Measuring cut height of table saw blade

[Nick Shattuck]

Anyone have any good tips on measuring the height of a table saw blade before making a cut? I have a wixey digital height/depth gauge that I use now, but it's a little awkward to use on a circular blade due to me not knowing if I'm measuring the peak tooth at its peak height. I can get really close, but I still have to make a test cut and usually have to adjust a hair and test again to get the cut to the depth I want.

Is there a better way to do this? Is there a specialized tool I could buy for this?

[Dick Mahany]

I use the rear depth spine on an inexpensive digital caliper. Works perfectly for me.

[Nick Shattuck]

I use the rear depth spine on an inexpensive digital caliper. Works perfectly for me.

How do you know that you are measuring the peak of the blade? I'm assuming you do it like me and set your gauge near the center of the blade and roll the blade back and forth while slightly moving the gauge back and forth until the gauge covers all teeth that pass below it. While this works, I'm curious if there is a clever trick or perhaps a tool that makes this quick and idiot-proof.

[Bryan Lisowski]

I am going to assume you mean on a non through cut. I set a small combination square to the desired height then raise the blade until it just contacts the square.

[glenn bradley]

Dick's method has the same concerns as your commercial gauge and the same as mu shop made one.

depth-gauge-TS.jpg

Until I got the hang of identifying Top Dead Center on the blade, I used a helper. I drew, with felt pen, a line from (on a 40 tooth blade for example) tooth 1 to tooth 21 and tooth 11 to tooth 31. This gave me a line that I could eyeball as perpendicular assuring that I had the tooth at TDC. Let me see if I have a picture of this . . .

Hmm, I don't but, here's a quick SketchUp. You get the idea.

40T with Marks.JPG

I will also add that I find setup blocks particularly valuable for this and a lot of other "measure by feel" situations. I keep a 1-2-3 block and a set of 4" Whiteside brass setup blocks at the bench, and the tablesaw/router table areas.

[Matt Day]

KISS. Make a cut on a scrap piece and measure it.

[Ron Citerone]

KISS. Make a cut on a scrap piece and measure it.

That's what I do too, especially on cuts that you really wnt to be exact!

[Gary Ragatz]

I use a set of Kreg router setup bars. They work fine for me, but it will depend on what level of precision you need - the Kreg bars are in 1/16" increments.

[Rich Engelhardt]

KISS. Make a cut on a scrap piece and measure it.

I do similar.
I use a digital caliper on a piece of scrap to measure the height I need.
Then I clamp the scrap to the fence and, with the saw running, I slowly snug the fence/scrap up to the blade & raise the blade up till it hits the mark.
Then I go just a hair beyond the line and lock it down.
No matter how hard I try or how tight my feather boards are (or how much force I put on the Gripper) - - for some reason the blade always seems to lift the work off the table just enough to spoil the fit.

After that, I run a test cut - then remove the marked scrap from the fence and stick it on the test cut to see how the fit is.

[Nick Shattuck]

Well it looks as though I'm not missing anything here and it's just one of those things we just deal with even if it takes multiple steps. I mean, I can use the DRO on my planer to set a repeatable, accurate height in one step, use one on my table saw fence to set a repeatable, accurate width in one step, I can adjust blade tilt with a angle DRO, but I can't set blade height with one.

I wonder if anyone has fit a Wixey planer height gauge with the remote display to a table saw lift. It would be easy enough to calibrate. It seems like it would be possible to do.

[Dick Mahany]

How do you know that you are measuring the peak of the blade? I'm assuming you do it like me and set your gauge near the center of the blade and roll the blade back and forth while slightly moving the gauge back and forth until the gauge covers all teeth that pass below it. While this works, I'm curious if there is a clever trick or perhaps a tool that makes this quick and idiot-proof.

I simply very gently place the caliper body on a tooth near top dead center and with a slight roll forward and backward, find the max height. I also have my zero clearance throat plate set exactly level with the table top. Always seems to work just fine.

[Jacob Reverb]

KISS. Make a cut on a scrap piece and measure it.

That's what I do. Get it close with a rule, then test.

[johnny means]

It's easy enough to find TDC, it's simply going to be the middle tooth.

[Nick Shattuck]

This guy made his own using an accelerometer, which I think is ingenious (in that a tilted blade doesn't affect the results). It seems relatively simple so I'm surprised someone like iGaging or Wixey hasn't manufactured one.

[Dan Friedrichs]

This guy made his own using an accelerometer, which I think is ingenious (in that a tilted blade doesn't affect the results). It seems relatively simple so I'm surprised someone like iGaging or Wixey hasn't manufactured one.

Nick, that's really cool! I agree - the accelerometer is genius. I've always wanted a DRO for height, but assumed that the raising mechanism wouldn't have a good mounting point (for a traditional caliper beam-style sensor) that moved 1:1 with blade height.