Dust collector selection and sizing

I currently have no dust collection system. I'm looking into something capable of servicing a grinding station as well as a CNC mill and eventually a CNC lathe for machining graphite and composites. I've searched here and found information suggesting a HEPA equipped Torit or similar, but no information regarding sizing. Would a 1/2 or 3/4 HP Torit like the below be sufficient or is a larger unit required to ensure larger particles are captured?

Donaldson Torit Cabinet Dust Collector Model: 60 CAB | eBay

Graphite milling is a messy business. Make darn sure whatever you choose will filter that stuff AND not need to be changed out weekly.

Your biggest challenge is the size and shape of the capture opening or dust hood. That little Torit unit can do it if equipped properly. Emptying it without making a mess is another challenge.

Thanks for the replies. I've read that graphite is nasty to work with, which is why I made this thread. I want to try to capture as much of it as possible. I'll be milling on a grease lubricated machine so I'm concerned with contamination. I'm not sure if its realistic to expect any vacuum system to be able to keep all the graphite out of the linear guides and off the ball screws (and out of the shop).

It will get every where even with a real good dust collection system. One of the biggest problems is when it mixes with grease it turns in to a paste that can lock up bearings. So be diligent on cleaning. Oh and don't be afraid of taking big cuts cause if you don't it will wear your inserts out quicker.

DFE2-4 Dust Collector | Donaldson Torit By the way this is the dust system we used for just one cnc mill. We had much larger ones for the other machines but we machines contaminated graphite on one mill and used this collector.

I can't answer what will be best. I do have one of those little 60 CAB collectors. I got it at HGR. It's a really nice little device. It's really a one machine box. I have mine hooked to my blast cabinet. It has a shaker in it for knocking the crap off the bags. And there's a little pan underneath for the dust to fall into. The bad thing is that the bags for that collector are like $300 or so. You may need a higher efficiency filter after the box for your application. Maybe not a HEPA but more efficient than a cotton bag filter which is what these have.

In my past job we did a lot of fine dust collection. Some of the air was returned to the plant but most not. Generally when we reused the air we HEPA filtered it but this was a pharmaceutical application and we had to HEPA filter for regulatory purposes. It was the only way we could be sure to prevent cross contamination. In other industries I think a little trial and error could be used. Start with a dust collector and see what gets past it. If you still have issues add another filter stage. HEPA's are very expensive so I would only go that far if you really need it.

If you're not far from HGR they generally have various dust collectors and some can be had cheap. Whet you wind up with also will be dictated by your power availability. You can get into a 10+ hp fan pretty quickly.