Noisy ZCI

[Chris Kennedy]

I recently put in a zero clearance insert on my Craftsman zip code -- I bought the phenolic plate for my saw at Sears, it fits perfectly, and followed the instructions for it (not that they are hard -- install plate, clamp down, and slowly cut through). For the record, this is my first ZCI.

Here's the thing -- the blade makes a racket now. I think I somehow made a negative clearance insert, because it sounds like the carbide teeth on the blade are in constant contact.

My question is then three-fold:

1. Is this normal or is this a sign that something is out of alignment (for the record, everything measures square).

2. I am contemplating tilting the blade a hair and plunging it through the ZCI just to alleviate the noise. Does anyone have another suggestion that would help?

3.. Am I totally wrong? Is this something that I just need to get used to?

Cheers,

Chris

[John Thompson]

When you raise the blade Chris.. you do get zero clearance. Is that all good? Not in my opinion. You will never see a TS that does not have some run-out. So.... the blade is going to slightly touch the phonelic and you get a high pitched whine if you listen carefully.

I personally don't want that to happen as phonelic is very hard and carbide is very brittle. Carbide teeth will dull earlier even if you can accustom yourself to the high pitched whine. So... I take a file and open up the plate in each side of the blade about 1mm to prevent touching.

Now.. you do need to check alignment with the saw off as that should be checked on a new saw and occasionally latter if the saw tells you something is wrong by telegraphing with the cut. But.. I think what you hear is just a plate that has been cut to zero clearance.

Good luck..

Sarge..

[steve reeves]

It's a "normal" sound with the zero clearance insert... mine does it and every other one I've seen (several) exhibit the same sound.

I've not seen any wear issues with my blade.. further I have several of these inserts because I'm a "blade changer" I change blades for ripping, cross cuts, plywood cuts, box joints etc. etc.

Everyone of the inserts makes a tiny bit of noise to some degree. My saw has less than .001 runout and the blade(s) run within a .001" of true to the miter slots. Just one of the nice features of that zipcode saw is that you can adjust the top quite easily..

[James Hart]

Someone here on the creek gave me a great tip that worked for this. Put some duct tape on the bottom of the insert, near the blade slot.
It dampens the whining to the level I don't even notice it anymore.

Jim

[Chris Kennedy]

Thanks for the suggestions. I'll try opening the ZCI a little with a file. I bought it mainly to install a MJ splitter, so it not being a perfect ZCI will not bother me.

I'll double check the saw alignment as well.

Cheers,

Chris

[Joe Scharle]

I make my ZCIs out of MDF and for saw blade use, I use a dado blade for the initial kerf. Dado and molding head cutters cut their own openings.

[Prashun Patel]

I have the same issues on ZCI's. Tilting the blade a little helps, but only if you can tilt it in both directions +90 and -90 to remove a little of the stock.

On the other hand, the whine means you'll minimize your chipout...

[John Thompson]

Chris.. let me clarify what I said about the carbide wear from touching. When you file.. you will see just how hard phonelic is. And we have established it is touching.

What I said about wear is an opinion and not a scientific fact as I have no way to test to see. There is no scientific evidence to say that it doesn't wear it on the other hand to my knowledge. So..

We have contact which produces friction. Having been around auto engine rebuilding for 30 + years I know friction causes wear. It also produces heat as the blade is spinning at over 4000 RPM a minute. Heat is not good either. That's why you see little lines cut in most good blades to help dis-apate heat from the outer teeth toward the center blade blank.

I use my TS mainly to rip and do often change blades. An average of 4 times a day and my saw my run continuosly for and hour before I let it rest to help cool down blades. I spend from 6-10 hours a day in a shop with several sharp back up blades available and one or two at my local sharpener at all times.

So.. you can make your own assumption if friction from a zero clearance does indeed build up heat and does prematurely add to carbide tooth wear. Perhaps a Mechanical Engineer might weigh in on the subject with some scientific finding as my opionion is simply based on common sense formed over 30 + years of using TS's.

Just wanted to make my opinion clear on how I formed it....

Sarge..

[Cliff Rohrabacher]

Make you next one from wood. It'll work better.