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I've decided I'm going to install the CNC indoors, in my top floor room becase the shop is simply too cold/humid at times - I have an indoor workspace which is where most building takes place, and the outdoor shop for machining, big tool use, that sort of thing. What this does mean, however, is that I'll be getting two additional bits of equipment:

1) A vacuum pump, probably oilless, although I'm a bit stumped on the CFM rating required. The price difference between a 4.5 cfm and a cfm (23 L/min and 128 L/min) is negligible, so I figure too much is better than too little. Both are fairly quiet, 35db rating.

2) Some form of dust colleciton, as the full-sized collector is down in the shop. Is a (powerful) shop vac enough? What kind of airflow would you guys recommend, and what type of dust collection setup? Cutter hood, something else?

Vac pump - depends on what you expect from it. If you're going to use something like a puck the pump doesn't need to be very large. I use my 1.1cfm pump to hold solid wood in dedicated clamping jigs without any problems. A bleeder table is on my wish list, but from what I've read they really require multi horsepower pumps. As far as db's, you probably won't hear it over the router or dustcollector.

Dustcollector - depends on what you're going to cut and how well your collection system works. I think a dust shoe (mine is simply an oval piece of mdf with a hole for the router and another for the hose with a bristle skirt running along the side) is probably the most common solution. With a good dustshoe setup you can probably get by with just a strong shopvac. I think the key is having multiple setups (different brush lengths) for different cutting depths. My current setup has 3" long brushes which I think are too long for most of my work. I've got a Delta 1.5hp dc connected with 4" hose. I get plenty of air flow, but it leaves a lot of dust on the table. I think shorter brushes would fix that problem. If you're planning on machining a lot of MDF I'd get a dedicated DC especially since it's going to be in your house. MDF dust gets EVERYWHERE. I've been running my machine since July and I've already collected 4 big bags of it. That's probably at least a dozen bags if I were using my Fein shop vac, so add in that hassle factor for a shop vac.


Bob

Thanks, food for thought. I suspect I'll mostly be using small area vacuum, not a universal full vacuum table, so the smaller pump should do the trick.

In terms of dust collection I'm strongly leaning towards a medium-powerful shopvac type system with a mini cyclone (dust deputy-like, probably make my own out of plexiglass unless shipping's not too evil), and build a (removable) enclosure for the machine to contain any errant dust particles. It's going to be set up under a desk ledge, so that solves the 'top end' problem, at least.

My biggest 'issue' is making heads or tails of various manufacturer specs; most list some form of air flow, but suction (which strikes me as almost as important) is hardly mentioned anywhere. I'll probably go with a device from Axminster (UK seller) unless I find an elegant solution locally.

Hey Mattia

You could use a vacuumpomp from an old milking machine (for milking cows that is)

You don't need much vacuum CFM if you make good fixtures. I use a 4CFM pump and it's more than enough. You need enough CFM to make up for the leakage in your system (and they all have some: wood is porous) and at that point the more vac the better (16" Hg, which is what big industrial units for sheet get, isn't nearly as good as 25-27" Hg from a small low-volume pump)

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services