Dust Collector Hose

[woodchucker]

Maybe grinding dust will work out OK, but I have been disappointed with the performance of 4" ducts on metal chips. I have a 2.5" shop vac and hose that works well, even with long curly chips.

4" duct with how many cfm dust collector?
I'm with Eddyde on rigid pipe as much as possible. It doesn't slow the air down as much as hose, so it helps to keep the draw up.
Slow sweeps are important.

A vac and dust collector operate differently. A vac will move the grid and swarf if it catches it. A DC's job is to GET IT. The idea is to catch more air and catch the stray dust that is a little further away from the pickup. I like PVC pipe for a DC. The problem I have with metal piping is that if you go cheap and go with HVAC pipe, the seam slows the flow down, and it leaks. You need to go with the next level , which is DC pipe to do it right.

 

[Winegrower]

4" duct with how many cfm dust collector?

I don't know offhand without going out in the rain to the shop. It's a 1.5HP motor or so.

My dust collector works fine on wood chips and dust from the table saw, bandsaw, jointer and planer. I perhaps thoughtlessly tried it on the mill and lathe...not good. The shop vac is what I use on the metal equipment, and also the router table, which generates so many chips so fast that the high velocity air does a better job keeping up than the higher volume lower velocity dust collector.

But the dust collector bag would not be good for metal anyway. I'm happy it didn't work.