Table Saws: What does flat mean?

[jteneyck]

I purposely didn't reveal specifics fearing that it might color your opinion about what flat should mean with regard to table saws. Mine is a brand new R4512 Ridgid. Haven't even plugged it in yet. I hope you can see my drawing. This forum used to let you upload pics directly. The red area is low and maxes out at .023". I'll give 'em a call. I suspect they'll say it's within limits.

image

If 0.023" is within spec. I'd get my money back and buy something else. 

John

[JGrout]

.023" is around 1/64" 

it is cutting  wood, that is flat enough

could it be better? probably. 

should it be better? maybe. 

Will it still cut wood? absolutely

[Delta007]

A decent max table tolerance would be .010" left to right; .010" front to back; .015" corner to corner. Notice: MAX...not average, or expected... this or anything less should not be able to affect your work.

Also, make sure that you aren't measuring high spots by pushing down on the end of the straight edge and trying to measure the resulting gap at the other end. That can take you places that you needn't go.

My 2 cents...

[Robert Adams]

It's good enough. Too many people are looking for cnc machine shop tolerances on woodworking equipment and it isn't needed.

[cvillewood]

I'd return it. That's almost maxing out most feeler gauges. Surely Ridgid's QC is better than that. I don't remember exactly, but Grizzly's is something like half of that?

[WilliamHodge]

I test machines with the cutters running. The only way to do this is to just run some wood, and measure it.

The other half of the equation is the required accuracy. What are you building?

[Steve N]

What did the saw cost you? Being it's 2017 and perfect castings from Taiwan/China have never reached our shores I ask this as a serious question. If it's over 3K then maybe you have wiggle room to complain about flatness. If it's a 700 dollar saw I don't think you do, unless it is domed, or has a wallow so pronounced it causes safety concerns. I'm sure you have noted the majority have answered if it didn't affect performance it isn't an issue. That would cross the entire industry as being the correct answer.

[knotscott]

Let test cuts on wood be your guide.  If you have deviations that are affecting the cut, then there's an issue....if not, make some dust and don't fret about it.  Also, be sure that any flatness issues aren't correctable by shimming the wings before you pursue any warranty support.

[cvillewood]

I don't agree with the test cut and see idea. What if the low spot is in an area where an issue only arises when a certain type of cut is made? What if while pushing the board through it lifts the board and causes a kickback? I know that's likely not to happen, but that'd be part of the case for a new one.

[JGrout]

I don't agree with the test cut and see idea. What if the low spot is in an area where an issue only arises when a certain type of cut is made?  What if while pushing the board through it lifts the board and causes a kickback?  I know that's likely not to happen, but that'd be part of the case for a new one.

I would agree if the issue was more pronounced 

That said being off 1/64" on a cut that likely will be further refined once off the saw is picking nits.

you can sand a 1/64" bevel on an edge for example 

or plane it the same way. 

comparing  wood to machinable solids like metals or plastics even is an apple and orange analogy 

they should not be treated the same. you certainly can strive for that perfection but the craft will still not conform to the same rules. 

JME

Joe