zero clearance insert

[charles mathieu]

Hi there ! Is there any way to make a zero clearance insert for my table saw without using a dado blade ? My 10" blade will not move far enough below the table to start the cut in the insert. I don't have a dado blade so I'm looking another easy way. Any tips ? Circular saw blade etc..

Thanks !

[Cary Falk]

Use a router to remove some of the material where the blade touches. Outside blade to a 6" or 8" dado stack.

[John Nordyke]

If you have a router, you can route a dado on the underneath side of the insert, most table saws will retract enough that you can then get clearance. You can also (please be careful) start with the insert installed on the end nearest you and the "far" end lifted up in the air. Clamp something to the table surface on the end nearest you to act as a stop, bring the fence over to rub the right-hand side, and retract the blade as far as it will go. Start the saw, and carefully lower the insert down onto the blade.

[Bryan Lisowski]

If your talking about making the cut after you fitted your new insert, you could use a 7 1/4 blade and then use your 10" blade.

[Dan Forman]

I had the same problem, ended up buying an eight inch Freud glue line rip blade. That not only gave me a a rip blade that I din't have, but because the teeth are flat on top, it can be also used for finger joints and clean bottoms on grooves and notches. If you ever make a ZC insert for a bevel cut, you will still need to use a router to eat away some of the bottom surface of the insert for clearance.

In cutting the slot, once the 8" blade breaks through the insert, I stop the saw and swap the 10" back on, and finish the cut with it. You will want to cut a notch in the back for your splitter too. Make a mark on the insert where the splitter will come through, and don't cut any further than that. Raise your blade to it's highest point so it will cut as close to vertical as possible, that will leave the maximum amount of material between the two cuts.

You can park your fence over the right side of the insert to hold it in place so that it doesn't lift when you are bringing the blade up, I use a couple of thin wedges between the fence and the insert to prevent it from lifting.

Dan

[Von Bickley]

If your talking about making the cut after you fitted your new insert, you could use a 7 1/4 blade and then use your 10" blade.

That is how I did it.....

[Yonak Hawkins]

Setting the front edge of the insert down against the front edge of the opening, can you lower the insert down onto the blade ? Be sure to keep the insert perpendicular to the blade the whole way.

[George Bokros]

Setting the front edge of the insert down against the front edge of the opening, can you lower the insert down onto the blade ? Be sure to keep the insert perpendicular to the blade the whole way.

Sounds dangerous to me.

[Lee Schierer]

Setting the front edge of the insert down against the front edge of the opening, can you lower the insert down onto the blade ? Be sure to keep the insert perpendicular to the blade the whole way.

Whoa, this is really dangerous and I would not recommend it. IMO It is never safe to lower a piece of work onto a moving blade by hand. With a throat insert your fingers are going to be far too close to a moving blade. Save the deductible on your health insurance and go buy an 8" blade with the same width teeth.

[Yonak Hawkins]

Whoa, this is really dangerous and I would not recommend it.

That's why I asked if he could to do it. Everyone has their own confidence threshold. I really don't know charles's level of competency.

I have done this maneuver many times and am comfortable doing it. The hands are nowhere near the blade if you know what you're doing. The biggest concern is keeping the plate perpendicular (a jig can help if you don't trust your eyeball) so the blade doesn't bind.

Let me ask you this, Lee : How do you hold the insert when you are raising the blade up through it ?

[George Bokros]

Let me ask you this, Lee : How do you hold the insert when you are raising the blade up through it ?

Don't know how he does it but I clamp a piece of scrap to the table over the insert to the side of where the blade will penetrate.

[Nick Decker]

Don't know how he does it but I clamp a piece of scrap to the table over the insert to the side of where the blade will penetrate.

Yup, I've done it that way or just clamping a piece of plywood over the whole thing.

[Charles Lent]

A smaller diameter blade is the safest way. I use a 7 1/4" blade and raise it just enough to break the surface. Then I switch to the 10" blade of choice to finish the cut. I label the bottom of the ZCI for the blade that I use it with and have different ZCI's for each blade and each common width dado. I make about 6 more blank inserts whenever I run low so I will have them when one wears out or when using a new blade.

Charley

[Lee Schierer]

Let me ask you this, Lee : How do you hold the insert when you are raising the blade up through it ?

My ZCI has replaceable inserts and it is held in place with a screw so I simply raise the blade through a new insert, no clamping is required.

If I had a different insert I would clamp the new insert in place over the old one or use a smaller diameter blade.

Lowering a piece of wood over a blade that is moving by hand is dangerous even if you are comfortable doing it and have many years of experience. You can't guarantee your rate of feed and you yourself admit that controlling the angle is difficult. I tried that once and a little twist in the grain caused the blade to grab the wood and when the saw ripped it out of my hands, the pressure I was applying to hold onto the piece caused my finger to flick across the blade that was at least 10 inches from my hand. It took 21 stitches to close up the finger and I have no loss of motion or any other permanent damage. I had over 15 years experience using table saws and other power tools without injury at the time.

[Matt Day]

7 1/4 circular saw blades are a good idea. For full kerf 10” blades you’d have to stack 2 or 3 together.