Making a ZCI for tablesaw

It is easy and yes, you're thinking too much. Been there and was amazed at how easy it was, after I finally just did it instead of planning it.

I used quality 3/4 Finnish birch plywood, then used a planer to get it down to pefect thickness.

thickness.http://picasaweb.google.com/mikeadiddle/ZeroClearanceInsert#>> Check out this video...

I've seen the video before and now caught something that the editor said, he said the ply was "close" to the thickness of his standard insert. Thinner is better, is what he said.

Thanks,

MJ

Just get some 3/8 material: ply, Baltic birch, Plexiglas, phenolic, lexan, melamine covered termite puke, medium density termite puke, aluminium, whatever & go for it. It's not as it needs to bear a lot of weight.

Luigi

thickness.http://picasaweb.google.com/mikeadiddle/ZeroClearanceInsert#>>>> Check out this video...

I have no idea. I'm guessing it's near 1/2. 1/4" is nothing for a planer. Heck, 80 grit paper on a flat board would do the trick in a few minutes with some elbow grease. Just leave the top side untouched to make sure it stays flat.

The bottom doesn't natter much, especially if you're using leveling screws.

If yours is 3/8", you could start with 1/2" and plane/sand down in no time.

One reason to use thicker material is flatness. 3/8 material, even Baltic is less likely to be as flat as 1/2 or thicker. A twisted insert will be nothing but a pain in the ass. I suppose that is one reason why people use thicker material. Also weight is a consideration. You don't want it to be so light it is flighty or easily upset, you can think of the scenario where it jumps out of the slot and catches the back of the blade and does a quick fly-by of your ear.

Finally, please replace your planer blades after planing ply. Really not a good thing. Glue is super hard and abrasive and probably equal to 100 times as much wood passes.

Not sure I buy into that... at least not enough to worry about it.

Also, I don't think you can throw around the term "glue" in the general sense when it comes to plywood. The stuff they use isn't exactly carpenters glue, and it's so thin, I suspect it's a non-issue.

In any case, I'll stick to my first statement. :-)

Exactly what I did with my inserts bit did use 1/2" baltic birch on a JTAS

Did you rabbett out the bottom to fit? The depth of the leveling flange to the top is 3/8".

MJ

Instead of rabbeting, you could simply drill out sections/recesses for the flanges with an appropriately sized Forstner bit. Even if the flanges are much longer than wide, you could drill side by side holes down to 3/8", leaving 3/8", and clean up the resulting recess with a knife or chisel.

An old tip for leveling ZCI I first saw on this newsgroup, but can't remember who to credit: Just put a blob of hot-melt glue at the correct spots on the bottom of the insert, press down into saw so it's just above flush, then hit the blobs with a block plane or sandpaper if necessary.

That's an awesome idea. Instead of sanding, I guess I would try using a couple rulers or other straight edges to push it down flush and hold a few seconds while the glue dries.

If it didn't work the first time, you just pop off the hot glue nubs and try again.

That's an excellent idea. Much better than resetting the router table. I'm going to try it over the next week.

Thanks for that tip.

MJ

In my case the depth on the saw is just over 1/2", so no rabbeting.

Might have been me as I did that many years ago. However I sanded the blobs until the fit was correct. I later went with putting screws on the bottom.

Might want to rethink that, it will essentually glue your insert in place. Put the globs of glue on the insert and then sand the globs to proper thickness after they harden.

The hot glue I've always used is pretty easy to pop off.

Yeah it pops off easy.... but it is glue, right? And you are going to apply it and squeeze it between an insert and the table saw tabs, and then how do you pop it off if it has glued your insert in place?

A. Wax the TS insert fingers first? B. Whack it from below? C. Use the finger hole to pry it off? D. Don't use epoxy? E. All of the above?

AFAIK, we're talking about drops of hot glue on 4 flanges. In a way they are like the little rubber feet you might find on the bottom of a lamp.

You mark where the tabs are on the insert, or you squeeze a drop on each tab/flange. Press the insert down with a straight edge so it stops flush with the table top. It'll dry in 20 seconds.

Here's another idea. Put a piece of scotch tape on each flange, before this procedure. Glue dries to the insert and not the flanges.