45* ZCI and a 10 in blade

[Chris Kennedy]

I tried to build a 45 degree zero-clearance insert (ZCI) today for my zipcode saw. I used 1/2" MDF, used a flush-trimming bit and it fit perfectly. Since my full sized blade wouldn't fit, I used my 8" dado blade to start the slot, and then I ran into trouble.

I cannot get my 10" blade and the ZCI on simultaneously, even with the slot started. I did some looking earlier and found this thread:

http://www.sawmillcreek.org/showthread.php?t=125529&highlight=clearance+insert

but that dealt with getting the slot started. I experimented with the suggestion in the thread to cut a recess using a router, but at 45 degrees, a 10" blade is about at the height of the table with the arbor all the way down. It is physically impossible to fit the throat plate on -- the blade gets in the way. Maybe it is my saw -- I don't know.

So, for those of you with ZCI's for 45*, how do you get a full sized blade on?

Cheers,

Chris


If I were to rout out a recess deep enough, well, I would have to cut all the way through, thereby defeating the purpose.

[Noah Katz]

Use a smaller blade or releive the bottom of the ZCI until there's room for the 10".

[Glen Butler]

I have always heard that you shouldnet you ZCI's on 45 or a tilted blade for that matter. I don't know why, I just heard you shouldn't.

[JohnT Fitzgerald]

Chris - use the outside blade of a dado set (or some other smaller blade - meaning smaller than your 10" blade) to start the cut, then change the blade to the 10".

[Gerald Jensen]

I don't see how this could possibly work.

The arbor in a tablesaw moves vertically, and with the blade tilted, the slot in any insert you have installed is going to be cut in a half-moon shape.

[Faust M. Ruggiero]

Chris,
Raise the blade, obviously with the saw NOT running. Drop the ZCI on the blade. Lower the blade back into the saw. Hopefully, the ZCI will drop in place. If not, trim the lower 1/4" of thickness into a slight relief angle. That should help.

Gerald,
It works. The blade raises at 90 degrees to the trunnion angle.

fmr

[glenn bradley]

Hi Chris, I have a 22124 as well and the blade is near the table top at its lowest position so I ran into the same problem. I used a dado to hog out some space as you describe. I then used a smaller kerf / smaller diameter blade to just start the slot, barely piercing the surface of the ZCI. This allowed me to put the ZCI in and insert the retaining screw. I could then fire up the saw and raise the blade. I fear all this effort was for not as the actual slot is through material so thin that it gets damaged putting the ZCI in and out. What I have now is a 'close' opening that protects against small strips falling down into the slot and getting launched by the blade. I have found this adequate but it does not give me all the benefits of a true ZCI.

[glenn bradley]

I don't see how this could possibly work.

The arbor in a tablesaw moves vertically, and with the blade tilted, the slot in any insert you have installed is going to be cut in a half-moon shape.

Not on any saw I have owned or operated. Do those little benchtop saws do this?

[Bruce Wrenn]

After using outside blade from dado set, you have one side of the needed opening. With blade off saw, turn ZCI upside down in TS. This will hold it in place. Put a 90 degree "V" bit in your router, and using fence as a guide for router, open up your slot. Be careful that you don't cut into TS top.

[johnny means]

I don't see how this could possibly work.

The arbor in a tablesaw moves vertically, and with the blade tilted, the slot in any insert you have installed is going to be cut in a half-moon shape.

Actually, the arbor moves in the direction of the tilt.

[Chris Kennedy]

Hi Chris, I have a 22124 as well and the blade is near the table top at its lowest position so I ran into the same problem. I used a dado to hog out some space as you describe. I then used a smaller kerf / smaller diameter blade to just start the slot, barely piercing the surface of the ZCI. This allowed me to put the ZCI in and insert the retaining screw. I could then fire up the saw and raise the blade. I fear all this effort was for not as the actual slot is through material so thin that it gets damaged putting the ZCI in and out. What I have now is a 'close' opening that protects against small strips falling down into the slot and getting launched by the blade. I have found this adequate but it does not give me all the benefits of a true ZCI.

Thanks -- I was wondering if I was just going to have to give up on a true ZCI. Since I wrote the post, I have been pondering it some more, and it just looks to be physically impossible without cutting a larger slot.

Thanks,

Chris