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Matt P
12-12-2008, 6:21 PM
I am a novice, with a new Dewalt DW745 Benchtop table saw and a dial indicator.. I measured whether the blade is parallel with the miter slot, and I get runout of about .05. It varies a little each time I measure it.., but usually it's about .05. Is this reasonable? I know I can't expect too much accuracy from a contractor's benchtop saw, and I don't want to drive myself crazy adjusting it.. thoughts?

Thanks in advance,
Matt
Bruce Page
12-12-2008, 6:38 PM
Matt, do you mean .05 or .005? (50 thousandths or 5 thousandths)
Are you checking the same spot on the blade e.g. put a pencil/Sharpie dot on the blade, set your indicator, rotate blade and check the pencil mark again?
Is the blade running true when you turn it?

.05 is way out and needs to be corrected. .005 is still farther out than it should be but probably useable. I have my cabinet TS set up within .001
Jay Brewer
12-12-2008, 6:55 PM
Hi Matt, check it just like Bruce said. If its still out, change to another blade and check it again, and while the blade is off, check the arbor with the dial indicator. .05 is WAY to much, and I would consider it unsafe to use. With that much runout, you could easily see the blade wobbling when turned on.
Matt P
12-13-2008, 1:01 PM
Thank you for the info! I may have misspoke on "runout" - my measurement was that the blade is not PARALELL to the miter slot by .05 (5 hundredths). (I kept the blade stationary, and used the dial indicator attached to the miter gauge to check this). Is .05 really bad for the blade being out of parallel with miter slot? It's a benchtop contractor's saw (Dewalt DW745)
Myk Rian
12-13-2008, 1:18 PM
Like Bruce suggested, make a mark on the blade. Measure from the miter slot then turn the mark to the other side. Measure again. If it is .05 out, that is too much. I try for .001-.002.
Also, keep the indicator in one place. Turn the blade. This will show if the blade is warped, or the arbor is bent.
Bruce Page
12-13-2008, 1:35 PM
Thank you for the info! I may have misspoke on "runout" - my measurement was that the blade is not parallel to the miter slot by .05 (5 hundredths). (I kept the blade stationary, and used the dial indicator attached to the miter gauge to check this). Is .05 really bad for the blade being out of parallel with miter slot? It's a benchtop contractor's saw (Dewalt DW745)

Matt, if you are checking it like Axl & I have suggested and you are seeing .050 then yes, that is too much and it could cause a kickback when ripping. .050 is more than half the thickness of your blade, assuming that you have a 3/32 blade (.093) in your benchtop.
Matt P
12-13-2008, 1:58 PM
yes, but you are referring to runout, what about .05 out of parallel with miter slot??


Matt, if you are checking it like Axl & I have suggested and you are seeing .050 then yes, that is too much and it could cause a kickback when ripping. .050 is more than half the thickness of your blade, assuming that you have a 3/32 blade (.093) in your benchtop.
Myk Rian
12-13-2008, 2:01 PM
Put a mark on the blade. Check it as suggested. That will show if it is parallel with the track.
You must check for parallel by using the same spot on the blade.
Here is a how-to:
http://www.newwoodworker.com/basic/tsalign.html
There is a video at the bottom of the page.
Matt P
12-13-2008, 2:03 PM
ok - i see now! d'oh! thank you Axl.


Put a mark on the blade. Check it as suggested. That will show if it is parallel with the track.
You must check for parallel by using the same spot on the blade.
Chip Lindley
12-13-2008, 6:02 PM
Hopefully, this thread clears up the difference between *runout* and *parallelism* of a saw blade. Two different animals, two different problems!

Next will be aligning the rip fence with the miter slot, once the blade is parallel with said slot.....
Myk Rian
12-13-2008, 6:21 PM
Thankfully, once the miter track/table and blade are aligned, the fence is a cakewalk.
Bruce Page
12-13-2008, 7:36 PM
yes, but you are referring to runout, what about .05 out of parallel with miter slot??
Matt, you have to have a true running blade before you can check the parallelism to the mitre slot.

There is also a master plate that can aid in setting up a table saw.
http://woodworker.com/cgi-bin/FULLPRES.exe?PARTNUM=956-759&search=Master%20Plate&smode=