Holes in Sleds and TS ZCI Plate for DC

[Patty Hann]

I was looking at a different thread Overhead guard for TS (https://sawmillcreek.org/showthread.php?302584-Overhead-Guard-for-Table-saw&p=3246308#post3246308) and went to the the Shark Guard website for more info.
And I saw this (see pic).

Shark Guard aside, I wondered about the effectiveness of drilling holes in the ZCI plate and the sled (any sled).
Is this a good idea? Would it really help DC (especially with a jobsite saw such as I have-- 7480)
Any drawbacks to it?
I am totally ignorant of fluid mechanics, so I need wiser heads to weigh in on this.

497789

[Monte Milanuk]

I tried drilling some holes in the sled, and in the ZCI. The holes in the ZCI helped a *little*, when using the saw without the sled - but not enough to overcome/capture the dust spewed out by an edge cut. The holes in the sled seemed fairly ineffectual - I even went so far as to remove the throat plate underneath entirely (serves no purpose with the sled on top of it) and still didn't get any great amount of suction / air flow down through the holes. This was on a 10" hybrid saw (Ridgid 4512) with a 1.5 HP DC (Delta 50-760) plumbed to the saw with about 10 ft of flex hose. Other DC configurations - like a hard-piped 5 hp Clearvue cyclone - may yield different results.

[glenn bradley]

There has to be make up air in any captive space that is connected to a vac or a DC. I generally used the gap between the table and the cabinet of the tablesaw for this air. The blade removers spoil, takes it immediately below the table where it should fall into the air stream. I do not think you need additional holes at the top. There is generally material laying over that area anyway(?).

[Patty Hann]

There has to be make up air in any captive space that is connected to a vac or a DC. I generally used the gap between the table and the cabinet of the tablesaw for this air. The blade removers spoil, takes it immediately below the table where it should fall into the air stream. I do not think you need additional holes at the top. There is generally material laying over that area anyway(?).

Yes... the holes in the ZCI plate (using the TS w/o a sled) could be covered a lot of the time with stock (depending on width and width of cut)
But I wondered about holes in both the ZCI plate AND the sled together....but I guess Monte answered that already.