dust collection

The motor is rated at 8amps 230V, which is a full 2HP (at 100% efficiency) – just to get that out of the way.

Going to a 4” port will starve the impeller: a 5” will provide approximately 56% more CFM, going to a 6” provides 125% more (more than double) the CFM, relative to a 4”: these stats are for round diameters, not rectangular, so the numbers will change. The importance is that going to a 4”-anything will significantly decrease the CFM. The 875 CFM to 310 CFM (182% increment – 872/310 – is in-line with the numbers above, though this is a broad SWAG).

My guess is that you’re stuck with the port on TS, as I am with my Delta: I just installed the Clearvue CV1800 – all 6” lines, but it is coupled to my Delta 4” x 10” dust port. The CV1800 has a 5hp motor, so I get a bit more through the 4” port: the extra hp struggling against a corresponding increase in Static Pressure through the 4” orifice.

MJCD

-- Lead By Example; Make a Difference

If you are able to change the port on your tablesaw, I’d take it up to at least 6” round. My Jet tablesaw had a plastic cover with a 4” port molded into it. I made a new plywood cover, that used the same fasteners as the stock one, with a 6” hole and stuck my DC pipe into it. Worked great with no flex required. Even if you had to cut some sheet metal to do it, it would help. Some tools it’s just not possible to modify, like my band saw, and you just have to do what you can.

As MJCD said, any 4” will provide a choke point and drop your flow and create a pressure drop. Likewise, minimize the amount of flex hose; the interior of the flex hose is much rougher than any sort of pipe, and will have a much higher pressure drop per foot. Use the shortest length you can get away with. Hard pipe is much better than flex from a pressure drop standpoint. Likewise, avoid sharp angled turns; an abrupt 90deg turn creates a lot more turbulence and pressure drop than a gradual 90deg turn.

-- John