Saw Top Tolerances/G0691

[greg decker]

Just unpacked a new Grizzly G0691 table saw and immediately put a straight edge on it. Side to side OK. Front to back I measure a .010" dish in the area just before the blade in the center. Front to back, measured on each side slightly less about .080". I'm disappointed in the measurements and haven't called Customer Service yet. What are acceptable tolerances in your opinions? This may have already been discussed (I'm sure) in other threads. Everything else came through shipping (UPS Freight) without a scratch and in great shape. Thanks.

[Rick Lizek]

PM allowed .015" on their 66 tops. The old Oliver allowed .010" on their 16" jointer tables. .010" will not adversely affect your work. Woodworking machines do not use the same tolerances as metal working machines. A worn and beaten metal working machine is typically better than a new woodworking machine.

Why do people ask on forums before calling the company to find out what their tolerances are?

[Jeff Willard]

Front to back I measure a .010" dish in the area just before the blade in the center. Front to back, measured on each side slightly less about .080".


Less? I think that's 8x more. Ennyhoo-IIRC, Powermatic allowed for .01" diagonally on the spec sheet that came with my 66.

[Jim O'Dell]

I'm sure the second number is supposed to be .008. As far as asking what the tolerances should be, I'd ask the same thing before I talked to the manufacturer. Other wise, I wouldn't have any idea if what I was asking was right or not. And it sounds like the other tolerances quoted say that this is acceptable. At that point, gaining that information from an unbiased source, I would probably decide it was ok, and not to even ask the manufacturer about it. It's not like he came on here bad mouthing Grizzly. He states what he measured, and asked what the tolerances should be.
Congrats on the saw, Greg. I'm here drooling all over my keyboard as I type!! Jim.

[greg decker]

Yes...you' guys are right, in a rush to type, the second measurement should have been .008"...sorry. I realize that on through cuts it won't make a difference. But when cutting dados the cut will be slightly convex as the saw blade cuts deeper in the beginning and end of the cut. That doesn't seem to be acceptable to me. I have a Grizzly 8" jointer and the bed is dead on and I'm completely satisfied with that machine. I think Grizzly puts out a great product. That's why I went with this saw.

[Barry Vabeach]

Gregg, I am a little confused. I see people measure flatness and say they saw a dip and I wonder why it matters. I agree with you point that on through cuts it makes no difference. On dado's, I still don't see how it can make a difference unless the dip is so large that over half the board can fit in the dip at one time. It is like those cast iron grid sidewings - each of those had dips of a few feet, but it wouldn't have any impact since the wood slides of the tops of the grids and doesn't even notice it is open to the floor below. IMHO, if you observed a large sized dip, the size of a playing cards or larger, or even worse a hump in front of the blade that could be problematic since you could be setting up the cut with the stock in the dip, or on the hump, when cutting tenon or shoulder but by the time you got the the blade the cut wouldn't be the same. If it is a small dip, like a quarter that size, I wouldn't worry about it.

[greg decker]

Thanks guys for responding..... A couple of things....I took my time to verify the measurements (calming down and not rushing). Maybe a dip is not the right term to use to describe the table top variations I'm measuring. The whole table is warped from front to back...left side front to back .012", center front to back .011", and right side front to back is .060" With this much variation the table extensions which are flat will not have each joining edge flush to the table.

I call Grizzly tech services and asked what their standards are and the rep said the industry standard is .006"/ft and .015" - .020" overall. He also suggested to attach the extensions with 2 bolts and then C-clamp the other end to force the edges flush. I'm scratching my head wonder why I should have to do this on a new saw.

[Tom Hargrove]

Greg -

I think your quest for flatness is beyond the tolerances of most woodworking projects. Solid wood is going to move more due to seasonal movement than the variations you mention, and the possible voids in dadoes that you are concerned about will probably not be discernable when finish is applied to the project.

This is clearly my opinion, but I would rather work with the tool in the condition you describe than go through the hassle of crating it back up for a return to Grizzly (as well as the uncrating when the new one arrives) and/or the work involved in replacing the table.

I would try some test cuts (rips, crosscuts and dadoes) to see how the saw actually works in the shop before trying to fix or return the saw. If the work pieces coming out of the saw are unacceptable, by all means do what is necessary to fix or replace the saw.

[Andrew Whitson]

...He also suggested to attach the extensions with 2 bolts and then C-clamp the other end to force the edges flush. I'm scratching my head wonder why I should have to do this on a new saw.

This is common practice to align extension wings to the main table, even on brand new equipment. I have used clamps & cauls in the past, and now I usually just use a deadblow hammer and knock the tables into alignment after snugging the bolts. Most saw manuals describe this procedure.

As to your .060 out of flat, that's not good in my opinion. I wouldn't sweat under .020 unless I saw it effect cuts, but .060 is a bit concerning. Personally, I'd try shimming the table to even up the left and right sides (not sweating the overall front to back dip), and possibly attaching the extension wing to see if it helped the situation.

Your new saw, your call - assuming you've measured correctly, you've heard Grizzly's tolerances straight from the source, and I don't think it unreasonable to pursue a "fix" with Grizzly.

Cheers,
Andrew

[Shiraz Balolia]

As to your .060 out of flat, that's not good in my opinion. I wouldn't sweat under .020 unless I saw it effect cuts, but .060 is a bit concerning.......
Cheers,
Andrew

I think he means .006" (that's what he PMd me).

[Andrew Whitson]

Ah...if the measurement is .006 (not .060), then I would say I don't think there is any defect to speak of, and I wouldn't have any concern using and enjoying the saw.

Cheers,
Andrew

[Gary McKown]

Yep. Unless he has the best straight edge in the world, traceable to NIST standards and verified within a few minutes of making the measurements, how much of 0.006" over 27" difference is due to the measuring tool, not the device being measured?

Also, how much variation could we see by distortion of the tabletop from shimming/ bolting it to the cabinet? No metalworker here, but I would bet it is more than the measurements noted in these posts.

[Noah Katz]

Greg,

It's hard to predict what the effects will be - why don't you make some dados and measure the depth variation and see.

[greg decker]

Yeah again I can't type.... the correct measurement is .006". Shiraz Balolia assures me that this is not a problem and if it was they would certainly replace the top. I'm going to continue to put the saw together and put it to work. If I have any problems I'll pursue it then. Thanks to all who responded with thoughts. I'm new here but find myself checking in quite a bit....a lot of great craftsmen and knowledgeable people are posting and very interesting.

[scott spencer]

Make a bunch of cuts and see if there's an issue before doing anything about it...it'll likely amount to nothing. Your wood will probably move more than that by tomorrow ;).


Blade and fence alignment are another matter....get those spot on if you can.

[Barry Vabeach]

Greg, I agree with your decision. In addition, I don't disagree with your approach - you opened it and as you did your assembly you checked it out - you would have hated to spend a lot of time assembling it and then checked it and found an obvious defect. Next, when you found something that was questionable, you posted here seeking opinions about acceptable tolerances- I think one of the best advantages of these types of forums is you can find out in very short order whether a certain observation is an issue that should prompt a complaint, or something that will never impact your use. I hope you enjoy your new saw.

[glenn bradley]

You're getting good advice here. I would add that cast iron is surprisingly flexible. The measurements you have with the wings off could change with the wings on. The last teardown I did on my saw allowed me to go through the setup again. I shot for flat as possible and aligned at 90* and 45* with just the cabinet and top assembled. This made it much easier to adjust the blade alignment by shimming the table.

Once I was happy, I added the wings and all the other stuff that hangs on my rig. There was then some additional tweaking to get me back to what I wanted at 90* and 45*. This is not as much of a grand effort as it sounds but, it does take some time. The initial setup and alignment of your saw is a great time to exercise patience and thoroughness. If you do, it will be a joy every time you use it. I love my saw more than ever now.