We are moving our CNC router and connecting it, along with our beam saw, to the same 5000 cfm collector (Dustek M1500) The beam saw requires around 2600 cfm and the CNC requires 1700 cfm, leaving us a little to spare. The beam saw is already on this system and appears to be ducted well, my question goes to the CNC which has a 10" hood where it connects to the system but only requires around 1700 cfm. We have 14" at the blower, which someone has restricted down to 10" going to the beam saw (which seems appropriate) but everything I find suggests something between an 8" or 9" pipe for that volume at 4500 fpm, even though the hood is 10". Will an 8" or 9" pipe going to a reducer at the hood work? I was thinking a 14/10/9 30 degree branch off the blower, a 60 degree elbow, then 10" to the beam saw, and an 9" long radius 90 degree elbow the the CNC. Any thoughts would be greatly appreciated as I'm at the end of my knowledge with this

I believe it is more complex than that. It is about CFM and velocity. It sounds like you are toying with going less than 10". A CNC is hard to collect from. If the manufacturer put a 10" duct on it they did it for a reason.

I agree with Bill regarding the size of the fitting the manufacturer used on their machine. Of course there is more to dust collection needs than the cfm. The speed of the air and size of the duct will ultimately determine the cfm. The general rule for air speed is a minimum speed of 4000 fpm (feet per minute) in a branch. That is the minimum value and you should shoot for between 4500-5000 fpm to maximize the collection of dust and chips on the CNC. The shape of the dust collection hood may require the larger diameter pipe to provide adequate air speed and cfm to collect the dust.

You're dust collector has a 15 hp motor on it. That is adequate in size but the problem I see is the filter area. Looking at similar Dustek models the filter area is only around 136 feet squared. The dust produced in a CNC can quickly coat such a small filter area and create excessive static pressure loss that the collector won't be able to overcome even with the larger motor. You will definitely need to shake your filters often.

I just published an article on our website today outlining the 5 key specifications of a dust collector to understand to choose the proper collector for your application. The article isn't meant to be overly technical, it's written more in layman terms to provide enough information without requiring a person become a dust collection expert. I have provided a link if you want to check it out.

https://nutekmachinery.com/blog/index.php?five-key-specifications-of-an-indoor-dust-collector