[jeffmorris]

My "new" CNC router came with a dust collection hood. I tried a small Shop Vac but the suction wasn't strong enough. Are there best Shop Vacs that can fit through a 12" X 16" door in the side of the CNC router cabinet? I want to get a small dust collector like the one in Portable Dust Collector, 3/4 HP, 115/230V - Dust Collectors - Finishing Supplies - 3AA30 : Grainger Industrial Supply
Which Shop Vac or small dust collector is best?

[bobsch]

Another source for dust control is Harbor Freight. Here's a couple of small units for much less than Granger.

Portable Dust Collector - 13 Gallon

1 HP Mini Dust Collector

[tinkeringtechie]

By "suction" are you referring to pressure, or the air flow (volume)? Typically Shop Vacs have plenty of pressure, but less volume. The other problem is that they'll get clogged with dust pretty quickly, so a dust separator would almost be required. Exactly how much space do you have, and what's your budget? The dust collector you listed looks fine, but here are a few other alternatives:

G0710 1 HP Wall Hanging Dust Collector
Dust Right® Wall Mount Dust Collector - Rockler Woodworking Tools

Keep in mind that dust collectors don't usually get the really small particles very well (<10 microns) so you'll still need a respirator or air filter of some sort to get rid of those.

[jeffmorris]

The dust collection hood has a 1.25" hose and the Shop Vac has a 2.5" hose. I removed the metal plate at the back of CNC router's cabinet and installed one with 2.5" hose connector. I removed one of the vent covers and routed the 2.5" hose back inside the cabinet. I made a "Y" adapter to connect two hoses to one Shop Vac. Even with a clean filter, the Shop Vac won't pick up larger wood particles. I checked out the small dust collectors made by Harbor Freight but I'm not sure if they are as good as more expensive dust collectors.

[OCNC]

It sounds like you're trying to collect the dust from the cabinet. You need to have the dust collection located right at the tool where the cutting is taking place. The vacuum nozzle needs to be within a couple of inches of the cutting event and moving along with it. Further away than that and you won't get much more than the fine airborne dust.

Chris

[ger21]

If you're thinking of connecting a 4" dust collector to a 1-1/4" connection. Don't. It won't work. The problem is that a 1-1/4" hose just won't allow enough airflow through it.
Fwiw, a 20HP dust collector won't pick up all the larger particles.

[Dylwad]

Best bang for the buck is the harbor freight collector with a 5 micron rockler bag, no complaints with mine, and it has seen daily use for 2 years with no issues.

Use a 4" hose and dust boot around the bit.

[jeffmorris]

I'll put a gate on the 2.5" hose coming out the back of the cabinet. I'll close the gate when cutting and open the gate when cleaning out the cabinet.

[vtx1029]

Don't waste your $ on the 1hp harbor freight dust collector. Its a POS. Had one and the only thing it did good was make noise. I have the 2hp harbor freight dust collector now and the only problem I have is it fills up too fast

[brtech]

The 2HP HF DC is a gem. Lots of woodworkers swear by it. Best bang for the buck in DC. You can find a coupon for it in Woodworking magazines for $139 or $149.

The stock filter on it isn't good enough. If you are going to be milling wood, you should have a canister filter that filters down to .5 microns. That is true no matter what kind of DC you use. The recommended unit is a Wynn Environmental 35A, which raises the cost of the HF considerably, but to get equivalent filtering on any other unit is going to be the same.

When you plumb a DC, you can use flex tubing or rigid pipe or a combination. No more than 10' of flex if that's all you use, and if you have a combo, best to keep the flex to only a few feet (like from your ceiling to your dust hood). You can use 4" Sewer and Drain PVC pipe for rigid plumbing. Don't use 90 degree elbows unless they are wide sweep. Instead, use two 45s with a short straight section between them. Use Wyes instead of Ts if you need a branch.

A real nice addition to the HF DC is a Thien baffle. Google it. Easy to make, and you can put it in the "ring" of the DC. Works like a cyclone to better separate chips from fines.

[Vestus]

Here's a great example of what you can do with the HF DC. Adding a primary with a Thien baffle and a pleated filter works wonders.

Harbor Freight Dust Collector Mod - by Cory @ LumberJocks.com ~ woodworking community

[msimpson99]

I am a dust fanatic. I have a central Cyclone system in my shop and several high end vacuums as well. There are two ways to collect dust from your CNC.
Brute force:
Use a large enough system to overcome all the air turbulent your router creates. In this case you need to have a good seal around your stock (dust shroud) and use a lot of suction. Like connecting you 6” central shop vacuum to your dust hood. This is ok for large machines but does not work very well on small ones.

Work Smart:
I found out a while back that if you can take the vented air from your router and vent it in such a way that it does not enter the dust shroud/stock area, you don’t need a lot of suction to remove most of the dust. You can’t just divert the vented air. The vented air must be isolated from the inside of the shroud. It took me quite a few iterations but this is my final design.

[ame=http://www.youtube.com/watch?v=xta-vQGYts4]Kronos Robotics Air Exchanger - YouTube[/ame]

I call it the air exchanger. Unfortunately the current design only works on CNC machines with a K2CNC router mount.
I use them on all three of my CNC machines. I use Fein Turbo III on one and Rigid $99 shop vacs on the other two.

Here is the link to my AirExchanger product page.
AirExchanger

We are also working on a clamp on version that will attach direcly to most routers.

[jeffmorris]

My shop teacher got me the small Delta AP300 dust collector that belonged to his brother who's a shop teacher but I couldn't use it because I need some parts to connect the hoses to the dust collector.

[jeffmorris]

I got the parts to connect the hoses to the dust collector but the suction isn't strong enough. There may be leaks so how can I check for leaks?

[ger21]

Are you running a 4" hose right to the tool? If not, you'll lose most of the suction with a dust collector like that.

As for leaks, just wrap some duct tape around all the connection joints.

[jeffmorris]

I ran 2-1/2" and 1-1/4" hoses to the dust collector using a "Y" adapter made from pipes and fittings. The pipes have inside diameter of only 2". I used two 3" 90-degree elbows to connect the dust bag to the dust collector. I will try to get the "cheapskate" shop teacher to get dust collector parts from online woodworking supply store. Is there any way of increasing suction power?

[Dylwad]

Dust collectors move lots of air at low pressure and need big hoses, vacuums move less air at higher pressures.

Anything smaller than 4 inch wont work well, and any sharp bends or tees in the line hurt performance.

Think of it like blocking off part of a fan, the air coming out around the blocked off section doesnt raise in pressure like it does when blocking the end of a garden hose off with your finger.

Get a bigger hose, try to have a smooth run with no sharp bends.

Pictures of your setup would be nice to see

[jeffmorris]

Would 5" HVAC metal duct fittings work (90-degree elbows) work between the output port and the bag? I tried to have a smooth run of the hose coming from the dust collection hood but I'm afraid of cutting the hose because a ground wire is attached to the end of the hose. I found out that my dust collector with 3/4 HP motor generates 680 CFM. A Delta 50-850 dust collector with 1-1/2 HP motor generates 1200 CFM. Can I replace the motor and impeller in my DC with the the motor and impeller made for Delta 50-850 DC?

[ger21]

No, you can't just swap motors and impellors. The Delta is probably much larger and likely won't fit in the housing.
Note that manufacturers CFM ratings are usually greatly exaggerated compared to real world conditions.

I have a very old 1HP Craftsman that I would think is better than you're 3/4HP model, and when the bag is half filled, airflow is restricted enough to greatly reduce the suction.

Going to a larger duct can be just as bad as going with too small a duct.

The Delta is probably comparable to the 2HP Harbor Freight, mentioned above. IF you already have the Delta, then why not use it?

[jeffmorris]

I would use the Delta 1-1/2 HP dust collector but it's in the other end of the wood shop connected to some sanding machines, covered with dust, and too noisy. I managed to put the Delta AP300 dust collector inside the CNC router's cabinet using two PVC 90-degree elbows between the output port and the dust bag but the inside diameter is about 4". The output port is 5" and the input port is 4". The hose from the dust collection hood which is made of aluminium is 1-1/4" and there's no room for 2-1/2" hose.