Zero Clearance inserts, why?

[Karl Brogger]

A very high percentage of posters on here are infatuated with them. When I used to use melamine I'd use them as it would act as a backer of sorts and prevent some chipping. Now the only time I use one is when I'm making drawers I cut a 1/4" off of each edge to remove the tearout from the router bit, and its nice having the drop just sling off of the table rather than dive into the saw cabinet. Other then those two things, whats the point?

Or am I missing something?.....

[Tony Bilello]

I find that I get a cleaner cut with less tear-out with ZCI's. It is kinda like the theory of a backing board when making box joints with a dado blade.
I also make thin cuts at times when making veneer. Without the ZCI, the veneer piece would get sucked down the blade into the black hole.
That'a all the reason I need.

[Brendan Plavis]

I hear that it also assists in preventing kickback.... But dont take my word for it... used a tablesaw once, never use one again(unless I get a really nice sliding one...)

[Paul Atkins]

They keep the little cutoffs and splinters from catching between the blade and insert too. I don't know why you wouldn't want one. The factory inserts are generic for multi-use and don't do the best job anyway. I used to make ones from bb and put adjusting screws in them, but once they were adjusted I never needed to do it again, so I just made them fit the first time. I must have had 5 or 6 for different setups from thin kerf to dados. Now I have another saw and only 3 inserts.

[Derek Noel]

I use them when i am working with small or narrow parts because they need the support and small cut off pieces don't always fall nicely. I have had small scraps get wedged between the side of the blade and the opening of the insert and either burn until i shut off the saw or come flying out.

[Zach England]

1) prevents tear-out
2) prevents small cutoffs from falling into the saw
3) improves dust collection by causing most dust to fall into the saw
4) in saws like mine that do not have riving knives it allows for easier splitter mounting

[glenn bradley]

Good answers all. Zach hits all my reasons. Even folks that use them after they are not quite so "zero" anymore get the protection from small cutoffs becoming projectiles. I make them several at a time and toss them on the scrap pile once they get tired.

[Robert Reece]

I would dispute Zach's #3 claim on the dust collection. I have an over blade guard with dust collection and when I can't use it, I switch to a non-ZCI if appropriate for the cut (no small cut offs). I find the non-ZCI collects more dust than the ZCI when I am not using my overblade collector.

[Chip Lindley]

+1 on FRESH ZCI's. After some use, at different blade heights, they do become tired. I consider them expendable when made of scrap melamine. No way will I buy them for $12 each!

Two patterns need be constructed to make an armload of 'em! Make a template of the outside profile which will fit exactly into your saw throat opening. Made a pattern to route out the clearance where the ZCI rests in your opening. These are screwed to the underside of each blank and run across the router table. Great little project on a slow day.

[Steve Griffin]

I like to buy them, as maybe I'm not so fussy about them getting a little sloppy with use.

As I mentioned recently in another thread, besides the convenience of factory made inserts, I really like the safety orange color. I'm sure it sounds silly to some, but I'm convinced there is a tiny safety advantage to having your eye/mind key off the bright color when clearing off falloff etc.

[Zach England]

I would dispute Zach's #3 claim on the dust collection. I have an over blade guard with dust collection and when I can't use it, I switch to a non-ZCI if appropriate for the cut (no small cut offs). I find the non-ZCI collects more dust than the ZCI when I am not using my overblade collector.

This was a bit of conjecture on my part. It may not be true that more dust falls into the saw. The reason I said this is that when I use a regular insert I see and feel a lot more dust coming up at my face than when i use a ZCI. The caveat is that the dust collection in my table saw is pretty poor. Of all the things I dislike about my Jet this is the highest on the list. The dust collection only serves to suck dust out of the bottom of the cabinet. Getting it into the cabinet has to be entirely a result of gravity. I imagine with useful suction at the top of the saw it would be a different story.

It probably depends on the type of cut, but since I rarely use a regular insert I have never really been compelled to experiment.

[John Thompson]

A very high percentage of posters on here are infatuated with them. When I used to use melamine I'd use them as it would act as a backer of sorts and prevent some chipping. Now the only time I use one is when I'm making drawers I cut a 1/4" off of each edge to remove the tearout from the router bit, and its nice having the drop just sling off of the table rather than dive into the saw cabinet. Other then those two things, whats the point?

Or am I missing something?.....

Those two things are the point!

[Louie Ballis]

I might be wrong, but I think that the dust collection is superior withOUT the zero clearence insert (grizzly 3hp 1023 tablesaw).

[Prashun Patel]

I love my zci's.

I heard if you elongate the slot of a ZCI, you can improve dust collection.

[Louie Ballis]

I

I heard if you elongate the slot of a ZCI, you can improve dust collection.

I never thought of that