Tablesaw Blade to miter slot adjustment

[Ted Baca]

I seem to have read somewhere that, if possible have the sawblade slightly out of parallel with the miter slot. I kind of see the reason if the blade is further from the fence on the exit to help prevent kickbacks.
But what is the rule? I need to make some adjustments but before I go through the full procedure, which way do I want to go? And could I gain the same result by making the tail of the fence swing slightly away from the blade?

[Ryan Sparreboom]

I think the blade is supposed to be perfectly parallel to the mitre slot. The far end of the fence should be slightly out (1/64th) farther from the blade. Correct me if I'm wrong.

[Jason Beam]

You'll get some varying replies, but my strongly physics-oriented opinion is PERFECT alignment - perfect as best you can, that is. Don't deliberately toe or heel out any of them. The fence and the blade and the slot should be as close to perfectly parallel as possible. If it can twist, it can kick back.

[glenn bradley]

Some people toe-out their fence and this may be what you are thinking of. The blade is ALWAYS parallel to the miter slot (unless you plan to never use your miter slots). We have to accept that the manufacturer made the slots parallel so pick one and use it.

You can find scads of info on this here and other places but, in a nutshell and in order (in my opinion):

Assuming a saw in reasonable condition with acceptable tolerances of arbor run out, top flatness, fence rail setup, motor pulley to blade pulley alignment, etc. . . . in other words, there's nothing terribly wrong from the start:
1. Make blade parallel to miter slot at 90* and at 45*
-- This one can be a challenge on some saws so at least get it aligned when at 90*. Mark one tooth on your blade with a felt tip marker and measure from the same tooth at the front and rear of the blade’s rotation.
2. Make fence parallel to the SAME miter slot
-- Here's where some folks go for a toe out. I would only do this if my saw had other issues I could not overcome. Others feel differently.
3. You're done
-- This can take a few minutes or a few hours depending on the saw, it's design and it's condition.

Set aside a reasonable chunk of day to dedicate to this so you don’t feel hurried or get interrupted. The upside is that once setup, most saws stay pretty well where you set them and are a joy to use. The reliability of your setup and the length of time it will stay that way will vary with the saw, whether or not it is moved around much and all that stuff.

[Ben Cadotte]

I try to have my blade as close to parallel as possible to the left miter slot. I had just re-adjusted my saw a couple weeks ago and felt .001" was close enough. The back of the blade is .001" to the right.

After moving the blade / trunions, I then checked the fence. My fence is .002" to the right (back end). I set this on purpose as I don't want binding on the back of the blade. Most people agree that a saw within a couple thousands of an inch is just fine.

If you don't have one, I suggest getting a cheap dial indicator from a local store or online. You can make a simple holder, don't need the expensive kits sold. Another option is to use an adjustable square and feeler guages. Not as easy but works just fine.

[Bruce Page]

I think the blade is supposed to be perfectly parallel to the mitre slot. The far end of the fence should be slightly out (1/64th) farther from the blade. Correct me if I'm wrong.
This is exactly how I have always set up my tablesaw.

[Greg Karol]

don't forget when you do adjust for parallelism that you rotate the blade as you measure, so you take the run out of the blade out of the equation. this way your blade to slot will really be arbor to slot, which is much more accurate then a stamped blade will be. Typically if I can get a saw under .005 parallelism it is good enough. I also typically toe out my fence between .005" and .015"

[Chris Padilla]

I do the same as Ryan and as Bruce but I do not use a saw blade to measure to. I have an aluminum plate I use instead that I bolt on the arbor. Do a search on "Master Plate" and you'll find some interesting responses.

[Ted Baca]

Thank you for your responses and confirmation on the blade/slot parallel question. I think what Chris writes about using some bar stock, machined to tolerance makes good sense. I am using a Forrest Blade and a Align Kit with a dial indicator and I can't get a consistant reading as I rotate the blade back and forth. Any one else using the "master plate" in lieu of a blade? Is the dial indicator too tight of tolerance of am I better off with a good combination square?
Again thanks for the advice.

[Mike Sandman]

If you have a dial indiactor and you're set up to mount it securely on a jig or bar that fits into a miter slot, that's the best choice for aligning both the blade and the fence. Make sure you keep the edge of the bar or jig pressed against the far side of the miter slot, and keep it consistently level whe you move it.

Prior posts have given good advice. Some people prefer to have the far end of the fence toe out away from the blade by .001 - .002, some prefer the fence to be perfectly parallel to the blade. You choice, I guess. Just make sure the far end of teh fece isn't closer to the blade -- that's a dangerous situation.

You might check this link for a step-by-step procedure, although the prior posts have pretty much the same instructions:

http://www.newwoodworker.com/basic/tsalign.html

Mike Sandman

[David DeCristoforo]

"...Do a search on "Master Plate" and you'll find some interesting responses..."

Important if you want accurate results. I have a steel plate that a machinist friend made for me years ago that is "perfectly flat". Saw blades mostly are not, at least not until they are running at speed at which point it's kinda hard to take any measurements....

FWIW I am in agreement with the miter guage aligned with the blade (critical) and the fence "canted" a hair at the outfeed end of the blade (optional)

Also, FWIW I have no dial indicator. I just use a stick (gasp... blasphemy!)

[Ben Cadotte]

Not sure how your doing it but I pick a spot on the blade below a tooth. As I push back the dial indicator I rotate the blade. So the indicator is always on a flat spot on the blade. Reading stays fairly consistant / smooth. If you put it on a tooth, and it has an angled grind on the side, you will get different readings (unless you put the indicator in the same exact spot). So thats why I use a spot below the teeth on the flat part of the blade.

[Ted Baca]

Thanks again, some more! I think where I am getting the inconsistant readings is that I was using a tooth. Ben thanks for pointing out that as a bad spot to pick the reading. And also having the bar tight to the far side of the slot makes good sense too. I guess that I might try the fence out of alignment/parallel by .001 and see if that works. I like the idea of not having pressure against the blade as it is coming up.
Once again thanks to all.:D

[Chris Padilla]

Ted,

Along with the Master Plate that I use, I also have the SuperBar. Find both of them here at Grizzly (http://www.grizzly.com/catalog/2008/Main/321). The SuperBar works very nicely, fits snugly in the miter slot yet will glide along it effortlessly. I use both of these tools to check all sorts of things throughout many of my ww'ing tools. Very handy tools to have although not cheap. Although tolerances for working wood don't need to be 0.001", setting up your ww'ing machines to those tolerances will make working your wood more enjoyable and precise.

[Ted Baca]

Chris
I bought a Master Plate this evening and will try it out this weekend. I already have the Aline Kit with the dial indicator and bars so I am hopefull this Plate will do the trick. Measuring on the blade tooth was my first mistake but that is all behind me now. Thanks again.

[Chris Padilla]

Oh, as far as the fence goes...use a splitter. I'm of the camp that the fence should be as dead parallel to the miter slot as possible. The splitter will take care of any pinching that might go on.

[Bruce Page]

Oh, as far as the fence goes...use a splitter. I'm of the camp that the fence should be as dead parallel to the miter slot as possible. The splitter will take care of any pinching that might go on.
I have never seen any ill effects from having my fence kicked out .015-.020 , I still get a parallel rip.

[Chris Padilla]

I have never seen any ill effects from having my fence kicked out .015-.020 , I still get a parallel rip.

I don't doubt one bit that you do, Bruce, but I still like mine parallel..and I use a splitter religiously...micro-splitter from micro jig. I sleep better at night knowing my fence is parallel! ;) :D