# Tablesaw blade alignment with miter slot



## woodnthings (Jan 24, 2009)

Let's make sure that the blade is parallel to the miter gage slots.
If you have a steel graduated ruler say 12"or longer, place it between the blade and the right hand slot and try to get it either touching the teeth the same way or missing all the teeth and in the gullets, blade full up. Measure over to the miter slot from the right side of the straight edge front and rear without moving it, use magnets or tape it to the table if need be, securely up against the blade. You can use a calipers or another straight edge or a pair of dividers. What do you see? Two different measurements or is it the same front and rear? By using a 12" or longer, straight edge you get more of a pronounced indication of the parallelism or lack there of between the two. If the measurements are different then you must bring the trunnions into alignment with the miter slot, by loosening 3 bolts and pivoting on the one that is indicated. This is tricky and may require several attempts. This procedure may or may not be covered in the owner's manual. There are different ways but like I said the longer straight edge will show the difference more readily.
:thumbsup: bill 
__________________


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## Leo G (Oct 16, 2006)

That is not exactly the best way to do it. If you know that your blade is perfectly flat and your arbor has zero runout then it will work.

You should be checking the parallelism of the slot/blade from a single tooth on the blade for the most accurate measurements.


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## woodnthings (Jan 24, 2009)

*Exactly Leo, however*



Leo G said:


> That is not exactly the best way to do it. If you know that your blade is perfectly flat and your arbor has zero runout then it will work.
> 
> You should be checking the parallelism of the slot/blade from a single tooth on the blade for the most accurate measurements.


Most people can't change or fix the "run out" on the arbor themselves nor can they change or fix the "flatness" of the blade. Most people can't measure within 1/1000 of an inch with tools other than a vernier calipers, so this is a simple method to get you in the ball park and to check for major misalignments. Like I said there are other ways......:yes: bill


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## Leo G (Oct 16, 2006)

It's a very good approximate and in most cases will work good.


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## Sleeper (Mar 24, 2009)

Leo G said:


> That is not exactly the best way to do it. If you know that your blade is perfectly flat and your arbor has zero runout then it will work.
> 
> You should be checking the parallelism of the slot/blade from a single tooth on the blade for the most accurate measurements.


 I’ve always checked my craftsman the way Bill has shown and I’ve never had to make an adjustment in 20 years. Now that you have my curiosity aroused, just how often is an adjustment necessary? :confused1:


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## woodnthings (Jan 24, 2009)

*Once every 20 years!*

And then only if you smell burning wood smoke, experience kickback, or drop the saw more than 10 ft. I think if you didn't have anything to do during a blizzard or on a rainy day and you wanted to fiddle around for grins. It only takes 2 minutes to set up the straight edge and measure, so why not. The real fun comes when you find out there is a problem/difference in the two measurements.:yes: bill


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## niki (Jul 16, 2007)

Hi Woodnthings

I also use this method....but, as the others said, it's "almost"....

By extending the blade line to 24" (in my case 30") and checking the distances at the ends of the straight edge, you can minimize the error (misalignment)....well, instead of measuring the error (misalignment) over the 8"~9" of the blade, you are multiplying it a lot by checking the error over 24"...

You can see one example here
http://www.ridgidforum.com/forum/showthread.php?t=15608

And another example here
http://www.ukworkshop.co.uk/forums/viewtopic.php?t=22502&highlight=

Please note that in both cases, I'm lifting the straight edge off the table (to cancel any drag or binding) and, I'm using a caliper for better accuracy......and I think that if you get some 0.002"~0.004" on the 24", you are good to go...on 8"~9" of the blade, you'll get much less...

I call the above adjustment/test "Static Check"...

After I finish the "Static Check", I like to fine tune (or fine test) the blade using the "Dynamic Check"...yes, yes with the blade running at full speed...with the "Dynamic Check", all the Arbor run-out and the blade run out (and every blade has a run-out) are already "Included"...you can see it here
http://www.ridgidforum.com/forum/showthread.php?t=20188

By the way, all the checks/tests should be done with the blade a "Full High" position....correct me if I'm wrong but, on the pictures, your blade doesn't look to me at "Full high"...

Regards
niki


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## woodnthings (Jan 24, 2009)

*You are correct*

The blade was not at full height for the photo, I would have had to cut through my "zero clearance" insert a little deeper for the photo. Good observation.:thumbsup: BTW. I just came up with this idea on my own based on simple physics and had never seen it used anywhere prior. Great Minds Think Alike.....well, are at least thinking!:laughing: bill


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## Northerner (Jun 9, 2009)

i will have to try this, cause i have noticed my splitter is off by a very
long way and i was wondering if the blade can somehow be moved to
put things back in alignment. but i will have to check it with the miter
slots and see how far off it is.

thanks for the tip.


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## Tony B (Jul 30, 2008)

Northerner said:


> i will have to try this, cause i have noticed my splitter is off by a very
> long way and i was wondering if the blade can somehow be moved to
> put things back in alignment. but i will have to check it with the miter
> slots and see how far off it is.
> ...


I would think that the few thousandths of an inch that your blade may be off would have little to no effect on your splitter. Your blade should be aligned with your miter slots and *NOT* with your splitter. That should be a separate issue. 
If the measurements are vastly different and you have to bring the blade into alignment with the miter slot, *loosen all 4 nuts/bolts* on the trunnion. Figure out which one would be the one you will be pivoting from, depending on the motion the trunnion will have to rotate and put moderate tightening on it. Just enough where it doesn't slide. I wish I was in my shop so I could take a picture of my shop made alignment gage. Anyway, as you tighten each nut/bolt ever so slightly your alignment will change. Just keep rotating your wrench from one nut/bolt to the other while checking your gage. It should only take about 10 to 15 minutes to align but it sure is one PITA. I have recently done this on my saw and then on a friends saw. In all of my years of woodworking, this was the only 2 times I did it. They make a gizmo that could be put on your trunnion that will allow for the slightest adjustment. I cant remember if Rockler or Woodcraft sells it. When I wanted it, they were out of stock so I did without it.
I would strive for no more than 2 thousandths of an inch on the length of a blade. One thousandth is much better but at some point you just have to call the job "done". It is important that the 1 to 2 thousandths of an inch off is on the side of making the rear of the blade the further one from the slot than the front. If it is the other way around, it will be more prone to pinching the wood and kicking back. 
Mine had gone out of alignment when I was tilting my blade to 45 degrees and I understand this is quite common although it only happened to me personally just once.


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## Northerner (Jun 9, 2009)

i know to get the blade in line with the miter, but what got me to notice all this was the splitter and how far off it was.
im not talking about any measuring the blade and splitter, im talking you can see a huge difference in angle. so i got to
wondering if the trunion can be moved or the front splitter mount can be moved? im partially disabled and i will have to
get someone over to help me with this cause im sure we would have to come up from underneath to work on stuff?

thanks


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## woodnthings (Jan 24, 2009)

*Suggestion*

If you make the measurements as shown in the photos and determine the blade is parallel to the miter slots, you can use the same method (straight edge) to line up and adjust the splitter. By shimming front or back of the splitter and adjusting nut, you should be able to make the appropriate adjustments without shifting the arbor/trunions, which will only screw up the blade adjustment that you just made. Any saw which requires shifting the arbor to adjust the splitter need some serious re-engineering.:thumbdown: Don't forget the splitter should not not be the same thickness as the blade. It should be about as thick as the plate thickness of the blade and centered.
See what you can see and let us know. OK? :thumbsup: bill


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## frostr2001w (May 21, 2009)

Thanks for the great tip! It makes perfect sense to me.


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## unburled (Mar 10, 2019)

For those here who are concerned with mitre/blade alignment in terms of thousandths of an inch, then a first step is to make sure that the edge of the ruler being measured off deviates less than, say, +- 0.001" from the line of blade contact..


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