Adding set to a table saw blade

[Bob Gramann]

I had the Blade Manufacturing Company make me a 10" table saw blade for cutting .023" fret slots. We agreed that the edge of the blade needed to be a hair smaller than .023" to cut that kerf and settled on .022". What they sent me was .020" at the edge. It cuts a very clean slot between .021 and .022 in width. Anybody have any technique for putting a .001" set on the teeth of this blade? I have considered getting a saw set tool but I worry that it won't be able to reliably make a set this small. I have also considered filing a depression in a piece of steel to use as an anvil and tapping each tooth into the depression with a punch. Has anyone done this before?

[Barry Daniels]

I have a set tool for hand saws and it is not very accurate. I have intended add more set to my Stew-Mac circular fret saw blade but I have not done it yet. I think the anvil approach would be much more accurate. I planned on making a pivot hub for the blade so that every tooth ended up at the same spot on the anvil. A little tap with the hammer should be sufficient.

[Charlie Schultz]

I have the Stew-Mac blade too, and probably the same set tool that Barry has. It does work, but as Barry said, not very accurate and a bit of trial and error is required (mine still cuts a little too narrow).

[Bob Shanklin]

I have the Stew-Mac blade and use it in my Delta cabinet saw. Cuts like a charm for medium(.023") fret wire.

Bob

[David King]

I just set mine by feel with a pair of needle nosed pliers. It's doesn't have to come out with a perfectly uniform set as any wayward teeth will soon get pushed back in line with the others.
You could make an anvil and spindle setup with a set screw adjustment under the dip in the anvil and mount the punch in the drill press vise with a locating pin under the anvil that mounts to the DP table.

The Stewmac blade works great if your fret wire all comes with a .020 tang width. My experience with the SM blade is that it starts the cut at about .027" due to vibrations in the blade and arbor but the kerf quickly drops to .023" as the wood dampens the blade. If you slot your boards after they are tapered you'll sometimes find that the leading edge of the board won't hold fret ends down very well especially in softer woods, due to the wider slots. Trimming the board edges later takes care of this. I made a birch plywood damping stabilizer disk that solved the wobbling for me.

[Clay Schaeffer]

Try it without the blade stabilizers. If you have a poorly tuned saw it might get you a few thousandths.

[Bob Gramann]

I haven't been in much of hurry to fix this--I slotted all of the boards for my current projects before I replaced the saw. The blade needs no stabilizers and the saw is tight. I like both the drill press and the pliers ideas and will be experimenting soon. You folks saved me the expense of getting a set tool.

This blade is similar in design to the StewMac blade, which I have. My experience is much like David's. I've always tapered after slotting--not only is the entry width problem solved, any tearout from entry or exit is cut off, too.

[Bob Howell]

Years ago I read a quick and dirty way to add set to a saw was to put a flat blade screwdriver between the teeth and twist. I have never tried it but it may add what you need. Wild thought.

[Bob Gramann]

Excellent idea. I'm already massaging it to figure out how to limit the twist--I don't need much. Thanks.

[David King]

I'd worry about the screwdriver technique causing micro fissures down between the teeth.

[Barry Daniels]

I need to fret some boards so I decided to give my Stanley blade set tool a try. I quickly realized that a circular blade did not register against the tool very well so I glued on some wood shims. They registered against the blade teeth fairly well.

[Barry Daniels]

The saw set worked surprisingly well on the circular blade. One thing I discovered (and I seem to remember this happened to me when I last used the tool a couple of decades ago) that it is really easy to over set the teeth. Adjust the tool so that it seems like you are not moving the teeth at all. Maybe just a thousandth or two. You will be surprised how much set the teeth will actually take. I had to flatten the teeth and do it a second time.

I will report back how well the set blade cuts.

[Barry Daniels]

Here is a photo showing the tool's working part setting the blade's tooth. It's a bit hard to see but the shiny rectangle is the tool's post pressing the tooth against the anvil. You only want the break angle of the anvil about 0.015" to 0.020" down from the tip of the tooth. That is how you control the amount of set.

[Bob Gramann]

Thank you, Barry. I'm still procrastinating on setting my blade, mostly because I don't need to cut slots yet. I just finished the last instrument in the batch, so, with an empty shop, I may stsrt experimenting soon.

[Brian Evans]

You may find that you only need to set a few teeth to get the slot width you need. I remember from when I started machining that it was common to get a cutter that had been reground, only one or two teeth actually cut, the rest were barely engaged.

[Barry Daniels]

I would not be comfortable with that approach because if most of the cutting was done with only a few teeth they would get dull really fast.

I setup my tablesaw today to test out the blade and my set was still too wide by a lot. I laid the saw blade on a small anvil and used a brass hammer to try to flatten the teeth and it was still too wide. So I used a diamond hone on the side of the teeth and got it back down to where I wanted it. My take away is it is really easy to overset the blade.

Here is a little tool that I make for each size fret wire that I use to test the width and depth of the slot. The bottom leg of the tool gets the barbs ground off.

[Barry Daniels]

Here is my tablesaw setup.

[Bob Hammond]

Just a thought - how about a half-circle paper or metal shim between the blade and arbor flange to add a tiny bit of wobble?

[Bob Gramann]

I finally put the set in the blade today. Figuring that any bend would go back a bit when released, I used a .002" thickness gauge as a spacer and tapped every other tooth with a punch (and a hammer) against another piece of metal, flipped the blade and did the other side on the teeth between. The resulting saw kerf is between .023 and .024" and holds a fret perfectly. I expect the kerf will wear in just a bit smaller. Thank you for all of the ideas.

[Christ Kacoyannakis]

Looks like a beautiful blade. Do you know what kind of steel it is? I don't imagine it has carbide teeth. Is it an 8 or 10 inch blade. I have been trying to get several makers to make me a blade for my Saw Stop (I need a 10) and everybody keeps saying they are working on it, but nobody ever gets it done. Do you mind my asking what the cost was?