I have a massive Grizzly 2HP 220v 2 Stage dust collector. The link is below.
This dust collector has a 7" air intake port that splits into 3 4" ports. One port I have a hose coming out, one port I always keep close and the third port I have a blast gate on that is half open. The blast gate does not connect anything, it just helps me control the air flow. This is the dust collector I will be using for this CNC and the rest of my shop. I don’t have ducting, yet. I just have one hose and the Rockler Dust Right quick connect system that I have been using for a couple of years.
I have some concerns about connecting this massive system to such a small 2.5 in port. I am not sure if this is an unfounded concern, but I have heard that choking a system down dramatically reduces the suction.
Does anyone have a large dust collector for their CNC? Are there any mods that allow for a direct connection of a 4" port? I think this would be very valuable to the community.
Thanks in advance.
Here is a model of how my garage shop will be after I build the 9x5 workbench.
I have the Harbor Freight dust collector, which is sold as being 2 HP, and I use it for my main LowRider. My understanding is there is benefit in keeping the diameter up (i.e. 4") for as long as possible, only changing to a smaller diameter as close as possible to the machine. Also, that the smaller diameter should not be any smaller than necessary, with 2.5" being the low limit. Mine has always been 4" transitioning down to 2.5" — this has worked “decently” well for me.
CENTRAL MACHINERY 35 Gallon, 2 HP High-Flow High-Capacity Dust Collector
Going against the run of play here perhaps, because this is internet and advice is no good unless it’s conflicting!
I have a 2.5HP dust collector - ducted with 6"PVC and drop down to 4" at all the gadgets and a secondary 90mm dropper to bandsaw and top of tablesaw.
Dust collection is good for collecting dust, if it’s set up well, particularly the nasty fine bits that do you harm.
This is why the machine is not visible - it’s in it’s own little lean-to cupboard OUTSIDE - where all the fine unfiltered bits don’t matter quite so much.
If you can manage a proper overhead setup and your system is working well through very short duct runs, a 4" system will work.
There are too many vagaries for me in that - so things like my LR, my sanders and hand tools are directly fed into the vac setup (the LR with a 2" system), and fine dust is mostly eliminated by 6" belmouths above the machine.
Not visible in the pic are two exhaust fans (8" from memory) which enable enough airchanges to more than meet any OH&S standard, and take care of all (most of) the microfine residual stuff. Yes it sounds excessive, but with a father and two brothers in law who have died from dust related lung illnesses and a wife who has her sewing setup separated by a two metre wide sliding door - it works for me!
Have a poke around in my dust collection fittings models - I do have a full parametric version of the bellmouths, but haven’t uploaded it - I can easily customise the size if you decide you want one.
