Tablesaw ZCI --- Do they wear out?

[George Bokros]

I have been using the same ZCI in my table saw with the same two full kerf blades for some time and the quality of my cut has degraded, getting some tearout/chipout on crosscuts. The blades were just sharpened so I know it is not the blades.

Do they were out and need to be replaced periodically? I do not make my own I use ones made of UHMW.

Thanks

[Matt Day]

IME, yes. Minor blade deflection for instance can open the ZCI.

Use your UHMW plates as a template for some MDF ones or better yet Corian. Make a bunch so you have extras.

[Martin Wasner]

Yep, they wear out pretty quickly if you're on the picky end and you're cutting melamine.

[Bill McNiel]

My single blade inserts get repurposed for various dado sets.

[Mark W Pugh]

My single blade inserts get repurposed for various dado sets.

EXCELLENT idea!!

[Rich Engelhardt]

Yeah - they wear out. The shop made MDF ones wear out real fast.
I have a Leecraft I use with my Freud GLR that's still doing ok.
I made about a dozen or so MDF ones and just toss those as they wear out.

[Cary Falk]

I have a phenolic one that I put epoxy in the slot and make it new again.

[Dave Cav]

I have a phenolic one that I put epoxy in the slot and make it new again.

That's more or less what I do with my plywood ZCIs; I just epoxy a piece of lath into the kerf.

[Bruce Page]

They do get wallowed out a little with blade deflection but not enough to worry about in most cases. I have been using the same insert for a few years for general cutting. If I need dead nuts zero clearance I slip in a new insert. Eventually the old inserts become dado inserts.

[Edward Oleen]

I get 1/2" plexiglas scraps from glazing shops: I ask politely for some scraps. I can't envision a need for a ZCI thatcan't be satisfied with these scraps. They are scraps to the glazing shop and gold for me.

I usually wind up with an embarrassing quantity of stock: the glazing shop has to pay to have it taken away...

What they call scrap is project material for me, only I don't say so.

Yes zci's wear out: that is why I make several at a clip when I am making them - that way I have a fresh one on the shelf.

[George Bokros]

I have a phenolic one that I put epoxy in the slot and make it new again.

I have UHMW ones and I do not believe expoy will adhere to that material, never tried it though.

[Steve Wilde]

I generally fill them with bondo when they're getting a little sloppy... Cheap and I kind of like the smell!

[Greg Sznajdruk]

They do get wallowed out a little with blade deflection but not enough to worry about in most cases. I have been using the same insert for a few years for general cutting. If I need dead nuts zero clearance I slip in a new insert. Eventually the old inserts become dado inserts.

Bruce could you please identify your ZCI and source of same.

Thanks

Greg

[Bruce Page]

Bruce could you please identify your ZCI and source of same.

Thanks

Greg

Greg, there used to be a couple of outfits that sold them but I can't find them now. They were ~ $100 IIRC.
I designed & made this one for my 1998 RT Unisaw.

[Brian Henderson]

My single blade inserts get repurposed for various dado sets.

Yup. Any time I'm making ZCIs, I make a ton of blanks and as I need them, I cut a new slot, then recut the old one for a dado blade or some other purpose. I have a full set of inserts for every possible dado combination at the moment.

[John TenEyck]

Yes, they wear. I make my ZCI out of 1/2" BB plywood and milled a dovetail slot for a hardwood insert, sorta like the picture posted earlier. When the insert gets worn I just slide it out and slide in a new piece. I used to do the same with the insert in my RAS table, but then tried filling the worn slot with Bondo and liked the result so well that I just do that now for that piece of equipment.

As an aside, I found that after I switched to HiATB blade I have very little chipout when cutting Melamine and veneered plywood, whether or not I use a ZCI.

John

[Alan Bienlein]

All a zci does is make up for not using the proper sharp blade. The material has to be in contact with the zci 100% of the time during the cut for there to be no tear out.

[Ole Anderson]

Greg, there used to be a couple of outfits that sold them but I can't find them now. They were ~ $100 IIRC.
I designed & made this one for my 1998 RT Unisaw.

I bought the same one years ago for my G1023, and added holes for dust collection, not sure it made a difference. I use 1/4" Masonite for the insert.

[Steve Peterson]

All a zci does is make up for not using the proper sharp blade. The material has to be in contact with the zci 100% of the time during the cut for there to be no tear out.

Side to side clearance gets bigger anytime the blade wobbles. This gap is still small on my ZCI that is several years old.

The biggest gap may be the one behind the blade. Raising the blade 2" above the table will result in an 8" long cut in the ZCI. Lowering the blade to 1" will only a 6" long cut. This leaves a 1" by 1/8" gap behind the blade. Cross cutting with a dull blade may result in chipout even with good side to side clearance.

Steve

[Ken Fitzgerald]

I buy my ZCI inserts for my TS at Woodcraft for about $27.00.

[George Bokros]

I buying fro Peachtree for about $22. They are UHMV

[Jim Dwight]

I use hardwood flooring scraps - they're free!

[Steve Peterson]

I use hardwood flooring scraps - they're free!

I do the same. The ones I had leftover were the perfect thickness and have a really tough surface layer. I cut the basic shape on the bandsaw, glued a tongue on the front, and tapped a couple of 1/4-20x1/4" allen wrench leveling screws.

Steve