from the material and escape.

HIGHLY RECOMMEND THE HF 2 HP UNIT.

Scott

[Grunblau]

My setup currently is a 5HP small box vacuum (4.5 Gallon) Since holding capacity doesn't matter with a Dust Deputy inline...

Box Vac

Dust Deputy

I used to have to hit Feed Hold to clean the filter mid cut especially while milling foam. With the dust deputy, I haven't even looked in there for over a year, lol.

One thing to overcome is that the suction is so hard that it collapses the Home Depot Bucket. I had to put a structural rib inside to prevent this.

Brian

[vid1900]

Bill's Cyclone Dust Collection Research - Home Page

Best read on dust collection anywhere.

[kinghong1970]

Bill's Cyclone Dust Collection Research - Home Page

Best read on dust collection anywhere.

yep, did read up on it for a while...
but before learning on the cfm requirements and hp requirements, i actually tried a cheap cyclone



while it works to separate larger chips, i can still see dust in the DC bag.

and it's not quite the chips that worry me, it's the <0.5 micron dust that stays airborne... hence i have a filter running most of the time.

not quite ready to invest in a 5 hp cyclone... and since i can vent the DC outdoor to the woods, i was thinking of just upgrading to a 3 hp grizzly cyclone model...

just wondering how the 1hp or 2 hp with 4" duct works for router chips.

Al

[harryn]

I play a little with wood gasifiers, and the clean up method becoming popular for that application are venturi scrubbers. (as a final stage, after the conventional collectors)

See figure 6.

Venturi scrubber - Wikipedia, the free encyclopedia

[brtech]

The HF DC can be used with 25-35' of pipe, a few wyes and blast gates. You might be better off with 5" main, but 5" pipe is expensive and/or hard to find, so most folks use 4".
Just don't use a lot of flex, and either use wide sweep elbows, or two 45s and a short straight section between them. You would only want to use it on one machine at a time.

What you need to do is have a <.5 micron filter. For the HF and most of the similar models, the Wynn Engineering 35A cartridge filter is a big boost in filtration and airflow. I highly recommend it. An air cleaner is not anywhere near as good as putting better flitration in the DC. Once the dust is in the air, it gets in your lungs. The air filter gets it out of the air eventually, but you are breathing it until it does.

Adding a Thien baffle is a good investment, but a cyclone is probably better. I believe most of what Penz says, but can't afford it.

So, I think it gets down to whether you want to have another tool running while you are running your CNC. If so, the HF and similar DCs are probably not good enough. If not, Penz would say they can't get the CFM you need, but with the Wynn Filter, they do pretty well.

[jckstrthmghty]

I run a 6hp shop vac with a hepa filter attached to a cyclone. Works great but as ger mentioned it's a bit loud.

[kinghong1970]

eventually, i want to upgrade to a better cyclone for my basement shop...


and also reduce the pvc pipe runs that i have going on at the moment.
probably put router table and drill press on wheeled base to roll into position.

i have 2 acres so neighbors are at a distance away... i'm actually considering venting outdoors to a bunch of shrubs.

i guess for the time being, i'll use my shopvac...

[Phife]

I run a 6hp shop vac with a hepa filter attached to a cyclone. Works great but as ger mentioned it's a bit loud.

just keep in mind that that 6hp rating is not the actual rating of the motor, a 6hp shop vac does not actually have 6hp, more like less than 1hp probably.

[ger21]

I've read that a lot of people get away with using the 5" snap together duct from Lowes or Home Depot, which is dirt cheap. They say a 2HP Harbor freight isn't strong enough to collapse it. I'm going to try it when I build either a Thien or a cyclone.