# acceptable runoff of 10" table saw blade?



## AlWood (Apr 18, 2010)

Folks, would you remind me please (looks like I forgot the right number) -- what is acceptable runoff of a table saw (a good one:huh:...) blade? My measurement of a new TS using a micrometer (I am still trying to make sense of my new Craftsman 22114, damn it :wallbash:) gives me 0.01" runoff or wobbling, which doesn't look nice (I know that 0.001" up to 0.003" must be fine, but 0.01"?:blink At which point the runoff may cause vibrations? Is 0.01" beyond acceptable?


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## rrich (Jun 24, 2009)

I don't know how you're measuring run out. If you are using a saw blade, the dial indicator must rest on the same tooth. Run out should be measured at the front of the table and at the back of the table. (I don't know what a TS micrometer is or how it works.)

The things that can affect run out are a bit of sawdust against the arbor flange.

You can also measure run out at the arbor and arbor flange.

I'm trying to remember... IIRC my Jet contractor came from the factory at 0.003 and my Unisaw came with 0.0015 run out. This was measured at the arbor. When I measured the run out on the Unisaw with a good blade, I believe that it was less than 0.003. (I was far more concerned with the blade being parallel to the miter gauge slot than run out. My dial indicator is on a home made slide that rides in the miter gage.)


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## AlWood (Apr 18, 2010)

rrich, thanks. Here is what I am measuring : a dial indicator (I just called it micrometer) is mounted on a miter gauge, and its tip is positioned at a front end of the blade and touches one tooth of the blade. Then I rotate the blade (and dial indicator remaines in the same position) such that the indicator's tip touches another tooth, then yet another one, and so on, until I make an entire circle. The numbers on the dail go up and down; the full difference between min and max I call "run-off" (what you call runout -- most likely your term is right, but I hope my description gives the full picture). Whatever you call it (let us call it wobbling) -- is the number 0.01" (per my procedure) acceptable or not? Could it be the reason for vibrations?


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## woodnthings (Jan 24, 2009)

*This may help*

This link has a number of methods and tools: 
http://www.thewoodshop.20m.com/calibrate_sled1.htm

Quite a few videos re table saw set up and arbor runout:


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## AlWood (Apr 18, 2010)

woodnthings said:


> This link has a number of methods and tools:
> http://www.thewoodshop.20m.com/calibrate_sled1.htm
> 
> Quite a few videos re table saw set up and arbor runout:


Bill, thanks; I knew most of them (I liked though the way one of them is using a wooden plank instead of calibration plate; great!). I essentially used a technique similar to most of them (even a black dial indicator:yes. The guy who wrote sort of review, passingly mentioned the tolerance number for runout I actually recalled -- 0.003". My question still remains : is 0.01" something that is (1) sort of officially indicates a "fatal" defect, and (2) could be actually the reason sufficient for strong vibration?

(BTW -- not that this is important to me with my new saw -- a well advertised PALS fixture to square blade & miter guide on contractor saws is not that great as people who promote it used to claim. I tried it in the past on my old Delta contractor, spent a lot of time and found it inefficient, time-consuming and weak, definitely not worthy money, time and effort.:thumbdown


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## Bob Wingard (Jul 23, 2007)

Is it better or worse with a different blade ?? It is difficult to get a meaningful measurement of blade flatness using your method, because you don't know yet if the arbor/flange are running true.

There are methods posted online showing how to measure and correct for flange runout .. takes a bit of patience, but not all that difficult. If I can locate the article showing the method I used, I will post it.

One thing you might try .. .. . 

Mark your arbor flange and blade with a "witness" mark. Check the blade for runout, and make a mark on the HIGHEST and LOWEST location. Loosen the blade and rotate it 90 deg .. tighten it back down and measure/mark again. Do this at 90 degree intervals .. .. if the blade always indicates the same locations as HIGH & LOW, you probably have a warped blade. If the locations change it's more likely a flange out of true.


I found the link to a GREAT article that is exactly what you need .. .. .. 

http://www.forums.woodnet.net/ubbth...&page=7&view=collapsed&sb=7&o=&fpart=all&vc=1


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