Adding Ducting To New CNC

10/22/2014


From original questioner:

I just bought a new router and set up a ducting system to all of my equipment for dust removal. Originally, my CNC salesman told me that I needed an 8" duct over to the machine. So I set up a nice pipe with a ball joint on the end. Well, it turns out that the machine has a 10" port- not 8". My salesman told me that I should just put a 10" to 8" reducer on the end of my ball joint (backward of course). However, the guys who did my ducting are telling me that if the machine has a 10" port that I am missing out on quite a bit of CFM if I don't switch to 10". Any thoughts on the situation?

From contributor ja


Basically it is the water thu a straw concept,

yet at 8 Inches (and if you have already put an 8 inch system in place) I would hook it up and see if it will suffice, that is still a lot of pull power

From contributor ca


Get yourself @ least a 10hp collector with a 12" main, if not a 15hp. You really need the volume to get the velocity with big of an opening. (Find another machinery salesman. he is going to convince you to do something very regrettable, eventually).

Mine convinced me to get a 15" hp and my cnc router has a 12" main. No regrets

From contributor Le


Keep the duct collector under 5000 cfm if it is indoors to avoid problems with Insurance and OSHA

From contributor La


We've got two routers one runs off of a Torit 5hp with an 8" duct and works well. The other runs off of our 20hp outdoor collector (18" main) into a 12" ball. It is a pod & rail machine so pickup is more difficult. It works fairly well considering how open the work is.

I'd try the 8" you've got before changing anything. Salesmen should never be relied on!

From contributor ri


Don't you get the same CFM no matter what the size of duct? It's velocity that changes. To keep the velocity in a 10" pipe, you need another 700 to 800 CFM more than in an 8" pipe. Did your pipe guys give you a velocity chart? I'd put the reducer right at the machine so the velocity stays up in the piping for a start. I guess you get the idea that I think velocity is more important at a CNC. Thickness planer, way different story.

From contributor Jo


It's ultimately going to just come down to trying it out and seeing how it works. Looks like that won't be for a while though- brand new machine and the spindle went out. Very disappointing.